Campuses:
The database contains summaries of over 500 MXP projects going back to 1970. Data from Kurt's long-standing database was imported to MySQL running on a department server, and is accessed here using the DokuWiki dbquery Plugin.
| Date | Category | Project Name | Project Description | Students | Student1 | Student2 | Student3 | Reference | ProjEqBuilt | RepLocation | RefAIP | Project URL | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2017-12-01 00:00:00 | Condensed Matter Physics | Mӧssbauer Spectroscopy of 57Fe, Fe2O3, and Fe3O4 | The recoil-free resonant absorption of the Mössbauer effect was used in tandem with the Doppler shift to observe and measure hyperfine interactions of 58 Fe, Fe 2 O 3 , and Fe 3 O 4 . The isomer shift, quadrupole splitting and Zeeman effect characterize the spectrum of the Fe compounds and were all measured to be within 2sigma of theoretical values. A quadrature Michelson interferometer was used to determine absolute velocity measurements. | Durgin, Aaron | McCabe, Chase | ||||||||
| 2017-12-01 00:00:00 | Optics | Hong-Ou-Mandel Interference | To produce Hong-Ou-Mandel interference, down converted photon pairs, guaranteed to be distinguishable only in trajectory and position, were sent through an interferometer with adjustable arms. The beam of entangled pairs was combined at a beamsplitter within the interferometer, with two detectors at each output. When physically indistinguishable, interference of the wave functions occurs at the beam splitter due to a phase shift of reflected photons. This produces a drop in coincidence counts between the detectors that can only be explained with a full quantum description of the corpuscular nature of light. | Christy, Jacob | Frand, Mitchell | ||||||||
| 2017-05-08 00:00:00 | Condensed Matter Physics | Annular Resonator to Measure the Speed of Fourth Sound in Liquid Helium | In this experiment, we measured the velocity of fourth sound, a pressure wave which propagates only through the superfluid component of liquid helium II, in an annular resonator packed with Al2O3 powder by inducing fourth sound waves in the helium within the resonator at frequencies between 200 Hz and 10 kHz and observing the resonance frequencies of the system which correspond to the frequencies of standing waves within the resonator. The velocity of the fourth sound waves was calculated from the location of the resonant frequencies along with the known dimensions of the resonator at each of ten temperatures between 2.17 K and 1.5 K. We were able to observe values for the speed of fourth sound which showed the correct overall trend as a function of temperature; however, they were systematically lower than the theoretically calculated values. | Epstein, Amanda Hafner, Elena | Epstein, Amanda | Hafner, Elena | 1730 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_fourthsound | |||||
| 2017-05-08 00:00:00 | Cosmic Ray Experiments | Characterizing the Low Energy Response of the FOXSI silicon X-Ray Detectors | The purpose of our experiment was to improve the characterization of the energy response of the Focusing Optics X-ray Solar Imager (FOXSI) silicon X-ray detectors below 5 keV, as there have been observed discrepancies in this regime. We did so by using a 5.9 keV Fe-55 X-ray source to measure the variation in transmission of low energy X-rays through the detectors' nonuniformly crinkled thermal blanketing. We found that at 5.9 keV, a smooth blanket had an average transmission of .83 +/- .03 and a crinkled blanket had an average transmission of .83 +/- .02, indicating that there was no significant change in transmission with crinkling and that the crinkling cannot have caused the observed discrepancy | Bergstedt, Kendra | Bergstedt, Kendra | 1711 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_foxsi | ||||||
| 2017-05-08 00:00:00 | Misc | Daylight Experiment for Teaching Stellar Interferometry | A quasi-monochromatic, spatially incoherent light source was used to simulate star light. A telescope fitted with masks containing pairs of pinholes was used to observe the simulated star, producing interference patterns. Increasing the pinhole separation produced a change in the degree of coherence of the light and fringe visibility of the interference patterns. Relating pinhole separation to fringe visibility using the van Cittert-Zernike theorem, the diameter of the light source was determined to be 2.33 ± 0.18 mm. This diameter agrees with the actual diameter of 2.31 mm with an error of 1.12% or 0.14sigma, though the data does not fit to the predicted equation. | Hines, Adam Skuza, Nicholas | Hines, Adam | Skuza, Nicholas | 1792 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_stellarinterferometer | |||||
| 2017-05-08 00:00:00 | Atomic Physics | Measuring the Refractive Index Using and Extended Cavity Diode Laser | In this experiment, the index of refraction of a thin glass slide was measured using an Extended Cavity Diode Laser (ECDL). This was done using saturated absorption spectroscopy of a Rubidium cell combined with a change in optical path length inside the extended cavity. Using Snell's Law and trigonometry, the index of refraction of a thin piece of BK7 glass was related to path length changes in the laser. Using a least squares fit, the index of refraction was measured to be n=1.52±0.032. This value agrees with the index of refraction of BK7 glass found literature, 1.51. | King, Brendan Stangl, Sarah | King, Brendan | Stangl, Sarah | 1740 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_refractiveindex | |||||
| 2017-05-08 00:00:00 | Particle Experiments | Efficiency Measurement of thin Plastic Scintillator as an Electron Target | We measured the detection efficiency of thin target scintillator for minimum ionizing particles in order to find the feasibility of an electron event trigger design for the Light Dark Matter eXperiment (LDMX) detector. Cosmic muons were used in place of high energy electrons since they have comparable energy scales. The detection efficiency was determined by comparing the energy deposited in the target scintilla- tor at the time of trigger, which is created by looking at the energy in two thick layers of scintillator on either side of the target scintilla- tor. An efficiency was taken for two scintillators with thicknesses of 3.0+/-0.1 mm and 2.2+/-0.1 mm. We measured efficiencies of 0.88+/0.01 and 0.78+/0.02 for each respectively. Preliminary results of our attempt to determine the location of the muon event in the plane by looking at the differences in energy in each SiPM are also shown. Our results from this experiment will determine if such an electron event trigger will be used in the final LDMX detector. | Dorseth, Mason Poehlmann, David-Michael | Dorseth, Mason | Poehlmann, David-Michael | 1722 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_plasticscintillator | |||||
| 2017-05-08 00:00:00 | Misc | Electrodynamics and Mechanics of the Thomson Jumping Ring | The purpose of our experiment was to construct a model for the motion of an aluminum ring as it undergoes an accelerating force due to a magnetic field from a solenoid coil. We achieved this by measuring a series of height dependent auxiliary functions, and then using second order Euler approximations and Newton's second law of motion to generate a model of the expected motion. We found that our model described the motion of the ring to within 0.42 standard deviations in the regime where the magnetic force is driving the motion. | Chadwick, Taylor Twaites, Alexander | Chadwick, Taylor | Twaites, Alexander | 1791 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_thomsonjumpingring | |||||
| 2017-05-08 00:00:00 | Particle Experiments | Electron-Positron Pair Production | The rate of detection of positron annihilation photons as a function of the thickness of a lead target slab was investigated. A Co-60 gamma ray source provided high energy photons for pair production. Coincidence detectors placed 180° apart on either side of the target were used to identify simultaneous 511 keV photons produced by annihilation. The detection rates were measured for slab thicknesses ranging from 1 mm to 15 mm, and were found to be in agreement with the theory. | Moskowitz, Irene Schmitz, Ryan | Moskowitz, Irene | Schmitz, Ryan | 1720 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_pairproduction | |||||
| 2017-05-08 00:00:00 | Optics | Exploration of the Ball-Rod Physical System Using an Optical Interferometer | We use a Michelson interferometer with a 633 nm HeNe laser to investigate the motion of two steel rods of lengths 39.8 cm and 55.1 cm after being struck by a steel ball. The collision launches an elastic wave through the rod with observable displacements of the end mirror by interferometry. The speed of sound in thin, steel rods was found to be consistent with literature at 4830 ± 10 m/s for the 39.8 cm rod and 4870 ± 10 m/s for the 55.1 cm rod by observing rod lengths traveled within 43 round trip times of the induced compression wave. The evolution of the rod’s motion with time is also analyzed with position and velocity vs. time graphs for the two rods. The rods initially experience start-stop motion due to compression wave dominated movement with no gross rod motion between bursts and evolve to include gross motion as the compression wave transfers energy to the rod. Rod friction is neglected for short timescales less than 1 ms but play a significant factor in slowing the rod subsequently. | Kaissi, Hosni Zhao, Long | Kaissi, Hosni | Zhao, Long | 1754 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_ballrodinterferometer | |||||
| 2017-05-08 00:00:00 | Optics | Analysis of a Vibraphone Bar Using Speckle Interferometry | In this experiment, an electronic speckle pattern interferometer was built, then used to find the nodes of a vibrating vibraphone bar. The interferometer was tested by bending a metal plate and observing the number of fringes seen. The speckle pattern was created by diverging a laser beam and reflecting it off of the object in question and a reference object. To view the nodes or fringes, an image of the unaltered object was subtracted from the object while it was deformed or vibrating. After testing the interferometer by bending a plate, we found the observed number of fringes to match the predicted number quite well, with most predicted points lying within the observed points’ uncertainties. With the vibraphone bar, we calculated the fundamental node locations (as fractions of the total bar length) to be 0.224 ± 0.009 and 0.786 ± 0.004 from left to right. The left node lies within four standard deviations of the value of a tuned bar from literature (0.1929), and the right node lies within five standard deviations (0.8034). | Igl, Alexander Schwartzberg, Levi | Igl, Alexander | Schwartzberg, Levi | 1750 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_speckleinterferometer | |||||
| 2017-05-08 00:00:00 | Particle Experiments | Gamma Ray Spectroscopy | Using a high-resolution, high-purity germanium (HPGe) detector, spectra of gamma ray emissions from radioactive isotopes in sediment samples from Lake McCarrons were taken. By comparing the spectra of sediments from different depths, it was found that there is no significant time dependence of natural radiation over the time frame the sample covers. In addition, no (unnatural) radiation from the fallout of nuclear testing could be detected. | Holm, Tony Meeker, Evan | Holm, Tony | Meeker, Evan | 1721 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17-gammaspectroscopy | |||||
| 2017-05-08 00:00:00 | BioPhysics | Determination of Viscosity Via Dynamic Light Scattering | In this experiment the concept of dynamic light scattering (DLS) was investigated by autocorrelation data analysis. This was used to determine the viscosity of samples composed of glycerol-water mixtures containing nano-sized latex spheres. The autocorrelation function was used to determine the diffusion coefficient, which is related to the viscosity of solutions by the Stokes-Einstein relation. The other parameters in this equation such as the hydrodynamic radii of the spheres were known for this experiment. | Flores, Brady Joseph, Grace | Flores, Brady | Joseph, Grace | 1760 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_dls | |||||
| 2017-05-08 00:00:00 | Condensed Matter Physics | Josephson Junction | We use superconducting strips of niobium with an insulating separation layer to investigate the Josephson Effect across Josephson Junctions cooled to 4° K using a dewar and liquid helium. The characteristic plot of I vs V for a Josephson junction are created from measuring the potential across the junction while applying currents ranging from ±0.50 mA. Magnetic fields ranging from -7.95 to 7.08 gauss were applied via a solenoid to determine the flux quantum value experimentally. Magnetic field dependence was not seen, as well as non-characteristic Josephson effect I-V behavior, leading to the conclusion that a different weak-link structure was being examined. | Eix, Joe Yurs, Maxwell | Eix, Joe | Yurs, Maxwell | 1731 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_josephsonjunction | |||||
| 2017-05-08 00:00:00 | Optics | Quadrature Michelson Morley Interferometer | We construct a quadrature Michelson interferometer that improves on the standard Michelson interferometer by measuring direction as well as displacement. We demonstrate its use by also measuring the piezoelectric properties of quartz crystal. | White, Jarod | White, Jarod | 1751 | |||||||
| 2017-05-08 00:00:00 | Atomic Physics | Light Absorption of Amorphous/Nano-Crystalline Silicon | The absorption coefficient for thin, mixed phase amorphous and nanocrystalline silicon films was measured with the constant photocurrent method for photon energies between 1.1-2.1 eV. Data was collected for 8 samples of varying crystalline fraction. The absorption spectrum is analysed in order to compute the Urbach slope, a measure of disorder in the thin films. As predicted by theory, the disorder in the films decreases with an increase in nanocrystals. | Sundquist, Andrew | Sundquist, Andrew | 1741 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_lightabsorption | ||||||
| 2017-05-08 00:00:00 | Condensed Matter Physics | Magnetization Dependence of the Zero Magnetization State | The remagnetizing remanences of samples of VHS tape, Nickel wire, and Alnico have been measured following multiple different methods of demagnetization. These remanences were found to vary greatly, depending on the method used. The Stoner-Wohlfarth Model was able to predict this dependence for the VHS tape and Nickel wire, but not for the Alnico. Because remagnetizing remanence depends on preparation method, differences between predicted and observed behaviors of this remanence cannot always be attributed to magnetic interactions within the sample. This preparation dependence also means that researchers may need to specify the method used to demagnetize their samples for their results to be meaningful. | Hamann, Aaron Vogt, Ryan | Hamann. Aaron | Vogt, Ryan | 1732 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_zeromagnetizationstate | |||||
| 2017-05-08 00:00:00 | Cosmic Ray Experiments | Measuring Cosmic Ray Muon Momentum from Cherenkov Radiation | A nitrogen gas Cherenkov detector has been used to characterize the integral and differential spectra of cosmic ray muons in the 1.8 to 4.0 GeV/c momentum range. The detector was pressurized between 200 and 1000 kPa to produce the desired Cherenkov threshold momenta. The exponent in the power law that relates the rate of integral muon flux to the threshold momentum is determined to be -0.87 ± 0.05, consistent with past experimental results within 0.1 standard deviations. The accuracy of the differential spectrum is limited due to statistical fluctuations. The addition of an auxiliary scintillator paddle used to veto shower events is found to cause effects consistent with expectations and significantly improve the accuracy of this experiment. | Kampa, Cole Quinn, Ryan | Kampa, Cole | Quinn, Ryan | 1710 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_cherenkovradiation | |||||
| 2017-05-08 00:00:00 | Atomic Physics | Moessbauer Spectroscopy of Fe57 Compounds | Mossbauer spectroscopy was used to probe the hyperfine energy levels in Fe57 compounds. Due the to recoil free gamma ray absorptions and emissions of solids, the 10-9 eV hyperfine structure of these compounds' energy levels could be studied. By Doppler shifting gamma rays from a Co57 source, a spectrum of gamma rays was produced with 1 part in 1013 resolution, allowing the nuclear Zeeman effect, the isomer shift, and quadrupole splitting of Fe57 compounds to be measured. Using on a known calibration factor, we were able to achieve 10-9 eV precision, and our results ranged from 0.00-2.50 standard deviations from literature values, with the exception of a single 5.50 sigma event. Extensions of this work would include an attempt to measure the known calibration factor directly and to investigate the temperature dependence of these energy levels. | Fitz Axen, Margot Novotny, Jake | Fitz Axen, Margot | Novotny, Jake | 1742 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_moessbauerspectroscopy | |||||
| 2017-05-08 00:00:00 | Atomic Physics | Pulsed NMR of a Curing Epoxy | H-1 Pulsed Nuclear Magnetic Resonance was used to ‘watch’ epoxy cure. By using the spin-lattice T1 and spin-spin T2 relaxation times, the curing process was plotted as a function of time. T1 was found to increase from ~50 ms to ~67 ms over a time period of approximately 180 minutes, while T2 was found to increase from ~8 ms to ~27 ms over the same time period. T1 results are consistent with theory while T2 results contradict theory. | Schmidt, Ryder Sperle, Matthew | Schmidt, Ryder | Sperle, Matthew | 1743 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_nmr | |||||
| 2017-05-08 00:00:00 | Optics | Single Photon Quantum Interference and Mach Zehnder Interferometer | We demonstrate the existence of single photons and build a Mach-Zehnder interferometer with a quantum eraser. An anticorrelation parameter of alpha_ABB’ = 0.000 ± 0.003 was recorded, showing the presence of single photons, while the quantum eraser was not able to be completed. The interesting effects of quantized light, superposition, and information destruction are explored. | Francis, Benjamin Schubert-Sponsel, Robert | Francis, Benjamin | Schubert-Sponsel, Robert | 1752 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_spqimachzehdner | |||||
| 2017-05-08 00:00:00 | Atomic Physics | Enhancement of the Magneto-Optical Kerr Effect in Permalloy | We examine the longitudinal magneto-optic Kerr effect (MOKE) in thin permalloy films and attempt to enhance the strength of the MOKE signal using a glass prism. A sample placed within a magnetic field was probed using a 635 nm diode laser in order to measure the fractional Kerr signal. The measurement was repeated with a glass prism covering the sample. It was predicted that the prism would have the effect of approximately doubling the maximum strength of the signal. We obtained values that are within 1 standard deviation of what was predicted. The addition of the prism resulted in a smaller enhancement than expected at 49%. | Ehret, Kaitlin Lach, Mackenzie | Ehret, Kaitlin | Lach, Mackenzie | 1744 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_kerreffect | |||||
| 2017-05-08 00:00:00 | Condensed Matter Physics | Surface Plasmon Resonance | Surface plasmon resonance refers to resonant oscillations of electrons on an interface between an insulator and a conductor. Resonance can be stimulated by light incident on the interface that matches both the frequency and momentum of the interfacial wave. In this work, specific frequency-momentum pairs necessary to stimulate surface plasmon resonance were examined at a silver-air interface. Light at frequencies throughout the visible region was shone through a glass prism and onto this interface at a variety of incident angles. When the resonance conditions were met, the incident light transferred energy to the surface wave, driving oscillation; as a result, the reflected light wave decreased in intensity. This behavior allowed the resonance conditions of the silver-air interface to be examined and the dielectric function of silver in the visible region determined. The experimental frequency-wavevector pairs agreed quantitatively with literature values, but the dielectric functions found from these values revealed a systematic error. | Andersen, Molly Grindstaff, Jesse | Andersen, Molly | Grindstaff, Jesse | 1733 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_spr | |||||
| 2017-05-08 00:00:00 | Misc | Thermal Diffusion Imaging and Modelling of Heat Flux in Various Metals | The tip of a cylindrical steel rod was heated and brought into contact at the center of a metal plate. A thermal camera was then used to record the thermal diffusion taking place inside the metal. A computer program called, FLIR TOOLS, was then used to translate the recording, frame by frame, into an Excel Spreadsheet where each cell represents the temperature of each pixel of each frame. These temperatures were then used in an equation called, Gaussian Parameter, that when plotted against time gave a slope proportional to 8 times the thermal diffusivity. The thermal diffusivities for three different test metals were 62.7±1.5 mm^2/s for Aluminum Alloy, 34.7±0.7 mm^2/s for Brass, and 108.2±0.3 mm^2/s for Copper. | Dang, Charlie Troy, Tia | Dang, Charlie | Troy,Tia | 1790 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_thermaldiffusivity | |||||
| 2017-05-08 00:00:00 | Acoustics | Modeling a Driven Thermoacoustic Oscillator with the Adler Equation | A thermoacoustic oscillator was driven by a loudspeaker. Various aspects related to the synchronization of the system were measured and compared to a model based on the Adler equation. Initial results were unable to be reproduced, this lead to finding a correlation between the locking range and temperature. Further experimentation is required to confirm the Adler equation's ability to describe the thermoacoustic oscillator system. | Schee, Mikhail Steiner, Josef | Schee, Mikhail | Steiner, Josef | 1770 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_thermoacousticlaser | |||||
| 2017-05-08 00:00:00 | Optics | Young's Double Slit and Quantum Eraser | The wave particle duality nature of photons was observed using the Young’s double slit experiment. An incandescent light bulb with bandpass filter was used as a single photons light source. Interference pattern was formed in the double-slit experiment due to photon self-interference. Then, a which-path marker was added behind the double-slit to mark the photons with their polarization so that the information of which slit did the photons took exist. With the existence of which-path information, the interference was destroyed. A quantum eraser was then added to erase the which-path information and restoring the interference pattern. | Tan, Chiou Yang Tan, Xin Zhi | Tan, Chiou Yang | Tan, Xin Zhi | 1753 | https://sites.google.com/a/umn.edu/mxp/student-projects/2017_spring/s17_youngsdoubleslit | |||||
| 2016-05-09 00:00:00 | Misc | Analyzing a Vibrating Guitar String | High-speed video was taken of a guitar string fixed at its endpoints, and plucked at various dis- placements along its resting position. The video was deconstructed into frames, which were processed using ImageJ software to yield a scatterplot waveform in two spatial coordinates, such that each frame represents a different stage in the periodic motion of the string. The data was fit to 10-term Fourier series and the resulting coefficients were compared to theoretical predictions. The results showed a high level of correspondence between prediction and empirical results for low-amplitude displacements. High amplitude displacements resulted in larger deviations between theory and experiment, which were more pronounced with increasing modal number n. These results suggest that the linear model is a more reliable approximation for modes in which n remains small. | Denney, Andre Kimyon, Dawson | Denney, Andre | Kimyon, Dawson | 1690 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16guitarstring | |||||
| 2016-05-09 00:00:00 | BioPhysics | Applications for Fluorescence Correlation Spectroscopy | We observe the diffusion of Rhodamine 6G (R6G) and fluorescent nanospheres in aqueous solution by focusing a 532nm laser through an objective lens to create a 1 micrometer^3 observation volume. The laser excites the R6G molecules in this region, causing them to fluoresce. The photons released in this fluorescence pass through a confocal detection pinhole, which filters out light not originating from the specific observation volume, and are subsequently measured by a photomultiplier tube (PMT). The PMT is sensitive to single photons and outputs photon counts as TTL signal to the computer where the digital signal is processed. The data obtained is fluorescence intensity as a function of time. By auto-correlating this intensity data, we generate a correlation curve, from which the diffusion coefficient, concentration, and size of the molecules are determined. | Bruffey, Matthew Pahl, Anthony | Bruffey, Matthew | Pahl, Anthony | 1660 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_fcs | |||||
| 2016-05-09 00:00:00 | Acoustics | Measuring Young's Modulus Using a Magnetorestrictive Driver | By utilizing the ferromagnetic properties of nickel and the phenomenon of magnetostriction, the velocity of sound, and Young’s modulus were calculated for rods of three different materials, namely 6061 aluminum, PVC, and Maple wood. The results of this experiment yielded velocities of sound in meters per second for Al, PVC, and Maple as 4605±1607,1633±375,4733±379 respectively, and values of 57.3±40.0,3.71±1.7,13.4±2.1 GPa respectively for Young’s modulus. | Kavanaugh, Joseph Whittier, Devon | Kavanaugh, Joseph | Whittier, Devon | 1670 | ||||||
| 2016-05-09 00:00:00 | Misc | Detection and Extraction of Weak Signals Buried in Noise | We detected and extracted weak signals from noise by using the autoregressive (AR) model for a stationary, correlated process. The prediction of the noise pattern obtained in such a model was subtracted off the original noise-contaminated signal to recover the desired signal. This technique was applied to detect both signals in computer simulation and in an audio experiment. The result was satisfactory with root mean square error from the original signal of 0.153 in computer simulation and an R2 value of 0.82 from a least square linear fit to the original signal versus extracted signal plot in the audio experiment. Further improvements including exploring the effect of different types of noise on the efficiency of the AR model signal extraction technique and using autocorrelation matrix (Yule-Walker method) for larger data set could help us better understand the effectiveness and limitation of this technique and also extend the functionality of the current program. | Cai, Jingnan Callis, Keagan | Cai, Jingnan | Callis, Keagan | 1691 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_weaknoiseextraction | |||||
| 2016-05-09 00:00:00 | Optics | Exploration of the Ball-rod Physical System using an Optical Interferometer | The dynamics of a steel rod in a collision with a rigid body (steel ball) are examined, making use of a Michelson interferometer to perform accurate measurements of the position of the rod as a function of time. The effect of the compression wave on the motion of the rod introduced by the collision was observed and used to make a determination of Young’s modulus for steel. The velocity of the compression wave in the rod was measured 4938 m/s and Young’s modulus was calculated as E = 1.96 x 1011 N.m^-2 which both are consistent with literature values for steel. The end of the rod initially shows a motion in “start-and-stop” fashion, but this motion gets more complicated as the rod keeps moving. | Vahidi Azar, Nardin Ziegler, Andrew | Vahidi Azar, Nardin | Ziegler, Andrew | 1654 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_ballrodinterferometer | |||||
| 2016-05-09 00:00:00 | Condended Matter Physics | Josephson Junction | The purpose of this experiment was to measure the IV characteristics of a Josephson junction and to determine the critical current at zero magnetic field. This experiment also hoped to determine the magnetic flux quantum by analyzing the critical currents of the Josephson junction under a varying magnetic field. Two distinct values of the critical current were found in the absence of a magnetic field. These value were found to be (27.97 0.08) mA and (-34.19 0.08) mA. These were an extremely large number of (>1000) away from the expected value. The determination of the quantum flux was not successful as the “nodes” of the quantum interference patterns could not be resolved accurately. | Abid, Syed Kapeghian, Jesse | Abid, Syed | Kapeghian, Jesse | 1630 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_josephsonjunction | |||||
| 2016-05-09 00:00:00 | Condensed Matter Physics | Magnetic Reversions in Multi-segmented Nanowires | Halvorson, Catherine | Halvorson. Catherine | 1631 | ||||||||
| 2016-05-09 00:00:00 | Condensed Matter Physics | Measurement of the 4th Sound Velocity in an Annular Resonator | The temperature dependence of 4th sound of superfluid helium 4 in an annular resonator was observed. 4th sound is a pressure wave in the superfluid component of liquid helium 4 and can exist at temperatures below the lambda transition at 2.17 K. Transducers fixed to the resonator were used to excite and detect 4th sound waves. The driving frequency was adjusted to produce 4th sound standing waves, and the resonant frequencies used to determine the wave velocity. Resonant frequencies up to the 9th mode were resolved. The observed modes of 2nd order and higher failed to be integer multiples of the fundamental, suggesting non-uniform porosity of the aluminum oxide comprising the superleak. Measured velocity values deviated systematically from accepted values. | Molacek, Luke Spieker, Richard | Molacek, Luke | Spieker, Richard | 1632 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_fourthsound | |||||
| 2016-05-09 00:00:00 | Condensed Matter Physics | Measurement of the Superfluid Transition of He4 with a Vibrating Reed | We use a vibrating cantilever reed of stainless steel driven electrostatically with a fundamental resonant frequency of 4768.53 ± 0.02 Hz to observe the temperature at which liquid 4He undergoes a phase transition to a superfluid. This technique, similar in setup to that used to measure Young’s Modulus, accurately determines the transition temperature by analysis of the reed’s frequency of oscillation at a given temperature, influenced by the damping and inertial forces of the viscous fluid on the reed. We found the transition temperature to be 2.1705 ± 0.0005 K; this is 12.6 standard deviations from the expected value. | Schlenker, Lauren Schroeder, Neil | Schlenker, Lauren | Schroeder. Neil | 1633 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring | |||||
| 2016-05-09 00:00:00 | Cosmic Ray Experiments | Measuring Cosmic Ray Muon Momentum from Chrenkov Radiation | We use a carbon dioxide ¬based Cherenkov radiation detector to measure the integral flux of vertical cosmic ray muons in the momentum range of 1.4 GeV/c to 3.6 GeV/c. Sources for a possible over-detection of muons at these threshold momenta are investigated. The momentum distribution is fitted to a power law with a parameter value of a = - (1.02 ± 0.04)c/GeV . | Ahmad, Bilal Whitney, Michael | Ahmad, Bilal | Whitney, Michael | 1610 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_cherenkovradiation | |||||
| 2016-05-09 00:00:00 | Misc | Measuring the Instantaneous Distance to the Moon | Our experiment sought to determine the distance to the Moon from an observer on the Earth’s surface by measuring the change in angular size of the Moon disk over the course of several hours. From our data we found the Moon distance to be (1.40 ± 0.71) x 10^5km. As a byproduct of this measurement we could also determine the Moon radius and the radial velocity component of the Moon velocity. For the radius we found a value of 604.17±1.53 km and for the radial velocity (1.21± 8.9) x 10^-6 km/sec. The results we obtained for both the distance and the radius are both half of the known values for the distance and radius. | Morehouse, Scott Rush, Griffin | Morehouse, Scott | Rush, Griffin | 1692 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_moondistance | |||||
| 2016-05-09 00:00:00 | Optics | Measuring the Speed of Light via Beat Frequencies of a Laser's Longitudinal Modes | Using an open cavity Helium Neon gas laser with an adjustable cavity length, we measured the speed of light in air. By measuring the beat frequencies of the longitudinal modes as a function of cavity length, we measured cair = (2.9968 ± 0.0012)*10^8 m/s. This is consistent with literature values but not precise enough to distinguish the speed of light in a vacuum, which was a goal for the precision of the experiment.The theoretical limit for accuracy in this experiment is 1 part in 10,000 and our result was accurate to 1 part in 2,500. | Hank, Michael Sorrell, George | Hank, Michael | Sorrell, George | 1650 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_speedoflight | |||||
| 2016-05-09 00:00:00 | Optics | Mie Scattering | Light from a helium neon laser is scattered off of a suspension of micron-sized latex spheres and the scattered intensity is measured as a function of angle. The measured scattering intensity is fitted to a model using the theory of Mie scattering to determine the size of the spheres. The spheres are found to have a radius of 1.56 ± 0.03 micrometers, which varies from the manufacturer’s value of 1.50 micrometers by 2.0 standard deviations. | Freyermuth, Jacob Nagarajin, Vikram | Freyermuth, Jacob | Nagarajin, Vikram | 1651 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_miescattering | |||||
| 2016-05-09 00:00:00 | Misc | Molecular Dynamics Simulation of a Liquid Crystal in the Nematic Phase | A molecular dynamics simulation is conducted using the Gay-Berne potential and leapfrog integration. The goal of the project is to successfully simulate a liquid crystal in the nematic phase. Liquid crystal molecules which are anisotropic in shape will be modeled as ellipsoids. The nematic phaseis characterized by orientational ordering of the molecular axes. By using scientific visualization,a scalar order parameter, and the calculation of the radial distribution function, the fluid behavior and the nematic phase of the liquid crystal in the simulation will be confirmed. | Chem, Bryan | Chem, Bryan | 1693 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_liquidcrystalsimulation | ||||||
| 2016-05-09 00:00:00 | Atomic Physics | NMR Spectroscopy of Powdered Milk Components | A Teachspin PS2 spectrometer was used to measure the spin-lattice relaxation time, T1, and the spin-spin relaxation time, T2 of the nuclear magnetic resonance (NMR) signals of rehydrated powdered skim milk with various concentrations of lactose added. This was done in an attempt to distinguish the effects of the lactose and the protein in skim milk. The relaxation times of glycerol and water mixtures in different proportions were also measured, to observe the effect of viscosity on T1 and T2. Although we were unable to build a quantitative model for T1 and T2 values of the skim milk samples, we succeeded in measuring the relaxation constants for a variety of such samples. | Dregni, Aurelio Tiance, Xia | Dregni, Aurelio | Tiance, Xia | 1640 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_nmr | |||||
| 2016-05-09 00:00:00 | Misc | Radiation Damage to Plastic Scintillator | We use a photomultiplier tube to measure light output from plastic scintillator exposed to a Cesium 137 radiation source. Measurements are made for scintillators previously damaged with 10, 1.7, and 0 MRads of radiation. We compare intensity spectra of the three scintillators to observe the effect of radiation damage. The spectra are approximated as exponentials, and least square fits of the logs of the spectra are performed in order to measure the exponential decay constants. These constants are compared in an attempt to quantify the reduction in intensity. The reduction in light output is found to be non-uniform across all intensities, such that a finding quantitative number for the intensity reduction using this apparatus is not meaningful.The apparatus is found to be sufficient for qualitatively comparing relative radiation damage. | Bersch, Jeff Revering, Michael | Bersch, Jeff | Revering, Michael | 1695 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_radiationdamage | |||||
| 2016-05-09 00:00:00 | Atomic Physics | Vibrational Spectrum of N2 | We investigate the emission spectra of electronically excited diatomic nitrogen N2 within an AC capillary discharge tube. While exposing the gas to a large potential difference to induce metastable excited states the electro-magnetic radiation produced in the process of de-excitation was collected via fiber optic cable and acquired by a spectrometer interfaced to a PC. We determined mechanical constants of the diatomic nitrogen molecule for each excited electronic state, including the Hooke’s law force constants at equilibrium, the vibrational frequencies, and dissociation energies. | Chaffin, Jeffrey Schaefer, Adam | Chaffin, Jeffrey | Schaefer, Adam | 1641 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_spectraofn2 | |||||
| 2016-05-09 00:00:00 | Optics | Single Photon Quantum Interference | To demonstrate the quantum nature of light, a blue diode pump laser with a nonlinear crystal is used to create an entangled photon source. By placing a polarizing beam splitter in one of the entangled beam arms, a three-detector anticorrelation parameter alpha —the ratio of the coincidence rate to the accidental rate—is determined, where alpha < 1 (anticorrelated) implies the existence of photons. We measure an alpha = 0.009(3) proving photons by 330?. By adding a fourth detector and additional polarizing beam splitter to the other beam arm, a simpler version of Bell’s inequality is tested (Hardy’s test). By measuring coincidence probabilities between these four detectors, quantum mechanics is shown to violate our classical assumptions of local realism by 165 sigma. | Greavu, John Schlicht, Kyle | Greavu, John | Schlicht, Kyle | 1651 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_spqi | |||||
| 2016-05-09 00:00:00 | Atomic Physics | Doppler Free Saturated Absorption Spectroscopy | We report on the use of an external cavity diode laser (ECL) to measure the saturated absorption spectrum for the 5S1/2 -> 5P3/2 electronic transition in Rb85 and Rb87 Rubidium gas. This method eliminates Doppler broadening of spectral lines regardless of the thermal motions of individual atoms, allowing for quantitative measurements of hyperfine spectra and coupling constants, which has made it a technique often used in high precision measurements of fundamental constants. Temperature dependent Doppler Broadening is demonstrated, and both ground and excited state hyperfine structure is determined. | Sharkey, Benjamin Zheng, Jingyang | Sharkey, Benjamin | Zheng, Jingyang | 1642 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_saturatedabsorptionspectroscopy | |||||
| 2016-05-09 00:00:00 | Misc | Thermal Diffusion Imaging and Modeling of Heat Flux in Various Metals | In this experiment we observed how heat diffused in brass, copper, and aluminum and used this to calculate the thermal diffusivity of each metal. To do this we used a Flir C2 Thermal Imaging Camera and heated up a metal sheet of brass, copper, and aluminum using a metal rod. We found that the diffusion was well modeled using a Gaussian with the form T(r, t) proportional to e^((-2r^2)/(r^o2 +8at)) where T is the temperature, ro is the distance at which the Gaussian falls off by e^2, r is the radial distance in cylindrical coordinates, t is time, and a is the thermal diffusivity. Using this method we calculated the thermal diffusivity of 70/30 brass to be (27.7±4.1)x10^-6m^2/s which is 1.56 sigma away from the accepted value, the thermal diffusivity of pure copper to be (109±27)x10 ^6m^2/s which is 0.07 sigma away from the accepted value, and the thermal diffusivity of 6061 Aluminum to be (43.6±8.6)x10^-6m^2/s which is 2.36 sigma away from the accepted value. | Hergenrader, Jacob Ponzillo, Joseph | Hergrenrader, Jacob | Ponzillo, Joseph | 1693 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_thermaldiffusionimaging | |||||
| 2016-05-09 00:00:00 | Atomic Physics | EPR Spectroscopy | Rotational Correlation times of a spin probe placed in a series of mixtures of water and glycerol under varying concentration and temperature were measured using electron paramagnetic resonance (EPR) spectrometry. The rotational correlation time was used to make characteristic assumptions about the viscosities of the solutions used. | Iverson, Samual Molla, Kalkidan | Iverson, Samual | Molla, Kalkidan | 1642 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_epr | |||||
| 2016-05-09 00:00:00 | Misc | Use of Magnetite as Anode for Electrolysis of Water | We aimed to study the effects of anodic surface area on the efficiency with which electrolysis, performed using magnetite (Fe 3 O 4 ) anodes, produces chemical fuel in the form of H 2 . We developed magnetite anodes of differing surface areas and performed cyclic voltammogram tests, which measure current while sweeping voltage, to determine the potentials at which these anodes provide the most current. Following this, these currentoptimizing potentials were applied to their respective anodes and the produced current was measured as a function of time. These current measurements were then compared to determine if the surface area of the anode changes the current yielded from electrolysis. The trend seemed to have a positive correlation with surface area, but we were not able to directly measure the surface area, so there is some uncertainty in the relationship. 24 | Anderson, Bryan Kamal, Samantha | Anderson, Bryan | Kamal, Samantha | 1694 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_electrolysisofwater | |||||
| 2016-05-09 00:00:00 | Optics | Variable Spectral-Width, Wavelength Tuneable Light Source Using and SLD | We have built a variable spectral-width, wavelength-tunable light source using an Superluminescent Light Emitting Diode (SLD). This was done through the use of an external optical feedback cavity, which allows for easy adjustments or customizations. We obtained a 21.5mW laser with a usable power of 2.1mW. Our laser has a central wavelength of lambda = 838.8 ± 0.01nm and an operating wavelength range between 834 – 842nm. We measured the mode spacing between the longitudinal peaks to be constant, and delta_lambda = 0.342 ± 0.01nm. Using these calculations, we were able to obtain a cavity length inside the SLD of L = 294 ± 1micrometers. | Miller, Max Moua, David | Miller, Max | Moua, David | 1652 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_sld | |||||
| 2016-05-09 00:00:00 | Optics | Young's Double Slit Experiment with Single Photons and Quantum Eraser | Young’s renowned double slit experiment was performed at intensities low enough to demonstrate that the interference was solely due to single photons self interfering. The addition of orthogonal polarizers over each slit, or “which path” markers, destroyed the interference and produced the pattern of a single slit scenario. Lastly a quantum eraser was added, in an attempt to restore the interference pattern by removing the “which path” information. These results were inconclusive, and further experimentation is required to prove that it is possible. | Bren, Jesse Marek, Jeffrey | Bren, Jesse | Marek, Jeffrey | 1653 | https://sites.google.com/a/umn.edu/mxp/student-projects/2016-Spring/s16_youngsdoubleslit | |||||
| 2015-05-11 00:00:00 | BioPhysics | Actin Myosin Motility Assay | In vitro measurements were carried out using a high resolution video camera attached to a fluorescence microscope to determine the relationship between actin filament length and ATP concentration. The motor protein’s roles in muscle function were specifically investigated, and the optimal environment for actin polymerization was determined to be in AB buffer in a pH range of 7.0-8.0. The filament length dependence of actin on ATP was shown that in a good buffer, the higher ATP concentrations facilitated longer filament lengths. | Munns, Katie Vennemann, Thomas | Munns, Katie | Vennemann, Thomas | 1560 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15motilityassay | |||||
| 2015-05-11 00:00:00 | Misc | Analyzing a Vibrating Guitar String Using High-Speed Photography | The vibrational behavior of a guitar string was observed using high-speed photography and image processing. These observations were compared to a standing wave model rooted in Fourier analysis. Small amplitude oscillations were found to follow the model more closely than large amplitude oscillations, although both forms of oscillations were found to deviate significantly from the model after six to seven periods. Vibrations at smaller initial fractional plucking lengths were also found to follow the model more closely than fractional plucking lengths near the middle of the string. The decay of amplitude over time was also found to be proportional to the fundamental frequency of oscillation. | Mishra, Sanjeev Homstad, Jackson | Mishra, Sanjeev | Homstad, Jackson | 1592 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15vibratingstring | |||||
| 2015-05-11 00:00:00 | Condensed Matter Physics | Anomalous Hall Effect and Magnetic After-Effect | The Anomalous Hall Effect of a thin film of Cobalt Chrome alloy is used to measure its magnetization in an external magnetic field. The magnetic aftereffect, the relaxation of magnetization in a film to a lower energy state when an external field has been changed, can be mistaken as a source of magnetic noise. The magnetic noise is measured to have a power spectral density of 1/f and the magnetic aftereffect had no quantifiable effect on the underling noise. | Koltz, Clinton | Koltz, Clinton | 1530 | |||||||
| 2015-05-11 00:00:00 | BioPhysics | Applied Biophysical Applications for Fluctuation Correlation Spectroscopy | A florescence spectrometer was constructed with the goal of determining binding affinities of protein-ligand complexes, such as phalloidin and F-actin, via fluctuation correlation. The spectrometer was successfully aligned so as to excite the calibration dye, Rhodamine 6G, and pass the refined fluorescence beam to a photon counting head. Several difficulties, including sources of background light, deterioration rate of calibration samples, apparatus alignment, and challenges finding the sample focal point were encountered. In tandem, these issues barred goal achievement; however, acquisition of data from an outside experiment allowed for confirmation of calibration theory. It was determined for the data set provided that the effective volume of excitation was 0.28±0.13 fL, which is within a sigma from the provided value of 0.20 fL. This confirms that the theory herein is correct for calibration of the apparatus | Hogan, Levi Thompson, Blake | Hogan, Levi | Thompson, Blake | 1562 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15fluctuationcorrelationspectroscopy | |||||
| 2015-05-11 00:00:00 | Condensed Matter Physics | Effects of Surface Energy on Rubrene Crystallization | The correlation between the activation energy of crystallizing rubrene and the energy of the surface it was grown on was determined. Rubrene was grown on silicon substrates modified with different molecules in order to change its surface energy. This rubrene was then thermally annealed on the modified surfaces. It was determined that there is no correlation between the surface energy and activation energy of crystal growth. This knowledge is useful to further predict and eventually control the growth kinematics of crystalline organic semiconductors. | Phenicie, Christopher | Phenicie, Christopher | 1531 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15crystalsizedetermination | ||||||
| 2015-05-11 00:00:00 | Optics | Dynamic Light Scattering | The method of dynamic light scattering was used to examine the light scattered from 45° , 90° , and 135° angles with the aid of a mirror placed inside of a cuvette. By using a laser to illuminate a solution of polystyrene spheres suspended in water and analyzing the fluctuations in the intensity of the scattered light, the time constant could be measured and compared to a theoretical value. the experiment validated the use of the mirror for a 45° degree angle, but more work is needed to definitively confirm the use of the mirror when examining an angle of 135°. | Reichert, Martin Jarchow, Mark | Reichert, Martin | Jarchow, Mark | 1550 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15dynamiclightscattering | |||||
| 2015-05-11 00:00:00 | Atomic Physics | CO2 Leak Rate | This experiment is related to the Mu2e experiment, which is an experiment that seeks Charged Lepton Flavor Violation. 25000 Mylar straws filled with Ar and CO2 will be used to build the tracker to detect electrons produced by process. Straws’ walls are only about 15 micrometers thick so CO2 gas can permeate through the straws, while Ar can hardly leak from the straws. Because it is crucial to make the space outside the straws vacuum, the leak rate of CO2 from straws must be limited under 33×10-5 ccm/min. A theory about the leak rate is proposed in this report. In our experiment, the leak rate measurements at different pressures were performed and the CO2 permeation theory using Fick’s law was tested | Ke, Yan Han, Zhixian | Ke, Yan | Han, Zhixian | 1541 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15c02leakrate | |||||
| 2015-05-11 00:00:00 | Optics | Exploration of the Ball-Rod Physical System Using an Optical Interferometer | This experiment investigates collisions between a steel ball and steel rods of various lengths. The interference pattern created by the impact waves is observed and recorded. The rod is found to move forward by means of these compression waves, and the end of the rod is found to never move in the negative direction. | Coff, Benjamin Larsen, Aaron | Coff, Benjamin | Larsen, Aaron | 1551 | ||||||
| 2015-05-11 00:00:00 | Particle Physics | Investigating Edge Effects in Gamma-Ray Spectroscopy | The goal of this project was to investigate the effect the position of a gamma ray source relative to a detector crystal has on the measured spectra produced. A Monte Carlo simulation was written to predict these changes and be compared to the experimental data. The simulation predicted no measurable change in spectra dependent on the location of the source, except for changes in distance from the detector. The experimental data confirmed this, although the poor reliability of the detector limited the strength of conclusions made | Ahlgren, Aaron Haar, Kevin | Ahlgren, Aaron | Haar, Kevin | 1520 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15gammarayspectroscopy | |||||
| 2015-05-11 00:00:00 | Misc | General Relativity: Circular Orbits on Spandex | In this experiment we will be examining the near-circular orbits of spheres rolling on a cylindrically symmetric spandex fabric surface modeling the geometry of the Central Body Schwarzschild solution. This describes the General Relativistic prediction for such a system. The goal is to analyze orbits with energy loss. Exponential decay functions were implemented to fit the data acquired. | Landberg, Daniel Svetlik, Joseph | Landberg, Daniel | Svetlik, Joseph | 1590 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15generalrelativity | |||||
| 2015-05-11 00:00:00 | Optics | HeNe Gas Laser Physics | We studied the underlying properties of the amplification model and transverse Hermite-Gaussian mode of an open cavity Helium-Neon laser. The goal of this project was to better understand optical physics through the use of lasers. A glass slide outside the cavity of a Melles Griot Helium-Neon laser gain tube 05-LHB-670 reflects in an angle dependent manner and tunes the gain. The output power distribution as a function of the angle of the slide was measured. | Miller, Joshua Lee, Eng | Miller, Joshua | Lee, Eng | 1552 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15henelaser | |||||
| 2015-05-11 00:00:00 | BioPhysics | Holographic Microscopy of Colloidal Sphere | This experiment proposes to measure the diameter of a colloidal sphere suspended in water by observing its random motions in two dimensions through video microscopy. Statistical arguments will be used to confirm the motion as random and justify the use of the Einstein- Smoluchowski relation. This experiment can provide a basis for an expansion to holographic video microscopy allowing for the particles 3-dimensional position and Boltzmann’s constant to be determined. By measuring the root mean squared displacement of the particle over a period of a 90 seconds, and factoring in the viscosity and temperature of the water in which the particle is suspended, the colloidal sphere’s diameter was calculated to be 1.085±0.015 micrometers. | Clark, Adam Bruce | Clark, Adam Bruce | 1563 | |||||||
| 2015-05-11 00:00:00 | NonLinear Systems | Markov Chain Model to Extract Chaotic Dynamics from Chua's Circuit | Chua's Circuit is one of electronic circuits that shows chaotic behavior. Three dimensional data which has V_C1, V_C2 , and I_L components is collected from Chua's circuit. By changing the resistance of the resistor outside the Chua's component as a parameter, it is possible to measure the amplitude of V_C1 at each resistance. From the amplitude and resistance, a bifurcation diagram which is a period-doubling, a change from an N-point attractor to a 2N-point attractor, which occurs when the control parameter is changed can be drawn. The Universal Feigenbaum constant is about 4.669. Measured Feigenbaum constant is 4.36 ( 0.05) after three doublings. The error between the measured constant and universal constant is 6.62 %. | Yoon, Hahn Joo Hui, Pikmai | Yoon, Hahn Joo | Hui, Pikmai | 1580 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15chaoticcircuit | |||||
| 2015-05-11 00:00:00 | Cosmic Ray Experiments | Measuring Cosmic Ray Muon Momentum from Cherenkov Radiation | In this experiment we measured the momentum spectrum of muons generated by cosmic rays striking the earth’s upper atmosphere. In order to do this, we created a muon telescope that measures the Cherenkov radiation produced by the muons passing through a pressurized gas. The pressure of the gas was varied to change the threshold momentum required for the muon to produce the radiation. This process was executed for two different gasses, carbon dioxide and nitrogen. Using the peaks of the Cherenkov radiation, we were able to plot the integral intensity as a function of momentum to create the momentum spectrum for the muons. However, our results indicate that the momentum spectra of these muons was y=e^{((-4.5±.1)+(-.40±.05)x))} from the carbon dioxide, while the results from the nitrogen indicate y=e^{((-4.7±.1)+(-.45±.04)x))} , where y and x are the integral intensity and muon threshold momentum, respectively. The disparity may be the result of a systematic error found in the experimental set up that went unaccounted for. | Erickson, Daniel Cina, Alexander | Erickson, Daniel | Cina, Alexander | 1510 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15cherenkovradiation | |||||
| 2015-05-11 00:00:00 | Optics | Measuring the Speed of Light via Beat Frequencies of a Laser's Longitudinal Modes | The speed of light, c, is significant because it is a fundamental constant in physics. In this experiment the speed of light in air, c_air, from which c may be easily calculated, was measured by analyzing the beat signal between neighboring longitudinal modes of an adjustable open cavity Helium-Neon (HeNe) laser for various cavity lengths. We measured c_air to be (2.997±0.003) x 108 m/s, which is 0.1 sigma away from the accepted value of 2.997 x 108 m/s. Our result is accurate to 1 part in 1,000. | Ask, Kali Bittermann, Noah | Ask, Kali | Bittermann, Noah | 1553 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15speedoflight | |||||
| 2015-05-11 00:00:00 | Optics | Determining Particle Size Using Mie Scattering | We conduct an experiment based on the theory of Mie scattering to determine the size of four different sets of spherical particles with different diameters, each in the micron scale. A polarized 632.8-nm laser beam is aimed at a cuvette of water containing latex spheres. The resulting spherical diffraction pattern is observed by a photodiode and used with an analysis program to calculate the average size. The results show that Mie theory could correctly determine the size of 3-micron diameter and 9.7-micron diameter spheres to be 3.0 +/- 0.3 microns and 9.7 +/- 0.3 microns, respectively. | Faella, Joseph Amodeo, Samuel | Faella, Joseph | Amodeo, Samuel | 1554 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15miescattering | |||||
| 2015-05-11 00:00:00 | Particle Physics | Mossbauer Spectroscopy | Mossbauer spectroscopy was utilized to observe the hyperfine splittings of the 14.4keV nuclear transition of 57Fe, Fe2O3, and Fe3O4. A 57Co source was placed on a moving platform to induce a Doppler-Effect energy shift, and absorption of these x-rays at specific velocity was determined by observing local minima in the x-ray counts on the opposite side of the samples. Isomer shift, Quadrupoles splitting, and the Zeeman effect were observed for the three samples. | Bosch, Nathan Zacher, Jeffrey | Bosch, Nathan | Zacher, Jeffrey | 1521 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15mossbauerspectroscopy | |||||
| 2015-05-11 00:00:00 | BioPhysics | Protein Diffusion from a DNA Point Source | We use in vitro methods of transcription and translation on DNA attached to microbeads to measure the diffusion of Green Fluorescent Protein (GFP) with time-lapse fluorescence photography. The laws of diffusion are applied to the observed concentration distribution to calculate a diffusion coefficient for GFP of 41 ± 6 micrometer^2/s, which differs from the expected value by 7sigma. Also, the rate of protein production for the combined DNA on one microbead is calculated to be 64 ± 9 proteins/sec. | Engel, Alexander Wendt, Mitchell | Engel, Alexander | Wendt, Mitchell | 1561 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15proteindiffusion | |||||
| 2015-05-11 00:00:00 | Atomic Physics | Pulsed NMR | The purpose of our experiment was to explore the technique and application of pulsed nuclear magnetic resonance. To do so we introduced a pulsed radio frequency to target the hydrogen nuclei of a sample in a magnetic field to create excitation of the nuclear spin magnetization. The decay of this excitation toward an equilibrium state is described by two parameters known as the relaxation time constants T1 and T2, also known as the spin-lattice and spin-spin relaxation time. It is these times that are measured and analyzed for various concentrations of distilled water and glycerol. We found that these relaxation times range from T1, T2 values of 2:405±0:005s, 1:361±0:012s for 100% distilled water to 0:032±0:001s, 0:017±0:001s for 100% glycerol. | Greene, Kyle Thies, Kazmyn | Greene, Kyle | Thies, Kazmyn | 1540 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15nmr | |||||
| 2015-05-11 00:00:00 | Optics | Refractive Index Measurement by Prism Autocollimation | We use reflection of light through a fluid-filled prism to determine the refractive index of the fluid in the prism. This method yields refractive index measurements accurate to within 0.2%, which makes it sufficient to detect changes in refractive index of a sugar solution as the sugar is metabolized by yeast. Using refractive index measurements, the mass action law rate constant per unit yeast cell density is measured to be (1.7±0.7)x10^12(minutes*cells/mL)^-1, for Fleischman’s active dry yeast at 24 degrees Celsius. | Crocker, Kyle Duran, Henry | Crocker, Kyle | Duran, Henry | 1555 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15prismautocollimation | |||||
| 2015-05-11 00:00:00 | Misc | Speed of Sound in Bubbly Liquids | In this experiment, the speed of sound was measured for bubbly mixtures of gas and water at various gas fractions; the gases used were air and helium. This was achieved by using a hydrophone to observe standing wave frequencies in a large cylinder (a one-dimensional acoustic waveguide) containing water that was injected with gas bubbles. The speed of sound in a bubbly liquid mixture exhibits interesting behavior, described by Wood’s Equation, and varies with the gas volume fraction at low frequencies. The results agreed with the general behavior described by the theory, but there was a noticeable discrepancy in both cases. | Graham, Travis | Graham, Travis | 1591 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15speedofsound | ||||||
| 2015-05-11 00:00:00 | Optics | Single Photon Quantum Interference | We have examined the quantum nature of light by measuring the anti-correlation parameter, a, for which Quantum Theory predicts a>=0, but Semiclassical Theory gives a>=1. Our best result gives a=0.0278±0.0003, which violates the Semiclassical prediction by 3241 standard deviations. Then we show Quantum Mechanics violates local realism by measuring Bell-Clauser-Horne inequality. Our result gives H=0.21±0.02, which violates the inequality set by local realism by 10.5 standard deviations | Xu, DuoDuo Ge, Wenbo | Xu, DuoDuo | Ge, Wenbo | 1556 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15spqi | |||||
| 2015-05-11 00:00:00 | Condensed Matter Physics | Temperature Dependence of Fourth Sound in He | We intend to find the temperature dependence of fourth sound in He-II with a cylindrical resonator packed with fine powder near temperatures of 1.6K to 2.1K. The resonance frequency of fourth sound is detected by the transducer mounted on the resonator. The measured resonance frequency was used to calculate the velocity of the fourth sound at different temperatures. The values obtained in the experiment were compared to the accepted values, with the results agreeing to within 2.03% difference | Liu, Yijia Jones, Brendon | Liu, Yijia | Jones, Brendon | 1532 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15fourthsound | |||||
| 2015-05-11 00:00:00 | 1594 | Ultrasound Imaging | We determined the resolution of an ultrasound image from a single piezoelectric transducer. The transducer created an ultrasound signal that propagates through the object and reflects off internal and external boundaries. In order to transform the raw data into an image of a cross section, we needed to find the attenuation of the different materials the signal was passed through. We wrote a program in Labview to produce two dimensional images based on the timing and amplitude of the received reflection signals. Objects of known internal structure, called phantoms, were used to confirm the accuracy of our software. We found that the axial resolution is 0.8±0.1 mm and the lateral resolution is 2.0±0.2 mm | Payant, Andrew Swancutt, Alexandra | Payant, Andrew | Swancutt, Alexandra | 1594 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15ultrasound | |||||
| 2015-05-11 00:00:00 | Misc | Using a Split-Ring Resonator to Measure Electromagnetic Properties of Liquids | We measured the resonance frequency and quality factor of a split-ring resonator when it was suspended in air, water, and aqueous solutions of NaCl of various concentrations. From this data, we determined the real and complex permittivity of water and observed the qualitative effects of NaCl concentration on the quality factor and resonance frequency of the split-ring resonator. The real part of permittivity was found to be 77.74 ± 0.01, agreeing within 1 sigma of the predicted 77.71. The imaginary permittivity was over 100 sigma from a literature extrapolation. The dependance of quality factor on saline concentration followed our prediction qualitatively, but not quantitatively | Bosch, David Bosch, Melissa | Bosch, David | Bosch, Melissa | 1593 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15splitcylinderresonators | |||||
| 2015-05-11 00:00:00 | Optics | Variable Spectral-Width, Wavelength-Tunable Light Source using an SLD | The goal of this project was to develop a tunable light source with a monochromatic output by coupling a superluminescent diode, with center wave length of 830 nm and bandwidth of 30 nm, and a diffraction grating to make an external optical feedback cavity. By developing this our group has effectively made multiple laser sources in one cavity. The results from the tunable light source showed a mode spacing of 0.35 nm measured over a range of 20 nm. From this measurement it was calculated that the cavity length of the SLD is 281.09 micrometers | DeMars, Luke Tilseth, Erik | DeMars, Luke | Tilseth, Erik | 1557 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15sld | |||||
| 2015-05-11 00:00:00 | Optics | Young's Double Slit Experiment with Quantum Eraser | We observed the particle/wave duality of single photons using a double slit experiment. An incandescent bulb passing light through a band-pass filter and a single slit creates a horizontal plane wave incident upon a double slit. A photomultiplier tube (PMT) translating across the diffraction envelope recorded the resulting photon self- interference pattern. Polarizers were then used to mark the photon passing through the slits, providing which-path information and eliminating photon self-interference. Finally, the addition of another polarizer destroyed the which-path information and partially restored the photon self-interference pattern. | Therneau, Joel Schoder, David | Therneau, Joel | Schoder, David | 1558 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15thermoacousitoscillator | |||||
| 2015-05-11 00:00:00 | Acoustics | Synchronization of a Thermoacoustic Oscillator with Periodic Audio Sources | An experiment capable of synchronizing a thermoacoustic oscillator with an external sinusoidal sound source was designed and conducted in such a way to collect automated, reproducible data over a large period of time. The methods employed were used to observe and measure the synchronization regions of the two devices. The regions measured compare to a theoretical model obeying the Adler equation in which an oscillator weakly couples to an external force. In addition to that, a brief exploration into the synchronization of a thermoacoustic oscillator with a non-sinusoidal, periodic external force was conducted in which synchronization was observed using signals driven by both triangle and square waves. The results from this experiment have laid a solid foundation that provides direction for further investigation into the synchronization characteristics of such devices. | Medved, Alexander Malcolm, Bron | Medved, Alexander | Malcolm, Bron | 1570 | https://sites.google.com/a/umn.edu/mxp/student-projects/2015---spring/s15thermoacousitoscillator | |||||
| 2014-05-09 00:00:00 | Acoustic | Change in Reverberation Due to Acoustic Damping | We characterized the reverberation of an aperiodic transient sound in a closed box, both with and without acoustic dampening material, and in a lecture hall in Tate Lab. Results were compared to relevant theory and related empirical data. We predicted that the acoustic dampening material would yield a steeper exponential curve in the output waveform’s decay as a function of time, and hence, a shorter reverberation time. We also predicted that lower input frequencies would yield longer reverberation times. Our results confirmed both predictions, and we also found in our Fourier transforms for the padded box and lecture hall that higher frequencies are absorbed more easily than lower frequencies. In addition, we found that our padding material shortened the reverberation times across all input frequencies used in this experiment to nearly the same value, an average of (1.327 ±0.133 )* 10^-4 seconds, although the values followed the pattern of decreasing as the input decreased; it’s just that the change in value was minute. | Forester, Beljeanne Hoseth, Jacquelyn | Forester, Beljeanne | Hoseth, Jacquelyn | 1470 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14reverberationtime | ||||
| 2014-05-09 00:00:00 | Optics | Diffuse Optical Tomography | Diffuse optical tomography was used to image an object, such that its size, shape, and location could be determined. The absorption coefficient of an object in a turbid medium measured at various depths was analyzed so it could be determined at what depths the size and shape of the object could be determined within 5% accuracy. This would simulate how far into body tissue doctors would be able to detect tumors or blood clots. | Albert, Lauren Perrine, Natalie | Albert, Lauren | Perrine, Natalie | 1450 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14diffuseopticaltomography | ||||
| 2014-05-09 00:00:00 | BioPhysics | DNA Replication Rate by Phi29 Polymerase | Phi29 polymerase is a molecular motor that participates in the replication of certain viral DNAs by attaching complementary base pairs to the growing polymer. Determining the rate that it proceeds along a double-stranded DNA molecule is an important measure of the polymerase’s conversion of chemical energy into mechanical work. In this experiment we made a preliminary measurement of the reaction conditions necessary for a subsequent rate determination, namely the viscosity of the fluid in which the replication reaction takes place. Using measurements of the Brownian motion of suspended beads, we determined the viscosity of the fluid to be (0.73 ± 0.06) mPa•s, 1.17 sigma below the accepted value of 0.80 mPa•s for pure water. | Joseph , Michael Matzke, Jared | Joseph , Michael | Matzke, Jared | 1460 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14dnaflowstrechingmicroscope | ||||
| 2014-05-09 00:00:00 | Misc | Effects of External Magnetic Field on Abrupt Contraction Flow in Ferrofluid | The volumetric flow rate of a ferrofluid is measured under varying magnetic field strength, from zero to 1000 Gauss. The experiment is conducted under three different excess pressure drops of 0, 6.9 and 10.3 kPa. The rheological response of ferrofluids in contraction and expansion flows is examined when a magnetic field is applied longitudinal. It is observed that the pressure, needed to produce the flowing of the ferrofluid, is proportional to the applied magnetic field. | Madden, Ryan McDonald, John | Madden, Ryan | McDonald, John | 1490 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14mrfluid | ||||
| 2014-05-09 00:00:00 | Cosmic Ray Experiments | Gamma Spectroscopy of Environmental Water Samples | This experiment looked to find the gamma spectroscopy of environmental water samples using a High-Purity Germanium detector. The samples that were used were tap water and water from the Mississippi river. The techniques that were used are based on a paper that was published in the American Journal of Physics by P.B. Siegel. There was not enough data from the water samples to be fitted so the activity of the radioactive isotopes in the samples could not be found. | Rasmusen, Cassandra Glasenapp, Samuel | Rasmusen, Cassandra | Glasenapp, Samuel | 1410 | File Cabinet | n/a | ||||
| 2014-05-09 00:00:00 | Condensed Matter Physics | Investigation of the Temperature Dependence of Relative Superfluid Density in Helium-4 | Pressure oscillations were induced in liquid helium at various temperatures below 2.17 Kelvin across a super leak membrane in a dual-chambered resonation cell. The frequency at which Helmholtz resonance occurred was then converted into a relative superfluid density and compared to empirical data. | Jarecki, Alex Traczyk, Alan | Jarecki, Alex | Traczyk, Alan | 1430 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14helmholtzresonator | ||||
| 2014-05-09 00:00:00 | Optics | Measuring Young’s Modulus in an Aluminum bar Using the Double Exposure Technique | We measure the Young’s Modulus of an aluminum bar by using holographic interferometry at different applied weights. Holographic interferometry can be used in the testing of stress and strain evaluation of a material. This will allow us to measure the distance, Delta y, created by the disturbance of the force applied to the aluminum bar. Our final results come to be about (621 ± 1.7) GPa for 2g and (1533±1.7) GPa for 100g compared to the accepted value, 69GPa. We are over by 8 sigma and 21 sigma respectively. | Chen , Cong Thao, Gina | Chen , Cong | Thao, Gina | 1452 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14holographicinterferometry | ||||
| 2014-05-09 00:00:00 | Condensed Matter Physics | Indirect Electron Tunneling | In this experiment, the energy of the phonon released during indirect electron tunneling of a germanium diode was measured and compared to previous experiments to determine its wave characteristics. This was accomplished by taking electronically differentiated I-V curves of the diodes at room temperature and at liquid helium temperature. The second derivative of the current revealed a peak at the phonon’s resonance energy when tested at the lower temperature range. A peak in the second derivative of the current was found at 7.3 0.4 meV and the peak showed a (chi_r)^2 of 0.92. The voltage that the peak was found at corresponds to (1.8± 0.1)*10^12 Hz, which characterizes a transverse acoustic (TA) wave and deviates by 1.5 sigma from the previously determined value of 1.95 *10^12 Hz. | Bakalov,Artem Bies,Jeffrey | Bakalov,Artem | Bies,Jeffrey | 1438 | File Cabinet | n/a | ||||
| 2014-05-09 00:00:00 | Condensed Matter Physics | Investigation of Thermoelectric Generators | This experiment investigates the thermoelectric figure of merit for two thermoelectric generators that contain Bismuth Telluride (Bi2Te3) and Bismuth Tin (BiSn), respectively. The figure of merit describes the ability of a given material to effectively produce thermoelectric power and is determined by obtaining the Seebeck coefficient and investigating the thermal and electrical conductivity for each of the thermoelectric generators. The Bismuth Telluride thermoelectric generator yields a figure of merit of (4.56±0.38)*10^-4, and the Bismuth Tin yields a value of (6.47±0.43)*10^-4. | Bock, Ethan Herrera, Marcelo | Bock, Ethan | Herrera, Marcelo | 1431 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14thermoelectricgenerators | ||||
| 2014-05-09 00:00:00 | BioPhysics | Measuring the Change in Viscosity of Artificial Cytoplasm due to DNA Replication | The viscosity of an artificial cytoplasm was measured by monitoring the Brownian motion of suspended spherical microparticles. A value of 1.609±.029 mPa•s was obtained. The change in viscosity over time was then measured after backteriophage DNA was added to the cytoplasm and allowed to replicate. No change in viscosity was measured, as DNA was observed to flocculate. | Antos , Blake Rush, Michael | Antos , Blake | Rush, Michael | 1461 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14fluidpropertiesofartificialcytoplasm | ||||
| 2014-05-09 00:00:00 | Cosmic Ray Experiments | Measuring the Momentum Distribution of Cosmic Ray Muon. | This experiment used a carbon-dioxide based Cherenkov detector to measure the integral flux of vertical muons in the momentum range of 3.5 to 1 GeV/c. The data was fit to an exponential curve, with a coefficient of 0.0108±0.0004 muons per second per cm^2 per sr and an exponent of -0.62±0.02. | Fischer, Will Thomas , Ryan | Fischer, Will | Thomas , Ryan | 1411 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14cherenkovradiation | ||||
| 2014-05-09 00:00:00 | Optics | Measuring the Speed of Light in Air Utilizing Longituninal Modes in an Adjustable-Length, Open-Cavity, HeNe Laser | This experiment used the properties of an adjustable length, open-cavity, HeNe laser to measure the speed of light in air. The speed of light in air was calculated by measuring the beat frequency between the laser's adjacent longitudinal modes. The calculated value was c_air = (2.99696 ± 0.00086) ×10^8 m/s. This result is off from the accepted value of 2.997125×10^8 m/s by 0.19 sigma, and is accurate to 1 part in 4,000. The likelihood of getting a result deviating by 0.19 sigma or more from the accepted value is 85%. | Gburek, Tim McSavaney, Matthew | Gburek, Tim | McSavaney, Matthew | 1458 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14measuringthespeedoflight | ||||
| 2014-05-09 00:00:00 | Optics | Measuring Fluid Viscosity Using Dynamic Light Scattering | We sought to use Dynamic Light Scattering, typically used for particle sizing, as way a to measure the dynamic viscosity of a fluid in which polystyrene spheres of known size were suspended. The viscosity was found by measuring the intensity fluctuations of light scattered by the spheres as they underwent Brownian Motion. By analyzing the intensity spectrum, the diffusion coefficient was found and then applied to the Stokes-Einstein relation to calculate the viscosity. We calculated the viscosity of five different fluids: Water, Methanol, 2-Propanol, a 10% Glycerin-Water Solution, and a 40% Glycerin-Water Solution. The calculated viscosities were: 0.731 ± .029 cP, 0.548 ± .011 cP, 1.946 ± .066 cP, 1.177 ± .022 cP, and 3.096 ± .061 cP, respectively. The deviations of these values from the literature were 4.07 sigma, 1.99 sigma, 1.90 sigma, 1.63 sigma, and 0.76 sigma, respectively. | Booth, Kevin Van Goor, Ethan | Booth, Kevin | Van Goor, Ethan | 1451 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14temperaturedependenceofnanosizedpolystrenespheres | ||||
| 2014-05-09 00:00:00 | BioPhysics | Comparing Optical Trap Stiffness Measurement Methods | The stiffness of an optical trap was calculated from the Brownian motion and Stoke’s flow methods. The trap stiffness from the Brownian motion method was measured to be 3.34(±1.33)x10^-8 N/m, and the stiffness from the Stoke’s flow method was measured to be 2.00(±0.95)x10^-8 N/m. An independent-sample z-test concluded at 95% confidence that both methods resulted in similar stiffness measurements. However, the Brownian motion method yielded more precise stiffness values. | Ravishankar, Adarsh Thor, Shengshee | Ravishankar, Adarsh | Thor, Shengshee | 1462 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14opticaltweezers | ||||
| 2014-05-09 00:00:00 | Particle Experiments | Mössbauer Spectroscopy | We have utilized the high precision Mössbauer spectroscopy and measured from iron and some iron oxides three types of hyperfine effects, namely the isomer shift, the nuclear Zeeman splitting and the quadrupole splitting. | Cheng, Yihong Zhang, Kai | Cheng, Yihong | Zhang, Kai | 1421 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14moessbauerspectroscopy | ||||
| 2014-05-09 00:00:00 | Cosmic Ray Experiments | Muon Speed measurement | The velocities of high energy atmospheric muons from particle cascades caused by cosmic ray collisions were measured by the use of multiple scintillator panels, and timing differences were determined between events in each plate. The results were (3.077±0.186)x10^8 m/s, which is about 0.5 sigma away from the expected value of approximately 99.4% of light speed. | Hart, Ezra Norris,Weston | Hart, Ezra | Norris,Weston | 1412 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14muonspeedmeasurement | ||||
| 2014-05-09 00:00:00 | Condensed Matter Physics | NMR | The spin-lattice relaxation time and spin-spin relaxation time of protons in solution of paramagnetic ion (copper sulfate) were measured by using pulsed NMR. The relaxation time was plotted as a function of concentration. A linear relationship in logarithmic scale is obtained. | Li, Qiushi Li, Shuo | Li, Qiushi | Li, Shuo | 1437 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14nmr | ||||
| 2014-05-09 00:00:00 | Optics | Properites of Helium Neon Lasers | We studied the properties of an open cavity helium-neon laser including the laser amplification model parameters, transverse Hermite-Gaussian mode beating, oscillation at 640.1nm, and spontaneous emission from the gain medium. Experimental results are compared to theoretical laser models and to typical helium neon laser parameters. | Hansen, Aaron Nelson-Linnell, Ian | Hansen, Aaron | Nelson-Linnell, Ian | 1453 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14propertiesofhenelasers | ||||
| 2014-05-09 00:00:00 | Particle Experiments | Raman Scattering Microscope | In this project we attempt to make a simple Raman spectrometer from non-specialized equipment. It was found that the spectrometer produces noise a factor of 10^5 times greater than the expected signal. Data was taken with a dedicated confocal Raman microscope for three minerals and their spectrums were found to all be correct within 1 sigma with the exception of two peaks in fluorapatite (1031.8 ± 4.5 cm^-1, off by 1.82 sigma and 1061.3± 4.5 cm^-1, off by 2.29 sigma) and one peak in calcite (159.58± 4.5 cm^-1, off by 1.24 sigma) | Mackenzie, Jasmine | Mackenzie, Jasmine | 1420 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14ramanscattering | |||||
| 2014-05-09 00:00:00 | Optics | Single Photon Quantum Interference | We show that light is composed of single photons by carrying out a correlation experiment exploiting Spontaneous Parametric Down-Conversion using Type-I BBO crystal. Our best result violates classical prediction of wave-like behavior for light by 74 standard deviations | Khan, Asad Nguyen, Quynh | Khan, Asad | Nguyen, Quynh | 1454 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14singlephotonquantuminterference | ||||
| 2014-05-09 00:00:00 | Optics | Young's Double Slit Experiment | We test the interference of photons through a double slit screen. The loss of interference is tested by inserting which-way polarizers in front of the slits, and we tested the restoration of interference in delayed choice experiment by the addition of a quantum-eraser. Prior experiments have used collimated beam intensities low enough to ensure that only one photon passes through the slits at one time. The which-way polarizers eliminated the interference fringes and displayed diffraction like behavior. The addition of the quantum eraser restored the interference fringes. | Buscher, Benjamin Cheng, Alison | Buscher, Benjamin | Cheng, Alison | 1455 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14youngsdoubleslit | ||||
| 2014-05-09 00:00:00 | Condensed Matter Physics | Temperature Dependence of the Speed of Second Sound in Helium II | In this experiment, the temperature dependence of the speed of second sound in He-II was observed by mechanically producing temperature harmonics in a brass cylindrical cavity near temperatures of ~ 1.56 – 2.17 degrees Kelvin. It was found that longitudinal modes of resonance were indeed observed at twelve temperatures and a quantitative temperature dependence was obtained for the speed of second sound. | Codoluto, Dan Dykhoff, Devin | Codoluto, Dan | Dykhoff, Devin | 1435 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14speedofsecondsound | ||||
| 2014-05-09 00:00:00 | Condensed Matter Physics | Spin Noise Spectroscopy in K and Rb | At equilibrium, a gas of atoms will experience random fluctuations in its magnetization. Probing the gas and measuring the spectrum of this spin noise provides a novel, non-perturbative method for determining atomic properties of the gas. The theory and expected values for the atomic properties of both Rb and K are covered in detail. Comparisons between the expected values of energy splittings in both Rb and K are made to experimental data. | Heinonen, Robin Krueger, Nick | Heinonen, Robin | Krueger, Nick | 1436 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14spinnoisespectroscopy | ||||
| 2014-05-09 00:00:00 | Cosmic Ray Experiments | Study of Time Dilation through Muon Decay Lifetimes | This experiment seeks to determine the effects of time dilation through the study of muon detection rates at varying atmospheric depths. Balloon borne Geiger tube systems logged muon detections from a depth of 1030g/cm^2 to 10g/cm^2 aboard a high-altitude balloon flight. The resulting flux counts were exponentially fit to extract an average muon decay lifetime of: (2.19 ± 0.0366)*10^-6 . This value is 0.2 sigma off of the globally accepted value of (2.197034 ± 0.000021)*10^-6 . The gamma factor necessary to obtain this value was 11.19, which implied an average measured muon velocity of 0.996c. | Carlon,Robert Corgan,David | Carlon,Robert | Corgan,David | 1413 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14timedilation | ||||
| 2014-05-09 00:00:00 | Condensed Matter Physics | Temperature Dependence of a Doped Semiconductor and Measuring the Hall Effect | We measured the temperature dependence of the conductivity and mobility of a silicon sample doped with boron in the range of 77 K to 200 K. The conductivity was supposed to fall as T^-2.2, and our data showed a curve of T^(-1.99±0.01), which is 21 sigma away from the expected value. Our mobility data followed the curve of T^(-1.45±0.04) , compared to the expected T^(-3/2) , which is 1.25 sigma away. | Bryan,Daniel Ganser,Kaylee | Bryan,Daniel | Ganser,Kaylee | 1432 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14halleffect | ||||
| 2014-05-09 00:00:00 | Condensed Matter Physics | Testing the Quantized Nature of Conductance | We worked to measure and characterize the quantum nature of electrical conductance in gold nanowires stretched to atomic diameters. We expected to see a relationship such that the conductance was in discrete multiples of G=2*n*e^2/h where n=2*w*/lambda. Our results show that for expected quantum numbers of n=1,2and 3 our experimental data was .99 +/- 1.52x10^-4, 1.84 +/- 2.53x10^-4 and 3.03 +/- 4.23x10^-4 which were off by 53.5, 625.1 and 74.3 sigma respectively | Ishokv, Ivan Richardson,Kenneth | Ishokv, Ivan | Richardson,Kenneth | 1433 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14quantizednatureofconductance | ||||
| 2014-05-09 00:00:00 | Condensed Matter Physics | Thermal Conductance as a Function of Applied Force at Copper-Copper Junctions | We report measurements of the relationship between thermal contact conductance and applied torque on a bolt compressing a copper-copper junction at 77K. Our data indicate a linear relationship between thermal contact conductance and applied torque of h_s = (410+-10)N + (3150+-90), for h_s in W m-2 K-1 and N in in-lb. Instrument limit error on diode voltage measurements generated low p values in linear regressions of thermal contact conductance, and a more precise multimeter and more frequent measurements would reduce uncertainty significantly. | Hank,Jonathon Ihde,Benjamin | Hank,Jonathon | Ihde,Benjamin | 1434 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2014---spring/s14thermalconductivity | ||||
| 2013-05-10 00:00:00 | Particle Experiments | Angular Correlation of Gamma Rays from Cobalt 60 | The angular correlation of successive gamma-rays emitted from a single nucleus in the decay chain of 60Co was studied using two scintillation detectors. The experimental data was compared to the angular correlation functions derived by Hamilton to confirm the j=4 2 0 quadrupole-quadrupole transition of the excited 60Ni nucleus. The experimentally determined coefficients in the angular correlation function were determined to be a1 = 0.114 ± 0.041 and a2 = 0.061 ± 0.039. These values are 0.27 and 0.49 sigma away respectively from the predicted values of 0.125 and 0.0417 and are consistent with theory. | Tanner Lange, Carrie Pfeifer | Tanner Lange | Carrie Pfeifer | n/a | 1320 | n/a | File Cabinet | n/a | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13angularcorrelationofgammaraysfromcobalt60 | n/a |
| 2013-05-10 00:00:00 | Optics | Measuring the Speed of Light using a Helium Neon Laser | Using Helium Neon, HeNe, laser with an adjustable cavity length, measurements of the speed of light through air will be taken. By lengthening the lasing cavity, the beat frequency of the differing modes under the laser gain curve will decrease. The speed of light can be measured as a function of the slope of the linear fit of the cavity length versus the inverse of this beat frequency. This experiment yielded the speed of light to be 2.99758±0.00072 x 10^8 m/s compared to the accepted value of 2.99792 x 10^8 m/s. | Chick, Will Klein, Matthew | Chick, Will | Klein, Matthew | 1355 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13speedlightlaser | ||||
| 2013-05-10 00:00:00 | Acoustic | Acoustic Bandgap in a Periodic Waveguide | A justification for describing the propagation of an acoustic wave in a periodic waveguide as a Bloch wave is given. It is shown, given a Bloch wave propagating in a periodic waveguide, that there are frequency ranges in which the acoustic wave effectively cannot propagate. A periodic waveguide is built to test the validity of these theoretical conclusions. Just like in the theory, the experimental data shows three distinct frequency bands in which the wave does not propagate, however, the boundaries of these regions and their magnitudes are significantly different than theory. Given the limitations of the equipment, it is concluded that this does not represent compelling evidence that the Bloch wave construction is false. | Andrew White Yinchuan Yu | Andrew White | Yinchuan Yu | 1370 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13acousticbandgapinaperiodicwaveguide | ||||
| 2013-05-10 00:00:00 | Optics | Brownian Motion of Ellipsoidal Particles | The rotational and translational Brownian motion of microscopic ellipsoidal particles in two dimensions was studied using video microscopy. The qualitative trends in the position and orientation of the particle versus time, the displacement in the position and orientation of the particle versus time, and the distributions the sizes of the displacements were found to agree with theory. Two methods were used to quantify the agreement of experimental results with theory by estimating Boltzmann's constant. The best estimate differed from theory by 0.03sigma, while the worst differed by -6.63sigma. The quality of the quantitative data is questionable, however, due to a lack of precision in the experiment and the possible presence of a number of systematic errors. | Freund, Ben Trebesch, Noah | Freund, Ben | Trebesch, Noah | 1350 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13brownianmotion | ||||
| 2013-05-10 00:00:00 | Cosmic Ray Experiments | Chaotic Dynamics in a Driven Spring-Pendulum System | The behavior of a driven spring-pendulum system was analyzed by plotting a bifurcation diagram of the chaotic and periodic regimes according to driving amplitude and frequency. Lyapunov exponents were found along the boundary between these regimes. All results were compared with numerical simulations based on theoretical models. For the case presented in this paper, the Lyapunov exponent was found to be 0.226±0.008 s^-1. | Marino, Joseph Nolting, Chris | Marino, Joseph | Nolting, Chris | 1310 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13chaoticspring | ||||
| 2013-05-10 00:00:00 | Misc | Characterization of a Gamma Lead Shield for a test Cryostat | We statistically analyzed the efficiency of a Gamma Lead Shield for a test cryostat. This allowed us to predict the usefulness of the Gamma Lead Shield. The background measurements in conjunction with 133Ba and 241Am sources were used to statistically analyze the ratio of rejected events with and without the shield. The source position and the detector were same throughout the experiment in order to minimize systematics. The rejection ratio as a function of energy is determined to be [(0.5689 ± 0.0591) + (-0.000842 ± 0.000256) x_keV]. | Codoreanu, Gheorghe Jaidye, Nafiz | Codoreanu, Alex | Jaidye, Nafiz | 1390 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13characterizationofgammashieldforthek100dilutionrefrigerator | ||||
| 2013-05-10 00:00:00 | Misc | Determining the Temperature of the Sun's Photosphere Using the H_beta Line | The temperature of the Sun's photosphere was measured without making any black- body assumptions. The technique used relied on measuring the equivalent width of the H-beta line. This measurement was carried out using a spectrometer with a resolution of 3.22Å. This measurement was compared to an empirical plot of equivalent width versus temperature. We expected to find an equivalent width of 3.68Å, corresponding to the accepted photospheric temperature of 5780K. We found an equivalent width of 4.63±0.3Å, which corresponds to a temperature of 6200 ± 850 K. | Mass, Zachary McLaughlin, Michael | Mass, Zachary | McLaughlin, Michael | 1391 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13chemicalcompositionandtemperatureofthesun | ||||
| 2013-05-10 00:00:00 | Optics | Diffuse Optical Tomography | Our goal for the experiment was to better understand the relationship between concentration and attenuation constant of a diffusive turbid medium. Later we will use this knowledge to measure the physical dimension (radius) of a solid object using diffuse optical tomography. We measured relationship of attenuation constant and concentration was µ/c=1.4352 ± 0.0831. We also measure the radius of an object inside a diffusive medium to be 1.6±0.224 cm which was 2.67sigma away from our expected value. | Ahmed, Ishtiaque McDonald, Jonathan | Ahmed, Ishtiaque | McDonald, Jonathan | 1351 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13diffuseopticaltomography | ||||
| 2013-05-10 00:00:00 | Condensed Matter Physics | Electrical Detection Of Ferromagnetic Resonance | We performed detection of ferromagnetic resonance in Fe/GaAs thin films by measuring DC voltage across the sample as it is placed in a static magnetic field and microwave radiation. Resonance is detected over Xband (8-11GHz) microwave frequencies, with the sample oriented at two different angles with respect to the static field applied. The experimental setup is based on a previous MXP project. The measured resonance frequency is compared with theoretical results and used to give a rough estimate of anisotropic contants. The analysis shows that the sample used demonstrate strong uniaxial anisotropy and weak cubic anisotropy. Gilbert damping parameter alpha_G of the resonance detected is 7.21±0.18, within the accepted range, which indicates that what is detected is a real resonance. | Ge, Yang Xiao, Yang | Ge, Yang | Xiao, Yang | 1330 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13fmr | ||||
| 2013-05-10 00:00:00 | Misc | Inductive-Capacitive Resonance Shifting of Split-Ring Resonators for Biosensing Applications | For this research project, we measure the shift in the fundamental resonance frequency for a Split-Ring Resonator SRR experiencing a change in its environment. When terahertz THz radiation is incident normal to the plane of the SRR, it is observed to resonate due to its fundamental inductive-capacitance LC frequency. The LC frequency was measured to be around 0.4THz, both experimentally and with commercially available software. This effect is induced by the alternating electric field that is part of the electromagnetic radiation. We measure the shift in the LC resonant frequency by placing materials with different permittivity within the gap of the SRR. The results of our expertiment reveal the high sensitivity of split-ring resonators to subtle changes in their environment, necessary in biosensing applications. | Peria, William Terpening, Ryan | Peria, William | Terpening, Ryan | 1392 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13pulsednmr | ||||
| 2013-05-10 00:00:00 | Optics | Fourier Transform of Light Using a Constructed Spatial Light Modulator | We constructed a low-cost spatial light modulator used to create two-dimensional optical Fourier transformations in the far field; a comparison of observed transformations to theoretical models generated computationally was conducted for several transmission patterns. Observed optical Fourier transformations of circular and square apertures matched theory with reduced chi^2 values of 5.78 and 10.43 respectively. | Frink, Ryan Geldert, Sean | Frink, Ryan | Geldert, Sean | 1352 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13fouriertransformoflight | ||||
| 2013-05-10 00:00:00 | Condensed Matter Physics | Helmholtz Resonator in Superfluid Helium | In a double-chambered resonator, measurements of Helmholtz resonances were taken by submerging in liquid helium cooled below the lambda point, 2.18 K, at which superfluid components appear. Fractional abundance of superfluid helium component to normal fluid component were calculated. A previous attempt at this measurement in the spring 2012 MXP II course was not able to produce a sensible result. Frequency responses were found at varying temperatures but the expected shift in frequency for Helmholtz resonance was not detected. | Allen, Shane Young, Ian | Allen, Shane | Young, Ian | 1331 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13helmholtzresonatorinsuperfluidhelium | ||||
| 2013-05-10 00:00:00 | Cosmic Ray Experiments | Verifying Special Relativity as a Mechanism for Muon Penetration | We observe the full-spectrum muon flux as a function of altitude via high-altitude weather balloon. We find that the logarithm of flux versus depth has a linear slope of (-0.00547±3.3*10^-5)cm²/g with a reduced chi² of 0.23, which, while differing significantly from Bruno Rossi's 1940 finding of approximately -0.003, is likely within the margins of error introduced by differences in experimentation between Rossi's setup and ours, and qualitatively matches the behavior observed by Rossi. We use a simulation to show that velocity-dependent time dilation as a mechanism for deeper muon penetration provides a model that is in close agreement with observations for the 300-700 g/cm² range, with a reduced chi² in that range of 0.20, and a reduced chi² of 6.58 over the entire range considered. We further explore possible causes of the low-altitude deviation between our model and the observed flux | Mackenzie, Jasmine Paradise, Adiv | Mackenzie, Jasmine | Paradise, Adiv | 1311 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13specialrelativitymuon | ||||
| 2013-05-10 00:00:00 | Condensed Matter Physics | Indirect Electron Tunneling in Germanium Using a Current to Detect Resonant Phonon Energies | In this experiment, a germanium tunneling diode was cooled using liquid helium to a temperature of 4.2K, at which point a voltage potential was applied across the diode, and a measurement of the current moving through the diode was recorded. By looking at the I-V curve, the first derivative (dI/dV), and the second derivative (dI^2/dV^2) of the I-V curve, the LO and TA mode resonant energies of the tunneling diode for maximum phonon emission were determined to be E_TA=(4.8±0.9) meV, with a (chi_R)^2=0.971, and E_LO=(30.2±1.1) meV, with a (chi_R)^2=0.994. | Coles, Matthew Glasenapp, Samuel | Coles, Matthew | Glasenapp, Samuel | 1332 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/home/2013---spring/s13indirectelectrontunneling | ||||
| 2013-05-10 00:00:00 | Condensed Matter Physics | Liquid Crystal Reflectivity | The Smectic A layer spacing of a freely suspended film of 65OBC (n-hexyl-4’-n-pentyloxybiphenyl-4-caboxylate), a liquid crystal, was determined through optical reflectivity measurements. The reflectivity of the perpendicular component of light off of a freely suspended film was measured and utilizing the fact that the number of layers is quantized, the layer spacing was deduced to be (24.2±0.2) Angstroms. To our knowledge the value of this layer spacing has never been published but a rough estimate can be given by the length of the 65OBC molecule, which is ~25 Angstroms, which is in good agreement with our data. | Haun, Garrett Markham, Benjamin | Haun, Garrett | Markham, Benjamin | 1333 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13liquidcrystalreflectivity | ||||
| 2013-05-10 00:00:00 | Cosmic Ray Experiments | Measuring the Angular Distribution of Cosmic Ray Muons Using a Scintillator Telescope | The angular distribution of muon flux generated from cosmic ray showers was measured using pairs of scintillation panels coupled to photomultiplier tubes. The distribution was measured first as a function of the angle q from the vertical; the results indicate a distribution of (cos(theta))^k dOmega with k = 3.7 ±0.2 for theta< 30 degrees, flattening out for larger angles, which contrasts with the expected (cos(theta))^2 dOmega distribution for medium-energy muons in the 3 GeV range. The distribution was also measured as a function of azimuthal angle phi (corresponding to cardinal direction). A small (< 5%) effect due to the Earth’s magnetic field was expected whereby a higher flux would be measured from the west than from the east. Instead, the opposite effect was measured, with the greatest flux coming approximately from the southeast and with an overall variation of 17 - 24%. These results are thought to be the result of shielding by the building in which the apparatus was located, the Tate Laboratory of Physics, and provide an interesting insight into the shielding profile of the building. | Bergerud, Brandon Veit, Max | Bergerud, Brandon | Veit, Max | 1312 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13scintillatortelescope | ||||
| 2013-05-10 00:00:00 | Condensed Matter Physics | Measurement of the Magnetic Susceptibility of Liquids | The magnetic susceptibilities of the several liquid samples have been measured by applying only the order of 0.25 T magnetic fields with simple apparatus and technique. The energy balance between the magnetic energy and the gravitational potential of the liquid interaction is used to determine the susceptibility. The measurement proceeded by neglecting the surface tension effect. Water was used for the calibration for this experiment. Three CuSO_4(5H_2O) solutions with different densities, and NaCl have been selected in a range of diamagnetic to paramagnetic and their magnetic susceptibilities have been determined(-2.78 ± 0.76)x10^-6, (5.81± 0.71)x10^-6, (2.11 ± 0.22)x10^-5 and (-1.67 ± 0.16)x10-5 respectively. | Seo, Hyelee | Seo, Hyelee | 1334 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13magneticsusceptibilityliquids | |||||
| 2013-05-10 00:00:00 | Cosmic Ray Experiments | Measuring the Velocity of Cosmogenic Muons | Using coincident scintillator panels and photomultiplier tubes the mean velocity of cosmogenic muons was measured to be v_mu= = (0.926 ± 0.018) c which is 3.5 sigma below the accepted value of 0.99 c. The data collected in this experiment showed an unusual dependence on the detector energy threshold which somewhat reduces our confidence in this result and helps explain the discrepancy from the accepted value. The mean velocity measurement was made by measuring the mean time of flight of muons through the detector apparatus in many different configurations and comparing the times to the mean path length of muons through the detector generated from Monte Carlo simulations. | Antos , Blake Epland, Matthew | Antos , Blake | Epland, Matthew | 1313 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13measuringmuons | ||||
| 2013-05-10 00:00:00 | Cosmic Ray Experiments | Measuring the Momentum Distribution of Cosmogenic Muons | The cosmic ray muon momentum distribution from 1.5 to 3.5 GeV/c is measured using an argon gas threshold Cherenkov detector. The momentum distribution is fit to a power law distribution with exponent alpha, based on expectation of known empirical data. A value of -0.84±0.19 is measured for alpha, which is consistent to within 0.4 sigma with the established empirical value of -0.76±0.05. | Kelley, Tyler Stifter, Kelly | Kelley, Tyler | Stifter, Kelly | 1314 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13cherenkovradiation | ||||
| 2013-05-10 00:00:00 | Particle Experiments | Mössbauer Spectroscopy | In this experiment, we attempted to utilize the Mössbauer Effect to measure the isomer shift, delta, the quadrupole splitting energy, µ, and the Zeeman Splitting energies, Delta0 and Delta1, of Fe foil, Fe2O3, and Fe3O4. We accomplished this by observing the resonant absorption of Fe2O3 and Fe3O4 absorbers. The Doppler Shift was used to probe the hyperfine splitting of the nuclear transition energies. | Chen , Cong Vold, Andrew | Chen , Cong | Vold, Andrew | 1321 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13moessbauer | ||||
| 2013-05-10 00:00:00 | Condensed Matter Physics | Measurement Of T2 Relaxation Times Near Phase Transition For Cyclohexane | Investigation of change in the spin-spin relaxation time, T_2, was conducted by pulsed nuclear magnetic resonance (NMR) spectroscopy techniques for cyclohexane, C_6H_12, as the sample went through phase transition from a solid state to a liquid state. It has been established that temperature and sample phase state effects NMR measurements, though there is not complete understanding regarding the behavior of nuclei during a phase transition. The individual solid and liquid T_2 relaxation times were measured simultaneously as a function of time while the sample melted in order to attempt to measure their fraction. An asymptotic approach to an all liquid sample was observed and the solid and liquid T_2 times were successfully separated from a single signal. | Alt, Rory | Alt, Rory | 1335 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13nmr | |||||
| 2013-05-10 00:00:00 | Optics | Properties of Helium Neon Lasers | We construct a Helium Neon (HeNe) laser to determine the relationship between mode beating and the cavity length of the laser. A coherent beam of light is emitted by the laser when standing waves, or longitudinal modes, are produced within the cavity. Usually multiple longitudinal modes oscillate simultaneously at varying frequencies. We intend to relate the difference between adjacent frequencies, the beat frequencies, to the spatial properties of the laser beam and the length of the lasing cavity. | Rich, Stephanie Stein, Josh | Rich, Stephanie | Stein, Josh | 1353 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13henelaswers | ||||
| 2013-05-10 00:00:00 | Optics | Single Photon Quantum Interference | We demonstrate single photons and their self-interference using a source of correlated photon pairs. We first establish the existence of individual photons, showing that they violate the classical prediction for wavelike behavior by 54 standard deviations. However, when these photons are directed into an interferometer, they exhibit wavelike properties and form a sinusoidal interference pattern. Furthermore, we demonstrate the phenomenon of quantum erasure, in which interference can be destroyed and recovered depending on the photon path information. | Gray, Isaiah Wagner , Joel | Gray, Isaiah | Wagner , Joel | 1354 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13singlephotonquantuminterference | ||||
| 2013-05-10 00:00:00 | Condensed Matter Physics | Speed of Transverse Second Sound Waves in Liquid Helium II | We mechanically stimulate transverse second sound waves in liquid Helium to determine the speed of second sound by measuring the frequencies at which resonances are produced in a cylindrical cavity. We obtained the speed of second sound for ten temperatures ranging from 1.75 K to 2.171 K. The speed of second sound at 2.171 K (0.005 K away from the Lambda Point) was calculated to be 4.47±0.044 m/s. This value was 2.59 sigma away from the expected value of 4.533 m/s. We also analyzed the temperature dependent characteristics of a resonance peak in frequency space whose mode is defined as m=4, n=0. | Belanger, Max Edens, Michael | Belanger, Max | Edens, Michael | 1336 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13secondsoundhe2 | ||||
| 2013-05-10 00:00:00 | Condensed Matter Physics | Spin Noise Spectroscopy of Rubidium (Rb) Vapor | The aim of this experiment was to demonstrate that spin noise spectroscopy is a viable non-perturbative technique for measuring atomic properties. Spin noise spectroscopy uses Faraday rotation to detect intrinsic spin fluctuations from which several atomic properties can be measured. In this paper we probe Rubidium 85 and 87 with spin noise spectroscopy to determine their g-factors, the isotope abundance ratio, their hyperfine splittings, and the spin coherence lifetimes. A value of 0.4992 ± 0.006 was found for the g-factor of 87Rb which is 1.3 standard deviations from the accepted value. The g-factor of 85Rb was not found. A value of 4.7 ± 0.2 was found for the isotope abundance ratio, which is 15.5 standard deviations from the accepted value. The spin coherence lifetime was measured to be (8.39 ± .03) microseconds, which is 64 standard deviations from the accepted value. The hyperfine splitting of 85Rb was determined to be 12.01 ± 0.14 microeV and the hyperfine splitting of 87Rb was determined to be 26.90 ± 0.27 microeV, which are 3.7 and 5.1 standard deviations from their respective accepted values. | Nangoi , Johannes Welter, Roland | Nangoi , Johannes | Welter, Roland | 1337 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13spinnoisespectroscopy | ||||
| 2013-05-10 00:00:00 | Misc | Fluorescent Lifetime of the Singlet State and Fluorescent Quantum Yield of Zinc Phthalocyanines | The alkoxide substituents effects on the quantum yield on the two different zinc phthalocyanines, zinc 2,3,9,10,16,17,23,24-octakis (octyloxy)-29H,31H-phthalocyanine (ZnPcOR1) and zinc 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (ZnPcOR2) are compared to the regular zinc phthalocyanine (ZnPc). The first excitation wavelength for ZnPcOR2 is red shifted 67 nm compare to ZnPc, where as ZnPcOR1 only has a red shift value of 6 nm. The fluorescent quantum yield (QYf) for ZnPcOR2 has the value of 18.6±2.1 %, which is 50.6±5.9 % less than the QYf for ZnPc. The unexpected 50.6±5.9 % drop in QYf in ZnPcOR2 is due to the alkoxide substituents in ZnPcOR2 have steric interaction with one and another that causes the deformation of the planar structure of phthalocyanines, which lowers the energy gap between the ground state and the first excited state. | Lee, Hua-Kuang | Lee, Hua-Kuang | 1393 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13fluorescentlifetimeofthesingletstate | |||||
| 2013-05-10 00:00:00 | Condensed Matter Physics | Temperature Dependence of a Doped Semiconductor and Measuring the Hall Effect | In this experiment we measure the conductivity of and calculate charge carrier mobility in a boron doped silicon semiconductor. The conductivity was measured to follow a power law of Sigma =(6.3x10^4)T^(2.01 ± 0.014) between 200 and 300 K. This is 50.7 sigma above the expected result of Sigma =(3.6x10^6)T^2.72 . In the same temperature range, the mobility followed power law of mu_p =(8.5x10^7)T^(2.02 ± 0.015). This result is 18.7 sigma above the expected power law of mu_p =(2.5x10^8)T^2.3. Between 10 and 35 K, the conductivity followed an exponential law of Sigma =0.11e^(0.12 ± 0.003(T)). This is 110.7 sigma below the expected result of Sigma=(2x10^10)e^0.4522(T). In this temperature range, the mobility was found to follow a power law mu_p =(5.1x10^7)T^(2.52 ± 0.24). This is 4.3 sigma below the expected result of mu_p ~T^1.5. | Olson, Nicole Ross, Hannah | Olson, Nicole | Ross, Hannah | 1338 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2013---spring/s13halleffect | ||||
| 2012-05-04 00:00:00 | Misc | Cyclotron Resonance in Fluorescent lamp Plasma | We measured the change in frequency of a microwave signal resonating in a copper pipe (waveguide) when the index of refraction inside the pipe is altered by the presence of unmagnetized or magnetized collisionless plasma. We reproduced an experiment described by Julie Orr and Richard Wolfson, in which a collisionless plasma is provided by the decaying plasma of a fluorescent lamp just after it is turned off. The change in resonant frequency when the magnetic field strength is turned on can be used to calculate the electron density in the waveguide at a given time in the plasma?s decay. We expected the electron densities to be on the order of 10^15 to 10^17 m-3 and decaying with a time constant of at least 0.5 ms. Our results showed the electron density decreasing exponentially from an initial extrapolated value of 7±1x1016 ??-3 with a time constant of 3.2±0.8 ????. | Cameron, Mac Hanson, Lily | Cameron, Mac | Hanson, Lily | 1290 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12cyclotronresonance | ||||
| 2012-05-04 00:00:00 | BioPhysics | Molecular Tumbling of Myosin S1 measured by Fluorescence Anisotropy | Myosin S1 is the catalytic domain of the myosin molecular motor. The rate of tumbling in solution can be determined from the anisotropy function which decays at the time scale of the motion. To find the anisotropy function we will measure vertical and horizontal emission of AEDANS-labeled myosin S1 using a time-resolved spectrometer. We found that our sample contained free and immobile fractions of S1 (~45% immobile). Using nonlinear regression we found the rotational correlation time of free S1 was (75±11) ns, a departure from the previously reported value of (220±5) ns. | Petersen, Karl | Petersen, Karl | 1261 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12moleculartumblingofmyosin | |||||
| 2012-05-04 00:00:00 | Cosmic Ray Experiments | Angular Correlation of Positron Annihilation | The angular distribution of photons emitted from electron-positron annihilation was measured over an angular range of 180-138 degrees. High energy gamma rays emitted by 60Co were used to produce positrons which annihilated with electrons in a lead target. The photons created during the annihilation were detected and measured using a coincidence circuit and amplified above the background. The angular distribution of photons emitted from at-rest annihilations was plotted and compared to a fit accounting for the solid angle in the detectors with a reduced Chi Squared of 1.72. In-flight annihilations were unable to be resolved and the in-flight to at-rest annihilation ratio was inconclusive. | Duffield, Emily Veit, Mike | Duffield, Emily | Veit, Mike | 1213 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12angularcorrelationpositronannihilaion | ||||
| 2012-05-04 00:00:00 | Condensed Matter Physics | Helmholtz Resonances in Helium near Lambda Point | In liquid helium below 2.18K, two components termed the superfluid and normal fluid coexist. In our experiment we attempted to measure the temperature dependence of the relative abundance of the superfluid component of liquid helium. To this end we explored the Helmholtz resonance frequency as we varied the temperature in an experimental cell. The key characteristic of the experimental cell was the presence of filter channels which allowed for the superfluid (which had zero viscosity) to flow freely while preventing the flow of the normal fluid. | Kasper, David Brown, George | Kasper, David | Brown, George | 1231 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12helmholtzresonancesinhelium | ||||
| 2012-05-04 00:00:00 | Condensed Matter Physics | Modulation of Conductivity in Platinum via Electrochemical Gating | We attempted to modulate the resistance of a platinum film using an ionic fluid. A capacitor is formed between two thin films of platinum so that when a gate voltage is applied, the plates will accumulate charge using the ionic fluid to increase capacitance. Since the electrons act as charge carriers, the charge will modulate the resistance of the film. Using this technique a resistance change of 0.476 +/-0.007% was achieved. Additionally, if the ionic fluid was contaminated with copper ions a resistance change of 4.927+/- 0.007% was achieved. | Redford, Joe Rockwell, Marshall | Redford, Joe | Rockwell, Marshall | 1232 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12conductivityinplatinum | ||||
| 2012-05-04 00:00:00 | Cosmic Ray Experiments | Characterizing the Strength of the Weak Force from an Observation of Muon Decay | In this experiment, the Fermi Coupling Constant, GF, was deduced. The mean lifetime was found to be (2.187 +/- 0.021)µs. GF was found to be (1.16614 +/- 0.0061) x 10-5 GeV-2. | Singh, Jason | Singh, Jason | 1212 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12weakforce | |||||
| 2012-05-04 00:00:00 | Misc | Microwave-induced Photovoltage due to Ferromagnetic Resonance | We have measured photo voltage induced by ferromagnetic resonance in a permalloy sample (Ni81Fe19). By placing a short at the end of a microwave waveguide, we generate a standing electromagnetic wave that provides the microwave magnetic field necessary for ferromagnetic resonance. We then look at the dc photo voltage induced by the phase difference between the resistance and the current in the sample. Through this we show that the photo voltage response can be eliminated at the electric field node but cannot be eliminated at the magnetic field node. | Kamp, Eric Kooistra, Jon | Kamp, Eric | Kooistra, Jon | 1293 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12microwaveinducedphotovoltage | ||||
| 2012-05-04 00:00:00 | Optics | Measurement of Thermal Expansion using Multiple Exposure Holographic Interferometry | Using holographic interferometry, we measured the thermal expansion coefficients of copper, iron, and aluminum. The values obtained were (16.78±0.46)×10-6, (12.02±0.43)×10-6, and (27.05±0.41)×10-6 K-1 for copper, iron, and aluminum respectively. | Holmstadt, Scott Gunderson, Jeff | Holmstadt, Scott | Gunderson, Jeff | 1250 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12measurmentofthermalexpansion | ||||
| 2012-05-04 00:00:00 | Acoustic | Accuracy and Precision of Acoustic Range Measuring Techniques | Two amplitude modulation techniques were studied with the goal of determining the accuracy and precision of acoustic distance measurements as functions of object distance and size, carrier signal, and modulation signal. The first technique was using maximum length sequences to modulate a carrier signal and the second was the sinusoidal modulation of a carrier signal. The sinusoidal method proved to be too inaccurate to use for reliable distance measuring while the maximum length sequences were showing ± 1 to 2mm precision and accurate measurements over the measured range of 0.5 to 5m. | Johnson, Luke Kranz, Joshua | Johnson, Luke | Kranz, Joshua | 1270 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12accousticrangemeasuringtechniques | ||||
| 2012-05-04 00:00:00 | Condensed Matter Physics | On the Efficacy of Thermal Grease across Copper-Copper Junctions | We sought to answer the question of whether the use of thermal grease such as Apiezon actually succeeds in increasing the thermal conductance across a junction between two blocks of metal. Our method was to dissipate a controlled amount of power across a copper-copper junction at liquid helium temperatures (~4.2 Kelvin), and to measure the resulting temperature gradient once the system reached thermal equilibrium. We found that, due to major systematic uncertainties including inconsistent calibration of our temperature sensors, we were unable to conclude that Apiezon grease is any more effective at conducting heat than bare metal surfaces. | Ditter, Alex Pittman, Jacob | Ditter, Alex | Pittman, Jacob | 1230 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12efficacyofthermalgrease | ||||
| 2012-05-04 00:00:00 | Cosmic Ray Experiments | Characterization of the Natural Gamma Ray Background Emission at the CDMS Detector Testing Facility | We employed a high-purity germanium (HPGe) detector to characterize the natural gamma ray background in the Cryogenic Dark Matter Search (CDMS) Detector Testing Facility. We were concerned primarily with a strong 40K source of unknown origin which has been interfering with the detector testing. In order to properly shield against the background and the 40K source, a proper understanding of the background is necessary. To this end, we constructed a lead enclosure around the HPGe to determine how effective lead shielding would be at attenuating the background gamma rays. Using this lead enclosure, we determined what, if any, directional component existed to the 40K background, and observed other non-homogeneous characteristics to the natural background. | Emerick, Andrew Weir, Karley | Emerick, Andrew | Weir, Karley | 1210 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12gammaraybackgroundemissioncdms | ||||
| 2012-05-04 00:00:00 | Optics | Measurement of Fluid Velocity Using Laser Doppler Velocimetry | Laser Doppler Velocimetry is utilized to measure the flow velocity of water pumped through transparent glass tubing. When the water is seeded with particles, the particles pass through an interference region at the intersection of two coherent laser beams and reflect light into a photomultiplier tube. A burst signal is observed, and particle velocity is calculated from its frequency. The velocity profile of the glass tubing is modeled and compared to existing data and theory, and we attempt to observe at what fluid speeds laminar flow turn into turbulent flow. | Gleason, Benjamin Peterson, Elias | Gleason, Benjamin | Peterson, Elias | 1251 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12measrementoffluidvelocity | ||||
| 2012-05-04 00:00:00 | Atomic Physics | Measuring Hyperfine Interactions of 57Fe Compounds with Mössbauer Spectroscopy | In this experiment we used Mössbauer spectroscopy to measure the isomer shift, Zeeman splitting, and quadrupole interaction for 57Fe Foil, a-Fe2O3, and Fe3O4 through recoilless absorption of a photon. The recoilless emission of gamma rays from a 5mCi radioactive source of 57Co allowed it to emit 14.4keV gamma rays with a precision on the order of 10-9 eV. This resolution is smaller than the hyperfine transition energies of the iron nuclei by more than a factor of 10. By oscillating the 57Co source by mm/sec, toward and away from the iron compound, we were able to Doppler shift the emitted 14.4keV gamma ray by several 10-8 eV, and create varying energies that formed a distribution centered around 14.4keV, which were used to measure the absorption energies due to the hyperfine energy structure of iron. The energies were determined by decreased counts at measured Doppler velocities. All calculated quantities were found to be within the uncertainties of our experiment and that of the literature, with the exception of the ground state Zeeman splitting of a-Fe2O3, the average excited state Zeeman splitting of Fe3O4, and the average isomer shift of Fe3O4 at room temperature. | Kremin, Anthony Resch, Josh | Kremin, Anthony | Resch, Josh | 1240 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12mossbauerspectroscopy | ||||
| 2012-05-04 00:00:00 | Misc | Quality Factor Characterization of Magnetic Materials using Magnetic Force Macroscopy | Using a technique dubbed magnetic force macroscopy, this experiment attempted to characterize changes in the magnetic properties A36 steel in response to permanently induced strain. As a magnetic material is strained, it is expected that magnetic domain walls will increase in number and will be pinned to the deformations created as the metal is stretched. Using an oscillating cantilever with a strong neodymium magnet at the tip, we investigated the energy loss of the cantilever?s motion due to the magnetic field?s interaction with the magnetization present in the metal sample. The energy loss due to the magnetic interactions was expected to produce changes in the shape of the resonance curve of the cantilever, and could therefore be measured by determining the quality factor of the cantilever?s response. Our team attempted to identify strained regions by determining this Q-factor at regular intervals over several samples. Due to what we believe is a lack in the sensitivity of our equipment, we were unable to find any measurable change in the shape of the resonance curves, and thus no measureable change in energy loss was observed. | Brown, Charles Hepler, Mike | Brown, Charles | Hepler, Mike | 1291 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12qualityfactormagneticmaterials | ||||
| 2012-05-04 00:00:00 | Condensed Matter Physics | Speed of Second Sound Transverse Waves in Liquid Helium | Transverse waves, waves propagating perpendicularly to the cylindrical container?s vertical axis, were used to measure the speed of second sound in liquid helium near the lambda point. The liquid helium was housed in a flat cylindrical container. Using two electrodes and an aluminum diaphragm, the second sound was driven at a specific frequency by one of the electrodes. The second electrode detected the second sound wave created by the driver. The resonance frequency of the detected wave was then related to the speed of second sound. All final values for the speed of second sound were within 3 standard deviations of the expected values for each temperature. | Chorn, Michelle Giolas, Lucas | Chorn, Michelle | Giolas, Lucas | 1234 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12speedofsecondsoundhe | ||||
| 2012-05-04 00:00:00 | Misc | Speed of Sound in Bubbly Liquids | The acoustic property of a liquid will dramatically changes when a small amount of gas is added in it. A simple mathematical model, Wood's equation, predicts the relationship between the speed of sound in such a liquid in the low frequency limit and the void fraction ? (the volume fraction of the gas phase). In this experiment, we verified Wood's equation by investigating the speed of sound in a bubbly liquid contained in a half-meter long waveguide. Our Measurements of the resonance frequencies of the sound using a hydrophone and a simple electronic circuit determined the speed of sound within the liquid at different volume fractions ranged from 0.2% to 3.4%. In order to demonstrate this effect in an audible and pleasing way, an amplified loudspeaker system is also used to broadcast the signal. | Wu, Chengjian Youmans, Cody Zhang, Kaiwen | Wu, Chengjian | Youmans, Cody | Zhang, Kaiwen | 1292 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12speedsoundinbubblyliquid | |||
| 2012-05-04 00:00:00 | Atomic Physics | Spin-Lattice and Spin-Spin Relaxation Times of Water Doped with Paramagnetic Ions [NMR] | Nuclear magnetic resonance spectroscopy was used to study microscopic magnetic interactions between the hydrogen nuclei and local molecules of water samples with different concentrations of CuSO4. The energy exchange and mechanics of these magnetic interactions are described with two material-specific relaxation times: spin-lattice and spin-spin. The spin-lattice and spin-spin relaxation times for each concentration were measured to observe the effect of these paramagnetic ions on the water molecules; higher concentrations increased the rate of energy exchange through dipolar relaxation, resulting in a decrease of relaxation times. We used pulsed nuclear magnetic resonance with radio frequency magnetic field pulses and compared our results to values found in literature. The measured T1 and T2 values decreased monotonically with increasing concentrations of CuSO4, however, T2 values deviated farther from expected literature values. | Dorow,Chelsey Storino, Chris | Dorow,Chelsey | Storino, Chris | 1241 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12nmr | ||||
| 2012-05-04 00:00:00 | Condensed Matter Physics | Determination of the Energy Distribution of Defect States in Semiconducting Films Bandgap Tails | We report on the determination of the energy distribution of defect states existing in the conduction band tail of various semiconducting films composed of hydrogenated mixed-phase amorphous/nanocrystalline silicon (a/nc-Si:H). Our goal was to determine how the distribution of defect states depends on the volume concentration of nanocrystalline silicon. Our results indicate that low densities of nanocrystalline (2-5%) produce more defect states than pure amorphous silicon. | Hanninen, Adam Mackey, Mark | Hanninen, Adam | Mackey, Mark | 1233 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12energydistributionofdefectstates | ||||
| 2012-05-04 00:00:00 | Cosmic Ray Experiments | Measuring the Energy Distribution of Cosmic Ray Muons Using a Cerenkov Detector | To determine the shape of a portion of the cosmic ray muon energy distribution, we constructed a threshold Cerenkov detector sensitive to muons with energies between 1 and 5 GeV. After measuring the integral muon intensity at nitrogen pressures between 1 and 10 atm, the data was fit based on a diffusion model of muon production by pions in the Earth?s atmosphere which describes the integral energy distribution as a power law with exponent ?-1. The best fit value for the was calculated to be 2.77 +/- 0.20, which is 0.25 sigma higher than the value obtained by B.C. Rastin (2.72 +/- 0.01). Although the accuracy of our result was greatly limited by our device?s low muon detection efficiency, we contend that the effectiveness of our detector design could be significantly improved with a few minor design adjustments, and thus we conclude that it is feasible to use a threshold Cerenkov detector to accurately measure the shape of the cosmic ray muon energy distribution. | Ambrose, Mitchell Jawson, Aaron | Ambrose, Mitchell | Jawson, Aaron | 1211 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12energydistributionofcosmicrays | ||||
| 2012-05-04 00:00:00 | Optics | Measuring the Speed of Light Using a Wavelength-Tunable Super-Luminescent Diode Laser with a Variable, External Feedback Cavity | In this experiment a wavelength-tunable diode laser was constructed using a super-luminescent diode (SLD) as the optical source. The optical feedback cavity was external to the SLD mount by design, and consisted of a reflective diffraction grating which allowed for stimulation of specific lasing modes distributed throughout the spectral width of the SLD output in the range of 828 to 836nm. By placing the SLD on a linear mount, the external cavity was variable with a total range of (5±0.5) cm. A Fabry-Perot interferometer was utilized to view the external cavity resonant modes, which had spacing on the order of 10-12m. The external mode spacing had a linear dependence on both the speed of light and the cavity length, and therefore by varying the cavity length and measuring the mode separation, the speed of light was extracted from this simple relation. We measured the speed of light to be (2.92±0.234±1.3%)x108 m/s. This result was 0.312 standard deviations from the accepted value. | Card, Alex Farinella, Deano | Card, Alex | Farinella, Deano | 1252 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12measuringspeedoflight | ||||
| 2012-05-04 00:00:00 | BioPhysics | Measurement of the Translational Diffusion Constant of Nano-sized Polystyrene Spheres with Dynamic Light Scattering Techniques | This experiment examined the use of dynamic light scattering using nano-sized polystyrene spheres undergoing Brownian motion. The goal was to determine the translation diffusion constant and compare it to the theoretical Stokes-Einstein relationship. By analyzing the power spectrum, the half width half max was given as G, which is proportional to the diffusion constant, D. When the data was plotted as G versus diameter, the experimental results showed a -1.61s difference from theory. G is proportional to the inverse of the diameter of the spheres. The theoretical Gd=(2.77±0.063)x105nm/s. The experimental Gd=(2.63±0.059)x105nm/s. | Hansen, Josh Jennings, Ann | Hansen, Josh | Jennings, Ann | 1260 | File Cabinet | https://sites.google.com/a/umn.edu/mxp/student-projects/2012---spring/s12measurementoftranslationaldiffusionconstant | ||||
| 2011-05-06 00:00:00 | Nonlinear Systems | Determining Chaotic Parameters of the Damped Driven Pendulum | A damped driven pendulum was used to study the chaotic phenomena associated with the angular properties of the pendulum. A rotary encoder was attached to a physical pendulum to determine the angle of the pendulum at a given time. The response of the Poincare? section was observed for various driving frequency and damping values. The system showed chaotic tendencies near the driving frequency of 445 Hz as depicted by a non-negative Lyapunov exponent whose value was ascertained to be 0.278±0.044 hr-1. | Clasen, Anthony Glaser, Charles | Clasen, Anthony | Glaser, Charles | 1180 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_Chaos/ | ||||
| 2011-05-06 00:00:00 | Misc | Determination of the Limiting Crack Propagation Velocity in Silicon Wafers | Crack propagation has been theorized to be limited by the Rayleigh wave speed within solids as a crack is in essence a mechanical transfer and can be viewed as a propagating wave front. Through the use of a fast oscilloscope, we have measured the velocity of crack development within silicon wafers by measuring the varying resistance of a wafer during fracture. Wafers were statically loaded in uniaxial tension at stresses up to ~15 MPa resulting in observed velocities at up to (4930±100) m/s, or approximately (63±2) % of the Rayleigh wave speed. Though the Rayleigh wave speed was not exceeded further experiments at higher static loadings or dynamic loadings are possible. | Jacobs, Alan Ohrt, Andrew | Jacobs, Alan | Ohrt, Andrew | 1190 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_CrackPropagation/ | ||||
| 2011-05-06 00:00:00 | Misc | Demonstrating the Quadratic Dependence of Current on Mass by the Magnetic Suspension of a Steel Ball | The Bureau International des Poids et Mesures is currently exploring a method of balancing a magnetic force with gravitational force in order to replace the definition of the kilogram as a physical reference mass with a relation among fundamental constants. Inspired by their experiment, we investigated using a magnetic field to suspend a steel sphere. Suspension is achieved when the magnetic force directly opposes the local force due to gravity. Equating the forces, it can be demonstrated that the solenoid driving current should vary quadratically with respect to a linear change in the suspended mass. We were unable to verify or refute this claim because of systematic errors and time constraints, but the problems we faced can be used to improve upon our methodology in a future experiment. | Walstrom, Brian Willmert, Justin | Walstrom, Brian | Willmert, Justin | 1191 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_ElectromagneticSuspension/ | ||||
| 2011-05-06 00:00:00 | Misc | Operating a Small Driven-Damped Foucault Pendulum | Methods to unmask Foucault precession in a short (1.3 meter), driven pendulum are explored. A large scale (tens of meters) Foucault pendulum will show precession due to the Coriolis force for days when left untouched. A small pendulum experiences greater perturbations from the effects of vibration, air resistance, apparatus imperfections and intrinsic elliptical precession, which will mask the Foucault precession. We strive to nullify the perturbations. The pendulum is driven electromagnetically and unwanted motion damped with eddy currents or friction. We develop detection methods for the two-dimensional path of the pendulum. | Kutkiewicz, Peter Madland, Mark | Kutkiewicz, Peter | Madland, Mark | 1192 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_Foucault/ | ||||
| 2011-05-06 00:00:00 | Misc | Hydrogen Cyclic Voltametry | We have investigated the possibility of using a magnetite anode to electrolyze water and achieved steady state currents of up to 6.02×10-4 A. The consumable magnetite electrode actively participates in the endothermic chemical reaction and supplies some of the free energy needed for the reaction, while the remainder is supplied electrically. We have searched several possible solid-state, chemical, and electrical conditions to extremize the asymptotic current, limited by diffusive processes, which may be exploited in the context of hydrogen generation in alternative energy economies. Cyclic and step voltammetry are the standard techniques in electrochemistry that formed the basis for our experimental investigation. | Berntson, Bjorn | Berntson, Bjorn | 1193 | File Cabinet | ||||||
| 2011-05-06 00:00:00 | Cosmic Ray Experiments | Target Nuclei Properties and Electron-Positron Pair Production | In this experiment, gamma rays are used to produce e-/e+ pairs in a variety of target materials. Pair production events are measured with a coincidence detector calibrated to receive photons at around 511 keV of energy. We use a Cobalt-60 gamma ray source and dual solid NaI scintillators to measure the rate of pair production in Aluminum, Iron, Copper, Molybdenum, and Lead. We also test the difference in pair production properties between solid matter and powder for Iron and Aluminum. The number of detected coincidence events at 511 keV for each target material is compared to that of a reference material. This comparison yields a ratio of the cross section for pair production of each target material normalized to the reference material. Another relevant part of our data for analysis is the deviation of these relative cross section values from those of the target material at the varying widths. The effect of an additional glass casing is shown to be dissimilar across different types of materials and had other unexpected results. The effect of using powdered material instead of solid appears negligible but is not completely determined | Porter, Mitch Schultz, Timothy | Porter, Mitch | Schultz, Timothy | 1110 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_PairProduction/ | ||||
| 2011-05-06 00:00:00 | Cosmic Ray Experiments | Measurement of the Size and Incidence Angle of Cosmic Ray Showers | Using two different setups with scintillator detectors we were able to produce a decoherence curve and measure the incidence angles of cosmic ray showers, which primarily consist of muons at ground level. The size or lateral distribution of cosmic showers was found to follow the Moliere?Bethe function rather closely, the count rate deviating no more than 1.2sR from the expected rate of the Moliere?Bethe function. The incidence angle distribution density of the showers was found follow a decaying curve similar to a cos2(?) distribution. | Gaidu, Cristian Kovalev, Nikolay | Gaidu, Cristian | Kovalev, Nikolay | 1111 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_SizeofCosmicRayShowers/ | ||||
| 2011-05-06 00:00:00 | Cosmic Ray Experiments | Measurement of the Speed and Energy Distribution of Cosmic Ray Muons | The time of flight distribution of cosmic ray muons is measured for various spacings of detectors filled with plastic scintillator, allowing for a determination of the mean speed, as well as constraint of the energy spectrum below 0.95c. The use of a time-to-amplitude converter allowed for precise timing measurements and resolution of the shape of the timing distribution for each spacing, necessary for constraining the energy spectrum. The mean speed of cosmic ray muons is found to be (2.978±0.007)×108 m s-1 = (0.993±0.002)×c. The energy spectrum below 0.34 GeV was found to be consistent with a flat distribution and was parameterized with a power law of the form n(E)dE E-adE, with a best fit by (-7.9±9.1)×10-4. | McCreary, Elwood Remmen, Grant | McCreary, Elwood | Remmen, Grant | 1112 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_SpeedofMuons/ | ||||
| 2011-05-06 00:00:00 | Condensed Matter Physics | Magnetization Measurements of Localized Cooper Pairs in Indium Oxide | Evidence suggests that Cooper pairs precipitate in localized regions of InOx when a magnetic field is used to tune the sample outside of the superconductor phase. Detection of these localized pairs was attempted through magnetization measurements of 100Å thick InOx. | Clement, Colin | Clement, Colin | 1130 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_CooperPairs/ | |||||
| 2011-05-06 00:00:00 | Condensed Matter Physics | Giant Magnetoresistance in a Single Homogenous Thin Film of Permalloy | We have observed the giant magnetoresistance (GMR) in the domain wall of a single layer of Permalloy metal (Py) using two rotating spatially distinct magnetic fields. The resistance of the Permalloy increased as the magnetization of each end changed from zero to 180 degrees. The maximum change in resistance was obtained when the magnetizations were 180 degrees apart as expected in GMR experiments. These changes in the resistance are a result of an induced magnetoresistance in the domain wall. The results are that the GMR effect can be seen in a single layer of Py as opposed to the typical multi-layer configurations. That maximum experimentally determined percent change was found to be 2.8% | Guzik, Joseph | Guzik, Joseph | 1131 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_GMR/ | |||||
| 2011-05-06 00:00:00 | Condensed Matter Physics | Heat Capacity of Liquid Helium in the Vicinity of the Lambda Point | Liquid helium undergoes a phase transition at roughly 2.17 K to a superfluid state, which has a variety of special properties, most notably zero viscosity and infinite thermal conductivity. We intend to investigate the behavior of the heat capacity across this transition, which has been shown to tend to infinity at the point of transition. Precise thermometry techniques will be utilized to measure the heat capacity as a function of temperature to milliKelvin resolution. | Barquist, Colin Benton, Brian | Barquist, Colin | Benton, Brian | 1132 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_HeatCapacityHe/ | ||||
| 2011-05-06 00:00:00 | Condensed Matter Physics | Measuring the Temperature Dependence of the Energy Gap of a Niobium Superconductor Using Josephson Junctions | We used a Josephson Junction to measure how the energy gap in superconducting niobium varies with temperature. Compared to Bardeen, Cooper, Schrieffer (BCS) theory of superconductivity our measurements followed the hyperbolic tangent temperature dependence. By performing a ?2 minimization, we obtained a double energy gap at zero Kelvin of 2.82±0.38 meV, which is 0.61s away from the valued experimentally determined by Townsend and Sutton. At temperatures between 7.5 K and 9.5 K, we found that the Thouless power law approximation of the energy gap?s dependence on the square root of one minus the critical temperature held. By fitting a log-log plot of the energy gap?s dependence on temperature to a line, we found a slope of 0.477±0.053 which is 0.43s away from the theoretically expected value of 0.500. | Johnson, Caitlin Walter, Alexander | Johnson, Caitlin | Walter, Alexander | 1133 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_JosephsonJunction/ | ||||
| 2011-05-06 00:00:00 | Condensed Matter Physics | Second Sound Velocity and Precision Temperature Measurements of Liquid Helium II | In this experiment, we measured second sound velocities by cooling liquid helium below the lambda point temperature and generating second sound waves inside a cylinder. We then compared these to previously recorded values from a formula put forth by Landau(1). We then compared two separate temperature regulation techniques. One by means of a thermal resistor, and another by phase shifts in the standing waves of second sound. We found that the regulation has the potential to have greater resolution yet we were unable to achieve this. | Mack, Jesse Neish, Marcus | Mack, Jesse | Neish, Marcus | 1134 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_LambdaPointHe/ | ||||
| 2011-05-06 00:00:00 | Condensed Matter Physics | Characterization of Metals Using Macro Magnetic Force Microscopy | The magnetic force macroscope is a large scale magnetic force microscope that operates by driving a cantilever to resonance, and uses a magnet placed at the free end of the cantilever to interact with samples based on their magnetic and electric properties. The oscillating magnet induces eddy currents in conductive metals which produce a damping force on the cantilever oscillation. We determined that the strength of this interaction is proportional to the conductivity of the sample, and is also related to the first derivative of the tip's magnetic field. In addition, we found that in our particular setup, the penetration depth of the eddy current interaction is limited by the drop off in the field strength of the tip rather than the material dependent skin depth of the sample. | Chen, Zijun | Chen, Zijun | 1135 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_MacroMagneticForceMicroscopy/ | |||||
| 2011-05-06 00:00:00 | Condensed Matter Physics | Measurement of the Dipole Moments of Solutions in Water | We have used the B field from a PASCO Variable Gap Lab Magnet to create deformations in water and solutions of CuSO4 and NaCl in water. The shapes of these deformations were measured and from that measurement the dipole moments and magnetic susceptibilities of the solutions were determined. For CuSO4, the magnetic susceptibility was found to be (7.61±0.27)×10-6, and for NaCl it was found to be (-8.89±0.45)×10-6. | Warner, William | Warner, William | 1136 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_DipoleMoment/ | |||||
| 2011-05-06 00:00:00 | Condensed Matter Physics | Phase Changes in Two-Dimensional Ferrofluid Spike Crystals | We used ferrofluid in a nearly homogenous magnetic field to make a physical analog of a two dimensional crystal in order to measure its Lindemann ratio, the ratio of a particle?s root mean square displacement from equilibrium in a monatomic crystal at the onset of melting to its atomic spacing. We took photos of ferrofluid spike lattices at different magnetic field strengths and perturbation intensities below the breakdown of the order of the lattice in order to measure the root mean square displacement of the spikes from equilibrium and extrapolate the Lindemann ratio of the lattice. The average measured value was 0.065±0.066 which is 1.1 standard deviations off of the literature value of 0.14±0.02. This result is highly suspect, however, as the implementation of the experiment was plagued with fundamental difficulties. | Eskolin, Meghan Hanson, James | Eskolin, Meghan | Hanson, James | 1137 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_Ferrofluid/ | ||||
| 2011-05-06 00:00:00 | Atomic Physics | Optical Pumping of Rubidium | In this experiment we used an optical array to generate circularly polarized photons which were used to create non-thermal population inversion of a sample of two isotopes of rubidium: Rb-85 and Rb-87. With the application of a sweeping magnetic field and an RF signal we were able to examine the structure of the Zeeman states of the rubidium atoms. In this examination we were able to extrapolate values for the nuclear spins: (2.4312 ± 0.00009) for Rb-85 and (1.4599 ± 0.00011) for Rb-87. The accepted values are 5/2 and 3/2 for Rb-85 and Rb-87 respectively. We also found the time constant for optical pumping to be (13.1 ± 0.7) ms | Rodrick, James Sullivan, Michael | Rodrick, James | Sullivan, Michael | 1140 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_OpticalPumping/ | ||||
| 2011-05-06 00:00:00 | Optics | Determining the Stiffness of a Single Beam Optical Trap | Through this experiment, we determined the stiffness of the trapping force of a single-beam optical tweezers by applying a viscous drag force to a trapped transparent dielectric micron sphere. A CCD camera was used to track the position of the sphere in the trap. In addition, we determined the relationship of the laser power output to the trap stiffness. We determined the maximum trap stiffness to be (2.17±0.77)×10-6 N m-1, achieved at a laser power of 12.67±0.01 mW. The trap stiffness varied linearly with laser power at a rate of (3.25±0.50)×10-6 N m-1 mW-1. | Jordan, Michael Strandberg, David | Jordan, Michael | Strandberg, David | 1150 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_OpticalTweezers/ | ||||
| 2011-05-06 00:00:00 | Optics | Photon Counting Statistics | The characteristic nature of the coherent light source, and a pseudo thermal light source was experimentally studied by characterizing the intensity fluctuations of light sources over counting times T >> ?t and T << ?t, where is the coherence time of the light. A 1mW He-Ne laser of wavelength of 633nm was used as the coherent light source and the same laser was focused onto an aqueous suspension of polystyrene spheres undergoing Brownian motion to produce a pseudo-thermal light source. Using the laser as our light source, a Poisson distribution was observed. However, focusing the same laser at an aqueous suspension of polystyrene of diameter of 240nm, we were able to observe a Bose ?Einstein distribution that satisfied gate time, T, short compared to a coherence time of (17 ± 2) ms. | Arogundade, Simisola Kaess, Karl | Arogundade, Simisola | Kaess, Karl | 1151 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_PhotonCountingStatistics/ | ||||
| 2011-05-06 00:00:00 | Optics | Confirmation of the Wave-Particle Duality of Light by Demonstration Single Photon Self- Interference | This project demonstrates the quantum nature of light by repeating Young?s classic double-slit experiment, but with the intensity of the incident light reduced to the point that a single photon at a time traverses the length of our apparatus. We calculated the light from the source to have a coherence length of 29.7 micrometers which is much less than average separation between photons of 2.164 Km for the 2.01 volt run and 15.048 Km for the 1.4 volt run. There is no way for two photons from our light source to interfere with each other. Even with no other photons to interfere, each photon is still observed to form the pattern described in our model which was simply the wave interference equation modified to account for measurement errors. | Geach, Christopher Thomas, Benjamin | Geach, Christopher | Thomas, Benjamin | 1152 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_SinglePhotonInterference/ | ||||
| 2011-05-06 00:00:00 | Optics | Development of a Wave-Tunable Laser Using a Superluminescent Diode | In our experiment we will be using a superluminescent diode (SLD) to create a lasing device using an external cavity optical feedback mechanism. We will be exploring two parameters, what injection currents and what optical feedback ratios are necessary to create and optimize an environment conducive to lasing. We will also be using a diffraction grating to tune the laser to different wavelengths. | Altobell, Andrew Schramm, Tony | Altobell, Andrew | Schramm, Tony | 1153 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_SuperluminescentDiode/ | ||||
| 2011-05-06 00:00:00 | Optics | Measurement of Thermal Expansion Using Double Exposure Holographic Interferometry | Using double exposure holography, we were able to measure the thermal expansion coefficient of various metals. From our data, we calculated the thermal expansion coefficient for aluminum to (3.97±0.67)×10-5 K-1 and for brass to (3.74±0.84)×10-5 K-1. | Cochrane, Jed Mintz, Ryan | Cochrane, Jed | Mintz, Ryan | 1154 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_Holography/ | ||||
| 2011-05-06 00:00:00 | BioPhysics | Viscosity of Cellular Mediums Using Brownian Motion | The viscosity of media used for cell-free protein expression is thought to have significant impact on protein expression. The viscosity of four artificial biological media were determined using an optical microscope to measure the horizontal displacement of polystyrene microspheres, undergoing confined Brownian motion, from which the viscosity of the medium was determined using the Stokes-Einstein Law. The viscosities determined were (3.16±0.93)×10-3 Pa s for extracted cytoplasm with DNA, (2.73±0.84)×10-3 Pa s for extracted cytoplasm without DNA, (1.95±0.72)×10-3 Pa s for the feeding buffer with polyethylene glycol, and (1.21±0.31)×10-3 Pa s for feeding buffer without polyethylene glycol. These results establish a procedure for determining the viscosity from small volumes of fluid, potentially allowing optimization of the viscosity of the media used for cell-free protein expression to maximize protein yield. | Morris, Jonathan Rowedder, Blake Smith, Nicholas | Morris, Jonathan | Rowedder, Blake | Smith, Nicholas | 1160 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_ViscosityofCellularMediums/FinalReport.html | |||
| 2011-05-06 00:00:00 | Acoustic | Band Structure of a Periodic Sonic Crystal | The band structure of a sonic crystal formed by an aluminum air duct with periodic properties is investigated experimentally. This will be done propagating acoustic waves from 500 to 5000Hz through the crystal and measuring gain as a function of frequency. The crystal structure is created by repeating uniform sections and scatterers that form an isotropic array of cells that determine the periodicity. This structure creates a waveguide that exhibits pass bands and stop bands whose wave solution is defined by Bloch wave theory. This results in a dispersion relation providing predictions for the locations of these bands. The goal of this experiment is to show the agreement of experimental data with these predictions as the dimensions of the crystal structure are varied. The data was found to agree with Bloch wave theory; however, the data taken was not fully consistent with the predicted values. More specifically, the stop band dependent on the resonance of the scatterer exhibited high disagreement for all configurations measured. | Deluca, Nicholas Hruby, Matthew | Deluca, Nicholas | Hruby, Matthew | 1170 | File Cabinet | http://mxp.physics.umn.edu/s11/Projects/S11_SonicBandGap/ | ||||
| 2010-05-07 00:00:00 | Cosmic Ray Experiments | Proportional Tube Array to Detect Cosmic Ray Angular Distribution | We build a set of proportional tubes placed into vertically separated arrays to act as a cosmic ray telescope. The tubes are tested to show capability in the detection of such rays along with their angular distribution of cosmic ray flux with a higher resolution than previous experiments that used plastic scintillator paddles. Although the proportional tubes can perform inconsistently due to lab environment and nearby tube interference, these tubes provide an inexpensive and easily constructed apparatus with the potential to detect cosmic rays. | Mulligan, Brian Planer, Michael | Mulligan, Brian | Planer, Michael | 1010 | File Cabinet | |||||
| 2010-05-07 00:00:00 | Cosmic Ray Experiments | Mean Muon Lifetime and its Electron Decay Energy Spectrum Using Liquid Scintillators | In this experiment, we measured the mean lifetime t of cosmic ray muons as they traveled through our detector. We also attempted to measure the mass of the muon, which is known to be 105.6 MeV/c2, by measuring its electron decay energy spectrum. We used a container partially full of liquid scintillator as the body of our detector where muons were absorbed and decayed, producing light that could be detected by the photomultiplier tube submerged in the liquid scintillator. The mean muon lifetime was found to be 2.127 ± 0.074 µs, which is within one standard deviation from the published value of 2.197 ± 0.001 µs. | Dhital, Valerie Hakimi, Sahel | Dhital, Valerie | Hakimi, Sahel | 1011 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_MuonLifeTimeEnergy/ | ||||
| 2010-05-07 00:00:00 | Cosmic Ray Experiments | Sky Survey and Angular Dispersion of Cosmic Rays | This experiment attempted to detect and map spatial anisotropies in the cosmic ray flux incident in the upper atmosphere. A pair of vertically stacked plastic scintillator paddles was used to detect coincidence events as muons produced in cosmic ray particle showers passed through the apparatus. Varying the inclination of the apparatus from vertical in the north-south plane and allowing the earth to rotate for 24 hours allowed us to measure the muon flux in bands on the sky ranging from 33.3 degrees south inclination to 33.3 degrees north inclination. We did not find any spatial anisotropy in the regions of the sky that we measured. | Crosby, Brian Reeves, Katherine | Crosby, Brian | Reeves, Katherine | 1012 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_CosmicRaySurvey/ | ||||
| 2010-05-07 00:00:00 | Cosmic Ray Experiments | Polarization of Cosmic Ray Muons | An experiment was performed to measure the polarization of cosmic ray muons with the purpose of studying parity violation. Positive and negative muons stopped in copper and aluminum (non-depolarizing) targets, as well as a glass (depolarizing) target, decay into positrons and electrons, respectively, which can be detected in plastic scintillators placed above and below the targets. Polarization measurements were not successful, but equipment testing yielded polonium half-life measurements within a standard deviation of the accepted value for both qVts, and a mean muon lifetime measurement of 2.2 ± 0.1µsec with a PCI timer card, which is accurate to within 0.1% of the accepted value. The results suggest further investigation of the equipment viability is needed before accurate polarization measurements can be made, specifically the logic circuit, scintillators and PMTs. | Kaardal, Joel Martin, Peter | Kaardal, Joel | Martin, Peter | 1013 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_MuonPolarization/ | ||||
| 2010-05-07 00:00:00 | Cosmic Ray Experiments | A Measurement of the Angular Distribution of Cosmic Ray Muons Using a Cloud Chamber | This experiment measured the polar angular distribution of cosmic ray muons. A camera and a trigger system were used to photograph the tracks muons produced in a cloud chamber. Their angle with respect to geographical north was then extracted from the images via a Hough transform. The use of a cloud chamber provided a high angular resolution of ±2o. Fitting a distribution to the data produced a reduced ?2 of 1.3312, which had an 11.3% probability of happening by chance. | Granstrom-Arndt, Chris Prestegard, Tanner | Granstrom-Arndt, Chris | Prestegard, Tanner | 1014 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_CloudChamber/ | ||||
| 2010-05-07 00:00:00 | Condensed Matter Physics | Density as a Function of Temperature in Liquid 4He | Our objective is to measure the temperature at which the density of the superfluid 4He is maximized. By utilizing a specially designed capacitor that is submerged in liquid helium, we will measure the capacitance as a function of temperature from (1.85-2.35)K. This capacitance reading can be converted into density by the use of the Clausius-Mossotti relation. Our maximum density occurred at (2.1784 ± 0.0012)K with a value of (0.14612 ± 0.00003) g/cm3. | Nuss, Michael Sachdeva, Dhruv | Nuss, Michael | Sachdeva, Dhruv | 1030 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_DensityofLiquidHe/ | ||||
| 2010-05-07 00:00:00 | Condensed Matter Physics | Second Sound in Liquid He II | The purpose of this experiment is to find the temperature dependence of second sound near T?. We found the velocity of the observed waves by driving the waves at a range of frequencies and looking for resonance in two different length chambers, from 1.4K to T?. | Fuglsby, Jason Nixon, Matthew | Fuglsby, Jason | Nixon, Matthew | 1031 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_LiquidHeSound/ | ||||
| 2010-05-07 00:00:00 | Condensed Matter Physics | Josephson Effect | The current-voltage relationship of Niobium-Aluminum oxide Josephson junctions of two sizes were characterized with no magnetic field applied. The critical temperature the Niobium was determined to be 8.75 ± 0.05 K from the characterization of the second junction, 9s from the expected value of 9.2 K. Magnetic fields were applied to both junctions at various strengths perpendicular to the junction's current flow, evaluating the resulting maximum supercurrent through the junction as a function of magnetic ux. From this characterization, the magnetic flux quantum f0 was determined to be (5.4 ± 1.6) ×10-15 Wb from the small junction, and (6.76 ± 0.95)×10-16 Wb from the medium junction. These measurements are 2.1s and 14.6s, respectively, from the expected value for f0 of 2.07×10-15 Wb. | Maunu, Ryan Vig, Sean | Maunu, Ryan | Vig, Sean | 1032 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_JosephsonEffect/ | ||||
| 2010-05-07 00:00:00 | Condensed Matter Physics | Magnetic Birefringence in the Liquid Crystal 5CB | We measured the magnetic and temperature dependence of induced birefringence in the liquid crystal 4-cyano-4?-n-pentylbiphenyl (5CB) above its isotropic-nematic phase transition temperature Tc. We found the birefringence was approximately proportional to the square of the magnetic field and inversely proportional to the temperature. We determined the difference between Tc and T*, the minimum supercooling temperature, to be 1.5 ± 0.2°C, which differs from a previous experimental value of 1.84 ± 0.15°C by 2 standard deviations. We also determined the constant to be (2.85 ± 0.01)x105 Jm-3°C-1, which differs from the previous experimental value of (1.4 ± 0.3)x105 Jm-3°C-1 by 70 standard deviations. The most significant sources of error were the uncertainty in the wavelength of the laser, uncertainties due to temperature fluctuations, and uncertainties in the measured magnetic field. | Brehm, Joshua Glass, Brian Krogstad, Molly | Brehm, Joshua | Glass, Brian | Krogstad, Molly | 1033 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_BirefringenceinLiquidXtals/ | |||
| 2010-05-07 00:00:00 | Condensed Matter Physics | Resistivity and Magnetic AC Susceptibility of La1-xSrxCoO3 | We measured the resistivity and magnetic susceptibility of two differently doped samples of La1-xSrxCoO3 (LSCO), and observed its magnetic phase transitions as a function of temperature. Using samples constructed by the previous MXP group of Buettner and Olson in Spring 2009 we took measurements while the system was warmed as opposed to measuring while the system cools as was originally done. We believed this method would allow us to better control and stabilize the temperature of the sample. However, we were not able to achieve temperature stability as we had hoped. We did verify that La1-xSrxCoO3does experience a metal-insulator transition (MIT) between .09 and .5 doping. Also, due to inconsistent phase transition temperatures, we believe at least one of our samples was incorrectly characterized to begin with. | Kuehler, Christopher Myers, Johnny | Kuehler, Christopher | Myers, Johnny | 1034 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_HTCSuperconductors/ | ||||
| 2010-05-07 00:00:00 | Optics | Light Scattering Due to Brownian Motion | This project investigated the intensity of scattered light and its relationship with the diameter of particles suspended in a fluid experiencing Brownian motion. The focus was on measuring multiple scattering angles, of which we chose 30°, 60°, and 120°, and comparing the accuracy and precision of the various angles. The experimentally measured diameter of the spheres was compared to the manufacturer?s specified diameter of 209nm and 480 nm. For spheres of diameter 209nm, the best values obtained were 224 ± 15 nm, 213 ± 7 nm, and 235 ± 6 nm for scattering angles of 30°, 60°, and 120°, respectively. For sphere of diameter 480 nm, the best values obtained were 334 ± 22 nm, 426 ± 14 nm, and 557 ± 6 nm for scattering angles of 30°, 60°, and 120°, respectively. | Johnson, Anne Stevens, Tanner | Johnson, Anne | Stevens, Tanner | 1050 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_LightScattering | ||||
| 2010-05-07 00:00:00 | Optics | Optical Tweezers | An optical tweezers is constructed using a 20mW HeNe laser and a 1.25 NA microscope objective. The tweezer's trap is modeled with Hooke's law, for displacements smaller than 1 µm. 6.02 µm polystyrene spheres are trapped by the tweezers and used to characterize the tweezer's stiffness by observing their displacement from the trap center when the solution is given a velocity of up to 10 µm/s relative to the trapped sphere. The trap's stiffness is found to be 20 ? 12 pN/µm, and a maximum trapping force of 0.40 ± 0.05 pN is observed. Significant deviation from the Hookean model of the trap is found and described. | Peterson, Robert Thorstad, Eric | Peterson, Robert | Thorstad, Eric | 1051 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_OpticalTweezers/ | ||||
| 2010-05-07 00:00:00 | Optics | Holographic Double Exposure Interferometry | The objective of this experiment was to determine Young?s modulus for brass and stainless Steel using double-exposure interferometry. We calculated Young?s Modulus for brass to be 107.33±1.11 Gpa and Stainless Steel to be 198.47±5.8 Gpa. | Dang, Tien Je, Sanghyun | Dang, Tien | Je, Sanghyun | 1052 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_Hologram/ | ||||
| 2010-05-07 00:00:00 | Optics | Saturated Absorption of Rubidium Using a Diode Cavity Laser | A diode laser was used to observe the absorption spectrum of rubidium's valence electrons. A saturated absorption apparatus was used through optical pumping to resolve more specific nuclear magnetic moments within these electronic states. | Behrman, Keith Kinnischtzke, Laura | Behrman, Keith | Kinnischtzke, Laura | 1053 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_HyperfineSplitting/ | ||||
| 2010-05-07 00:00:00 | Optics | Fractional Polarization as a Function of Scattering Angle in a Simulated Atmosphere | Measuring polarization due to scattering off suspended particles provides a unique tool for the study of planetary atmospheres. It is also commonly used to determine the size and shape of particles in liquid suspension. We measured the fractional polarization caused by scattering light off particles at different scattering angles. By using particles of a reported average size, our experiment explores the usefulness of this technique for determining the size ranges of suspended particles in situations where the particles' size is unknown or not easily estimated by other means. Theory and a computer model of the degree of polarization due to Rayleigh scattering and/or Mie scattering allowed us to estimate the size range of the scattering particles based upon their manifesting one or both types of scattering. | Shenoy, Dinesh Voltin, Jesse | Shenoy, Dinesh | Voltin, Jesse | 1054 | File Cabinet | |||||
| 2010-05-07 00:00:00 | Optics | Optical Polarization of the Crab Nebula | In this experiment we measured the polarization of the Crab nebula in the optical spectrum. Our goal was to reproduce observations made by Dr W. Baade and the 100 inch Hooker telescope on Mt. Wilson. Although we utilized a much smaller telescope, with the advent of modern CCD's and digital image processing we were able to achieve results in agreement with Dr Baade. Using a 6 inch telescope, CCD, and a simple polarizing filter we measured the polarization of the Crab Nebula to be between 30 and 60% on average. As polarization in an astronomical source rarely exceeds a few percent, 30% and up is far too high to be produced by normal astronomical sources polarized by the interstellar medium. We can conclude by the high degree of polarization that the emission source of the Crab Nebula is synchrotron radiation produced by the pulsar. | Ely, Justin Vouk, Lisa | Ely, Justin | Vouk, Lisa | 1055 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_PolarizationCrabNebula/ | ||||
| 2010-05-07 00:00:00 | Acoustic | Sonic Band Gap in a Periodic Waveguide | In this experiment, we investigate sonic band gaps in a waveguide with periodic, abrupt variations in bore width, particularly the manner in which the spacing and depth of these ?sonic crystals? affects the frequency range of the band gap. This is tested by driving a long rectangular aluminum waveguide with sound waves of frequencies between 500 and 5000 Hz and observing the transmittance at various points along the waveguide. The behavior of the band gap is found to correspond qualitatively to the predictions of the Bloch wave model, particularly in the behavior of band gaps caused by resonance of the sonic crystals, though our equipment was not sophisticated enough to make a quantitative confirmation. | Barthel, Joseph Copenhaver, Ben | Barthel, Joseph | Copenhaver, Ben | 1070 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_SonicBandgap/ | ||||
| 2010-05-07 00:00:00 | Nonlinear Systems | Dynamics of Knots in Vibrated Granular Chains | In this experiment, the unknotting behavior of five prime knots in vertically vibrated granular chains is observed as an extension of previous investigations with trefoil knots. This provides a simplified model of the complex dynamical behavior which entangled polymers undergo. Knot theory and polymer dynamics are applied to examine the opening times of entangled steel ball chains with five crossings as they are vibrated on a plate. The unknotting time distributions of the two 5 knot configurations are shown to follow a universal scaling curve, indicative of a single unknotting behavior independent of chain length. | Gebrehiwet, Simon Santiago, Jessica | Gebrehiwet, Simon | Santiago, Jessica | 1080 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_GranularChains/ | ||||
| 2010-05-07 00:00:00 | Misc | Conductive Inkjet Printing | A consumer-grade inkjet printer was modified to deposit sheets of conductive ink onto laserjet transparency substrate. Sheet length, width, and thickness varied from 5-10mm, 1-5mm, and 1-5 layers, respectively. Sheet resistance was measured by four-terminal technique at several current levels, varying from 0.1mA to 10mA. Sheet resistance was expected to depend inversely on thickness and be independent of length and width. Results are consistent with an inverse dependence on thickness, but significant dependence on both length and width of the sheet were found, suggesting a geometry or percolation effect. | Brown, Steve Howell, Nick | Brown, Steve | Howell, Nick | 1090 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_BubbleJet | ||||
| 2010-05-07 00:00:00 | Misc | Grating-coupled Microwave Transmission Through Subwavelength Apertures | The purpose of our experiment was to determine the surface plasmon grating-coupled resonant frequencies of microwaves incident on a subwavelength aperture surrounded by periodic corrugations. Microwaves in a frequency range 1.8-4.2 GHz were sent through a circular aperture of radius, r = (1.27 ± 0.005) cm, in order to determine the frequency that resonates with the aperture and surrounding aluminum grating structure. We aimed to further confirm resonance depends on the corrugation pattern and aperture size by expanding work done by other groups in the 10-18 GHz range to a lower frequency range 1.8-4.2 GHz. The final results of our analysis yield data with resonance at 2.4 GHz and 3.6 GHz, but we cannot definitively conclude that the resonance is caused by the coupling of surface plasmon modes to the grating structure because resonance also occurs in our non-corrugated aperture structure. | Dorroh, Daniel Hinkle, Alicia | Dorroh, Daniel | Hinkle, Alicia | 1091 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_MicrowaveTransmission/ | ||||
| 2010-05-07 00:00:00 | Misc | Dipole Moment Change Between Electronic States of Coumarin 102 | This experiment attempted to measure the change in dipole moment between the ground and excited state of Coumarin 102 (C102). The measurements were made using methods of modern spectroscopy (see Apparatus and Data Collection). Knowing the change in dipole moment allows one to use C102 to determine how much a solvent reorients when placed in an electric field. The change in dipole moment was measured to be 5.6±1.6D, which is within 0.4s of the literature value. | Grasse, Cole | Grasse, Cole | 1092 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_Solvations/ | |||||
| 2010-05-07 00:00:00 | Misc | Driven Foucault Pendulum | We construct and operate a small-scale electromagnetically driven Foucault pendulum with a 1.3 m wire and a 5 kg iron bob. While heavily based upon H.R. Crane's design, we incorporate a 2-dimensional hall sensor to continuously record the pendulum's precession. Our most stable data run yields a turning rate of 10.3o/hr with a standard deviation of about 1.1o/hour, lying within one sigma of the expected hourly rate of 10.63o/hour. We also investigate the effects of altering various system parameters. | Geddes, James Schroeder, Martin | Geddes, James | Schroeder, Martin | 1093 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_Foucault/ | ||||
| 2010-05-07 00:00:00 | Misc | Maintaining Unstable Equilibrium of an Inverted Pendulum | The purpose of our project was to create a control system to balance a pendulum in unstable equilibrium. This was achieved using a Proportional Integral Derivative (PID) controller to compensate for a continuous gravitational torque, thereby keeping the pendulum aligned with the vertical axis. Our project implemented this control algorithm differently from the approach of past groups, as well as measured the constants of the PID equation using a more systematic method than previously. In this way, we hoped to develop a more accurate theory for the pendulum control system. By analyzing the Root Mean Square of the vertical angle over two minute intervals, we found a region of values for these constants that lead to stability in the system. Using the Ziegler-Nichols method of parameter tuning for the PID algorithm, we found optimal values for creating unstable equilibrium in the system (KP = 1.50, KI = 0.43 s. KD = 0.11 s ) which lie in this region of stability. | Julin, Andy Weyandt, Dan | Julin, Andy | Weyandt, Dan | 1094 | File Cabinet | http://mxp.physics.umn.edu/s10/projects/S10_Pendulum/ | ||||
| 2009-05-06 00:00:00 | Condensed Matter Physics | Apparatus for Characterizing Tunable Infrared Detecting and Emitting Micro Cantilever Heterostructures | Using the Transfer Matrix Method, two separate Indium Gallium Arsenide (In0.53Ga0.47As)/ Indium Phosphide (InP) heterostructures were analyzed to calculate bound state energy levels within the respective quantum well structures. From these calculations, effective bandgap energies were calculated for various transitions in each structure. These calculated transition energies were then compared to the observed photoluminescence spectrum for each heterostructure. The result of this analysis demonstrates considerable agreement between theoretical expectation and observed phenomenon. For calculated transition energies of 1.10eV, 0.90eV, and 0.81eV, photoluminescence peaks of 1.09eV, 0.88eV, and 0.80eV respectively were observed. | Anderson, Brady | Anderson, Brady | 931 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_TunableIRHetroStructure/ | |||||
| 2009-05-06 00:00:00 | Nonlinear Systems | Chaotic Circuit | In this experiment we used a circuit design proposed in a paper written by Professor Clint Sprott of the University of Wisconsin to study the parametric reliant response of a circuit which models a third order differential equation known to produce chaotic results. From this circuit we acquired bifurcation plots, frequency space plots, and an experimental measurement of Feigenbaum's constant, which we found to be 4.682 ± 0.136. We also tested the possibility of using this circuit as a means of chaotic encrypted communication, which we found to be possible although the signal produced by this circuit, in a purely chaotic regime, proved to be far from white noise and would not be an ideal choice for masking an input signal. | Lewis, JeremyJepson, Roger | Lewis, Jeremy | Jepson, Roger | 980 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_ChaoticCircuit/ | ||||
| 2009-05-06 00:00:00 | Condensed Matter Physics | Density of He as a Function of Temperature | In this experiment we measured the density of 4He as a function of temperature, near the lambda point of 2.17K, in order to determine the temperature at which the density is maximized. We used a capacitor to measure the density of the Helium in the temperature range of 1.6K to 2.6K. Our measured density maximum occurred at 2.167±0.004K which is 2.25 standard deviations away from the accepted value of 2.176K. | Oestreich, MitchThiede, Nicholas | Oestreich, Mitch | Thiede, Nicholas | 930 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_HeDensity/ | ||||
| 2009-05-06 00:00:00 | Optics | Determination of Surface State Transition Temperatures and Electric Polarization in thin Liquid Crystal Films using Depolarized Reflected Light Microscopy | In this experiment, our purpose is to study the total number of surface states and electric polarization of each surface state associate with each layer number of thin freestanding liquid crystal films by employing the Depolarized Reflected Light Microscopy. The compound 12OF1M7 was used for this experiment. A series of films are studied from 6 layers up to 12 layers. Our observed results agree with work done by B.K. McCoy and LiDong Pan. | Moths, BrianZhang, Can | Moths, Brian | Zhang, Can | 951 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_LiquidXTal/ | ||||
| 2009-05-06 00:00:00 | Optics | Measurement of Hydrodynamic Diameter of Polystyrene Spheres by Dynamic Light Scattering | We measured the hydrodynamic diameter of 240nm, 340nm, 500nm, and 1020nm polystyrene spheres by utilizing the dynamic light scattering technique. Laser light was incident on a dilute solution of monodisperse spheres and scattered about some range of angles. Fluctuations in the intensity of scattered light were observed in the frequency domain. Analysis of frequency spectra resulting from 90° scattering yielded hydrodynamic diameters of 170 ± 15 nm, 230 ± 20 nm, 480 ± 42 nm, and 1110 ± 98 nm, respectively. These diameters differ from the manufacturer quoted values by 4.7, 5.5, 0.48, and 0.92 standard deviations. The measured dependence of the dynamic light scattering technique on scattering angle was not consistent with the predicted trend. | Anderberg, AnthonyMirman, Nathan | Anderberg, Anthony | Mirman, Nathan | 950 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_DynamicLightScattering/ | ||||
| 2009-05-06 00:00:00 | Particle Experiments | Electron Pair Production and Annihilation Phenomena | Pair production events were detected and cross sections for event probabilities were measured and verified for several target absorber materials. In this experiment a cobalt [60] source provided gamma rays above one MeV that interacted with the nuclei of the target absorber producing pair events. The detection of pair events was made using a coincidence detector that simultaneously detected the two annihilation gamma rays from the positrons produced in the process. This technique amplified the pair event energy range of the spectrum that made it possible to detect the production peak above the background. | Peterson, Adam | Peterson, Adam | 920 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_ElectronPairProduction/ | |||||
| 2009-05-06 00:00:00 | Cosmic Ray Experiments | Energy of Muons | The mean velocity of cosmic ray muons was measured by means of a timing measurement of the interval for the muon to travel between upper and lower paddles of a scintillator telescope. A qVt multichannel analyzer was used to measure the flight times corresponding to varying paddle separations to an uncertainty of about ten picoseconds, and these flight times were plotted versus separation distance to extract an average velocity ? the slope of a linear least-squares fit. The final velocity obtained was (2.83 +/- .14) x 10^8 m/sec. This is just over one s away from the value obtained by Liu of (2.98 +/- .25) x 10^8 m/sec. | Ahrens, MitchBobula, Jake | Ahrens, Mitch | Bobula, Jake | 910 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_MuonEnergy/ | ||||
| 2009-05-06 00:00:00 | Cosmic Ray Experiments | Radiation as a Function of Altitude Using High-Altitude Ballooning | In this experiment we used high-altitude ballooning to study the effects of altitude on radiation detected by a Geiger counter. From our data we calculated the absorption length of air, or the distance into air at which the probability has dropped to 1/e that a particle has not been absorbed. We calculated the absorption length to be (192±4)g/cm2, which is within 18 s of the accepted value 120 g/cm2 for dry air. This discrepancy between our measured value and the accepted value can be accounted for due to variances in air moisture and composition. | Fleischhacker, AmyLaHaye, Nicole | Fleischhacker, Amy | LaHaye, Nicole | 911 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_HighAltitudeBalloon/ | ||||
| 2009-05-06 00:00:00 | Condensed Matter Physics | Josephson Junctions | We examine two phenomena in Josephson junctions, the DC effect and the Fraunhofer diffraction pattern of critical current. From the DC effect we can calculate the critical temperature of our niobium superconductors by examining the quasi-particle tunneling. We observed a critical temperature of 9.21 ± .19 K, which is in agreement with the accepted value of 9.2 K. The Fraunhofer pattern allows us to calculate one magnetic flux quantum, which we found to be 1.40 ± .89 x10-16 Tm2. This is 21 standard deviations from the accepted value of 2.07 x10-15 Tm2, suggesting that the observed diffraction pattern consists of serious systematic errors. | Bryan, MatthewMattsen, Jeff | Bryan, Matthew | Mattsen, Jeff | 932 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_ShapiroSteps/ | ||||
| 2009-05-06 00:00:00 | Condensed Matter Physics | Magnetic Force Microscopy | A macroscopic model of a magnetic force microscope (MFM) is constructed and its interactions with magnetic and conductive materials are characterized by means of the phase-controlled oscillator method. The scale of the apparatus allows us to circumvent the difficulty inherent in testing imaging models using the conventional MFM. We found that for sufficiently large lift heights, the change in resonant frequency is proportional to the magnetic force gradient. | Hennen, Tyler | Hennen, Tyler | 933 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_MagneticForceMicroscopy/ | |||||
| 2009-05-06 00:00:00 | Condensed Matter Physics | Magnetic Susceptibility of Metals | The AC magnetic susceptibility of gadolinium was measured as a function of temperature from 273 K to 350 K. From the AC magnetic susceptibility data for gadolinium, the Curie-Weiss law was used to determine the Curie temperature. The Curie temperature of gadolinium was measured to be 291±1 K. This value is 2.60s away from the literature value of 293.6 K. | Brecht, Teresa Cowman, Christina | Brecht, Teresa | Cowman, Christina | 934 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_MagneticSusceptibility/ | ||||
| 2009-05-06 00:00:00 | Atomic Physics | MRI | The goal of this experiment was to examine a method of signal gathering in one-dimensional magnetic resonance imaging. Different materials have a different characteristic time known as T2 that affects the amount of signal possible to gather from them; this T2 property was varied between imaging scans. Specifically, we were examining what is commonly referred to as short T2 times, which fall in the few ms to hundred µs range. The amount of image signal we obtained was plotted against the T2 values, to observe whether or not it matched our predictions; indeed, our data followed the trends we expected it to. In addition, we determined that the shortest T2 value this method is capable of accurately producing images lies somewhere between 800 µs and 1.5 ms. | Harris, Robert | Harris, Robert | 940 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_MRI/ | |||||
| 2009-05-06 00:00:00 | Atomic Physics | NMR | We used pulsed nuclear magnetic resonance spectroscopy to measure the spin-lattice and spin-spin relaxation times in various mixtures of glycerin and water. Also by using pulsed nuclear magnetic resonance spectroscopy we measured the chemical shift in fluorine. | Olmschenk, Greg Poitra, Ryan | Olmschenk, Greg | Poitra, Ryan | 941 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_NMR/ | ||||
| 2009-05-06 00:00:00 | Atomic Physics | Optical Pumping | Placing a sample of 87Rb was placed in an external field and optically pumped into a specific hyperfine state. Applying an oscillating magnetic field perpendicular to the external magnetic field causes transitions between hyperfine states the system could be unpumped. By noting the frequency of oscillating magnetic field at which these transitions occur for a given external magnetic field strength, the transition energies between hyperfine states can be found as a function of external magnetic field strength. These transition energies can be compared to those predicted by the Breit- Rabi equation. This was done, with a reduced Chi Squared of 1.1. | Kirkland, Kris | Kirkland, Kris | 942 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_OpticalPumping/ | |||||
| 2009-05-06 00:00:00 | Condensed Matter Physics | Perovskite Magnetic Oxide | Two compositions of La1-xSrxCoO3 (x = 0.09 and x = 0.50) have been characterized by the temperature dependence of their resistivity and AC magnetic susceptibility. We confirm our expectation that the material undergoes both magnetic phase and metal-insulator transitions at a doping ratio somewhere in the range of 0.09 < x < 0.50. | Buettner, Dan Olson, Nick | Buettner, Dan | Olson, Nick | 935 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_Perovskite/ | ||||
| 2009-05-06 00:00:00 | Condensed Matter Physics | Persistent Photoconductivity | The inclusion of nanocrystalline silicon in thin films of hydrogenated amorphous silicon (thereby forming a/nc-Si:H) has shown some promise in decreasing or even reversing the Staebler-Wronski Effect (SWE), and could lead to more efficient thin film solar cells. The opposite of SWE is known as persistent photoconductivity (PPC). In this experiment we measured dark conductivity s in a/nc-Si:H versus light exposure time t, and found that s = A t^ß(T), where A is a proportionality constant, T is the temperature, and ß is an intrinsic quality of the film. We did not have enough data to determine the functional form of ß(T). | Razieli, Zvie Stark, David | Razieli, Zvie | Stark, David | 936 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_PersistentPhotoconductivity/ | ||||
| 2009-05-06 00:00:00 | Particle Experiments | Radioactivity in Rainwater | Previous studies showed an increase of background radioactivity during periods of rainfall. Utilizing a slightly different setup, we measured rain precipitation rate and ß decay rates at several different elevations and environments. We found that there did appear to be a correlation between these two rates, but that there were too many variables involved to accurately use Geiger counters to measure rain precipitation rates. We found that radiation from rain decreased with altitude, and that an optimal height above the surface between 2m and 20m gave the best correlation of data. | Johnson, Mark Myers, Kirby | Johnson, Mark | Myers, Kirby | 921 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_RadioactivityInRainwater/ | ||||
| 2009-05-06 00:00:00 | Condensed Matter Physics | Fourth Sound of Liquid Helium | Liquid helium, when below what is called the lambda temperature, undergoes a phase transition and becomes a superfluid, a state where the viscosity is almost zero (about 10^11 times lower than that of normal liquid helium). We investigated the temperature dependence of the speed of sound in superfluid 4He, showing that the speed goes to zero as the temperature approaches the lambda temperature from below. For 4He, the lambda temperature is 2.17 K, and our temperatures ranged from just below lambda temperature down to 1.5 K. | Moore, Ian Sawhney, Michael | Moore, Ian | Sawhney, Michael | 937 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_LiquidHeSound/ | ||||
| 2009-05-06 00:00:00 | Condensed Matter Physics | Spin Resonance | This experiment measured the anisotropic resistance (AMR) as well as electrically detecting ferromagnetic resonance (FMR) of a Permalloy strip. This experiment used photovoltage to probe the FMR of a Permalloy strip. The line shape of the photovoltage can be used to determine information about the FMR. The AMR of the sample is: R(?) = (95.4 ? .2) + (.946 ? .002) cos(?) ohms. The Gilbert damping coefficient was calculated to be: 0.0062?0.0095.. The photovoltage line shape was also decomposed into the asymmetric and symmetric parts. | Malm, Erik Olander, Matt | Malm, Erik | Olander, Matt | 938 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_SpinResonance/ | ||||
| 2009-05-06 00:00:00 | Condensed Matter Physics | SQUIDs | By measuring the voltage vs. magnetic field curve for individual SQUIDS we hope to show that SQUIDs produce a sinusoidal curve with a period of a flux quanta. From this we also hoped to show the optimal bias current and the best lock in point for a SQUID. The last two items this project failed to show but the reasons for the failure are known and can be corrected in the future. | McNamara, Ryan Spillane, Mick | McNamara, Ryan | Spillane, Mick | 939 | File Cabinet | http://mxp.physics.umn.edu/s09/Projects/S09_SQUID/ | ||||
| 2008-05-05 00:00:00 | Acoustic | Acoustophoresis | High frequency acoustic waves are used to motivate particle separation in water. The intended results weren?t achieved, but a verification of acoustic radiative forces on particles was observed. The difficulties encountered involved how the standing acoustic wave was to be produced, and the size of the apparatus. The shapes of the transducer and the acoustic resonator should have been matched better. Using water, the device was made for an 80kHz standing wave, but this scale was too large for the way the device was driven. | Anderson, Jonathan Howard, Brian | Anderson, Jonathan | Howard, Brian | 870 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_Acoustophoresis/ | ||||
| 2008-05-05 00:00:00 | Cosmic Ray Experiments | Measure of the Angular Distribution of Cosmic Ray Muons | In this experiment we measure the angular distribution of cosmic ray muons using a paired-scintillator telescope and fit the data against several possible distributions in order to show that it best fits the theoretical prediction of cos2(?). The reduced ?2 values of fits against cos, cos2, and cos3 were found to be 11.9, 0.8, and 4.7, respectively. From this, it is clear that cos2 is the best fit to the data. | Barnes, Richard Malm, Erik | Barnes, Richard | Malm, Erik | 810 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_AngularDistr | ||||
| 2008-05-05 00:00:00 | Condensed Matter Physics | Anisotropic Magnetoresistance and Domain Wall Resistance in Epitaxial Fe/GaAs | We quantitatively characterize electrical transport properties of some Schottky-doped and semi-insulating epitaxial Fe/GaAs thin films between T = 300 K and T = 10 K, observing a temperature dependence in the magnitude and the mechanism of the anisotropic magnetoresistance. In the Schottky-doped film we observe an anomalous fourth order anisotropy in the magnetoresistance and quantify its magnitude. We also design a nanowire structure using a notch as a pinning site to trap a domain wall and attempt to measure its electrical resistance, but found an electrical short independent of excitation current. | Christle, David | Christle, David | 835 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_AnisotropicMagnetoResistance | |||||
| 2008-05-05 00:00:00 | Misc | Bolometirc Detection of He Pulses | In this paper we report the successful room temperature testing of a feedback circuit designed to keep a cryogenic bolometer in its transition from a superconducting state to a normal operating state. The transition region is characterized by dramatic changes in the bolometer?s resistance due to very small changes in temperature; this allows the bolometer to be extremely useful in detecting incident low energy atoms. Due to multiple dilution refrigerator failures, a cryogenic test of the circuit was unable to be accomplished. The inability to maintain cryogenic temperatures for long periods of time did, however, allow a measurement of transition region of new bolometers. The new transition region of these bolometers is described at a temperature of 510 mK and a bolometer resistance of 3 O. | Cook, David Schofield, Andy | Cook, David | Schofield, Andy | 891 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_HePulse | ||||
| 2008-05-05 00:00:00 | Condensed Matter Physics | A Determination of the Curie Temperature of Gadolinium | The goal of this experiment was to determine the Curie temperature (TC) of Gadolinium. The Curie temperature is the temperature at which a ferromagnetic metal under goes a state change from ferromagnetic to paramagnetic behavior. We observe this state change by suspending a sample rod of Gd in a uniform external magnetic field. After perturbation, we measured how the natural oscillation frequency changed with temperature. The Curie temperature was found to be (20.4 ± 0.1 ± 1.0)°C which compares to the published value of (19.5 ± 0.5±)°C. | Cram, Alex Dunham, Marc | Cram, Alex | Dunham, Marc | 833 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_CurieTempGdTorsion | ||||
| 2008-05-05 00:00:00 | Condensed Matter Physics | Inductive Measurement of the Curie Temperature of Gadolinium | We measured the Curie temperature of gadolinium, TC, through a two -coil, AC inductive method, measuring gadolinium?s magnetic susceptibility as a function of temperature. We report TC as 19.55 ± 0.03°C. Although TC is not well defined in the literature, our result lies within the commonly listed range of 19-20°C. | Gleason, Sam Pieterick, Adam | Gleason, Sam | Pieterick, Adam | 834 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_CurieTempGdInduction | ||||
| 2008-05-05 00:00:00 | Condensed Matter Physics | Determination of the Diffusion Coefficient Between Two Miscible Fluids Using a Digital Camera | We measure the diffusion coefficient between corn syrup and water using a digital camera. We use an ultraviolet light source in a dark room to illuminate the corn syrup and record the result with a digital camera. We report (3.3±0.2)×10-6cm2/s for the diffusion coefficient of water and Karo syrup. This differs significantly from previously published results. | Moses, Charles | Moses, Charles | 836 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_DiffusionCoefficient | |||||
| 2008-05-05 00:00:00 | BioPhysics | Effect of an Electric Field on Cell-Free Gene Expression | Previous research conducted by James J. Greene suggests that transcription rates in gene expression systems can be increased by the application of 60 Hz electromagnetic waves. Using his work as a guideline, we set out to study the effects of 60 Hz electric fields on in vitro gene expression systems. We found that after a five minute application of the field, our protein marker signal declined, eventually returning to initial values over the course of several hours. | Ellis, Joshua Williams, Mathew | Ellis, Joshua | Williams, Mathew | 860 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_CellFreeGeneExpression | ||||
| 2008-05-05 00:00:00 | Cosmic Ray Experiments | Measurement of the Energy Distribution of Cosmic Muons | Cosmic muons are produced when a cosmic ray collides with an air molecule in the earth?s atmosphere. We measured the energy distribution of these cosmic-ray muons by counting how many had enough energy to penetrate different amounts of lead, up to a thickness of 150cm. Scintillator paddles coupled to photomultiplier tubes were used to detect the particles. We were able to measure up to 1.9MeV, and found the average muon energy to be 1.2±0.1GeV. | Kirkland, Kristopher Leonard, Katie | Kirkland, Kristopher | Leonard, Katie | 811 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_EDistributionCosmicMuons | ||||
| 2008-05-05 00:00:00 | Condensed Matter Physics | Electron Paramagnetic Resonance Studies of the Muscle Protein Myosin | Electron paramagnetic resonance was used to create absorption spectra of the muscle protein myosin. These spectra were analyzed and compared to Monte Carlo simulation to find a function to model the observed behavior. By fitting the absorption spectra with Gaussian polynomials, the distances between two unpaired electron sites were found to be (20.2 ± 0.3) Å with standard deviation (4.5 ± 2.3) Å and minimized ?² of 1.742 in the apo state, (17.0 ± 0.4) Å with standard deviation (15.1 ± 2.3) Å and minimized ?² of 4.220 in the actin-bound state, and (22.0 ± 0.3) Å with standard deviation (5.0 ± 1.8) Å and minimized ?² of 0.912 in the ADP VO3?bound state. | Kennedy, Daniel Preiwisch, Adam | Kennedy, Daniel | Preiwisch, Adam | 830 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_SkeletalMuscleProtein | ||||
| 2008-05-05 00:00:00 | Optics | Wavelength Dependence of the Verdet Constant in TGG and SF59 Utilizing an Alternating Magnetic Field | We attempted to utilize an alternating magnetic field technique to measure the Verdet constants of Terbium Gallium Garnet and SF59 Heavy Flint Glass. The AC field technique, when properly executed has the potential to provide more accurate measurements than does a DC field. However, our setup had systematic problems with pickup from the AC field that prevented us from detecting a signal. We briey utilized a DC field at the end of the semester to verify that the AC field caused the pickup. We were able to verify the TGG fit with this method, but our SF59 data was more consistent with the cited SF6 fit. Shortcomings are discussed and improvements for future work suggested. | Cheesbrough, Vanessa Muckenhirn, Craig | Cheesbrough, Vanessa | Muckenhirn, Craig | 851 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_FaradayEffect | ||||
| 2008-05-05 00:00:00 | Nonlinear Systems | Measuring Earth?s Angular Velocity Using a Magnetically Suspended Ball | The goal of this experiment is to measure the angular velocity of Earth. Using a computerized control system we were able to stably levitate a spinning paramagnetic stainless steel ball for 43 hours. The minimal-torque environment conserved the angular momentum of the ball which allows for a measurement of precession of the ball?s angular momentum vector; this is related to the angular velocity of Earth and our latitude on Earth. We were unable to observe any precession due to the non-uniformity of the ball?s mass distribution. | Radloff, Peter Svenkenson, Adam | Radloff, Peter | Svenkenson, Adam | 880 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_MagneticSuspension | ||||
| 2008-05-05 00:00:00 | Condensed Matter Physics | Determining the Effect of an Oscillating Magnetic Field on Aluminum and Copper | A pendulum apparatus was constructed to quantify the displacement of a non-ferromagnetic conducting sample when perturbed by an oscillating permanent magnet. The ratio of maximum displacement angles between materials was related to the ratio of material conductivities. The ratio of aluminum displacement to copper displacement was measured to be 0:63 +/- 0:01. The accepted value for the ratio of material conductivities is 0.634. | Hellerstedt, John Lorshbough, Dustin | Hellerstedt, John | Lorshbough, Dustin | 835 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_NonMagneticMaterials | ||||
| 2008-05-05 00:00:00 | Nonlinear Systems | Invert Pendulum Control | The goal of this experiment was to keep a pendulum that was mounted on a rotating arm upright by controlling the acceleration of the arm. Since this an unstable system, a proportional-integral-derivative (PID) controller was used. Experimentation was done to determine the parameters of the PID controller and to observe how these parameters were related to the physical system. After the pendulum could be balanced indefinitely, an additional function was added to the PID control that would swing the pendulum up from the stable equilibrium. Lastly, the potentiometer in the pendulum (used to find the angle of the pendulum) was made wireless with a voltage-to-frequency chip and a frequency-to-voltage chip. | Ritter, Lisa Koth, Karl | Ritter, Lisa | Koth, Karl | 881 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_InvPend | ||||
| 2008-05-05 00:00:00 | Condensed Matter Physics | Measurement of the Thermal Properties of Hydrogenated Amorphous Si in the mK Range | We measured the resistance as a function of temperature for three samples of hydrogenated amorphous silicon, each with a different level of hydrogen added to the silicon (20%, 16%, and 12% hydrogen). Our goal was to find which produced the best thermometer. | Erickson, James Rumney, Ashley | Erickson, James | Rumney, Ashley | 831 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_HydrogenatedAmorphousSi | ||||
| 2008-05-05 00:00:00 | Condensed Matter Physics | Thermal Conductivity and Diffusivity of Glass | We present an AC heating technique to measure the thermal conductivity and diffusivity of a glass microscope slide at 77K and 300K. The experiment uses a range of heating frequencies and temperatures for soda-lime glass. These results are promising yet inconclusive for the correct operating regimes were never met. | Behar, Ian Sherve, Andrew | Behar, Ian | Sherve, Andrew | 836 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_ThermalDiffusivityGlass | ||||
| 2008-05-05 00:00:00 | Acoustic | Measuring the Speed of Sound and Young's Modulus in Aluminum and Stainless Steel | We describe an experimental technique that takes advantage of standing waves driven at resonance frequencies to measure the speed of sound and determine Young's modulus for two materials, aluminum and stainless steel. We determined a value for Young's modulus of (7.6±0.2) x 1010 Pa and (28.2± 0.2) x 1010 Pa for aluminum and stainless steel, respectively. Both of these values are between three and four standard deviations away from the accepted values. | Bergquist, Brian Moore, Ian | Bergquist, Brian | Moore, Ian | 872 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_YoungsModulus | ||||
| 2008-05-05 00:00:00 | Optics | Modeling Thermal Expansion Using Double Exposure Holographic Interferometry | We measured the coefficients of linear thermal expansion (a) for copper and aluminum by utilizing double exposure holographic interferometry (DEHI). DEHI is a technique in which a hologram is exposed twice to a surface?once before and once after some distortion is made. The resulting interference patterns allow for measurement of these distortions accurately to within one wavelength of the light used when making the hologram. The accepted a values for copper and aluminum are 1.7 x 10-5 K-1 and 2.3 x 10-5 K-1, respectively. Using DEHI, we calculated a to be (2.0 ± 0.1) x 10-5 K-1 for copper, and (2.4 ± 0.2) x 10-5 K-1 for aluminum?presenting respective deviations of 3s and 0.5s from the accepted values. | Martin, Stephen Moe, Catherine | Martin, Stephen | Moe, Catherine | 850 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_ThermalExpansion | ||||
| 2008-05-05 00:00:00 | Atomic Physics | Pulsed NMR Relaxation of Shortening as a Function of Temperature | Using pulsed nuclear magnetic resonance, we measured the relaxation time constants T1 and T2 for vegetable shortening between temperatures of 25°C and 60°C. We found proportionality between temperature and both T1 and T2 over all measured temperatures. However, the constant of proportionality changes for T1 at about 35°C, and for T2 at 26°C and 28°C. These temperatures approach the freezing temperature for vegetable shortening of (31.5 ± 0.5)°C, so we theorize that deviations in viscosity and atomic spacing account for the changes in proportionality. | McCaffrey, Jesse Wilson, Justin | McCaffrey, Jesse | Wilson, Justin | 840 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_NMR | ||||
| 2008-05-05 00:00:00 | Cosmic Ray Experiments | Measurement of the Decoherence Curve of Cosmic Ray Muons using Silicon Photomultipliers | We design, build, and implement an apparatus that uses silicon photomultipliers to detect cosmic rays. We use the apparatus to measure the decoherence curve of cosmic ray muons. We then derive an energy distribution of primary cosmic ray particles from this measurement. Our results are in good agreement with previous experiment. | Eggert, Nicholas Weinberg, Matthew | Eggert, Nicholas | Weinberg, Matthew | 812 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_SiMultipliers | ||||
| 2008-05-05 00:00:00 | Cosmic Ray Experiments | Portable Cosmic Ray Observation Platform (P-CROP) | We underwent the task of designing and constructing a portable Geiger Muller tube based cosmic ray detector capable of functioning in the extreme conditions present in the upper atmosphere, and deploy it using a weather balloon to construct a model of the cosmic ray air showers present in the atmosphere. We were able to determine that the cosmic rays follow the general trend of a decrease in flux over the first three thousand feet, an increase in flux until a maximum is reached at approximately sixty-five thousand feet, and finally a decrease in flux as the balloon climbs beyond that to one hundred thousand feet. We found that the maximum flux of secondary particles occurs at 65000+/-5000 ft. | Lundquist, Michael Negrashov, Sergey | Lundquist, Michael | Negrashov, Sergey | 813 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_PortableCosmicRayObservationPlatform | ||||
| 2008-05-05 00:00:00 | Acoustic | Temperature Dependence of Light Emission Intensity of Single-Bubble Sonoluminescence in Water-Glycerin Solutions | The dependence of sonoluminescence intensity on solution temperature is measured and compared to theory which suggests an exponential decrease of intensity with increasing temperature. While a clear inverse relationship between intensity and temperature is found, the quality of an exponential fit is questionable. We found a reduced ?2 value of 22.4 for the exponential fit. Additionally, a linear fit to the data of intensity versus temperature was found to have a reduced ?2 value of 19.2, indicating no significant improvement of an exponential fit over a linear fit. | Fake, David Hausauer, Justin | Fake, David | Hausauer, Justin | 871 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_Sonoluminescence | ||||
| 2008-05-05 00:00:00 | Misc | Experiment to Measure the Sensitivity and Cohesion of Superconducting Quantum Interference Devices | The purpose of this experiment was to determine the sensitivity and cohesion of the voltage output of Superconducting Quantum Interference Devices as a response to changing magnetic flux. This experiment succeeded in measuring the resistance properties of resistors as a function of changing temperature and allowed us to verify the circuitry for use with measuring SQUIDs. This experiment also succeeded in testing the forward biased voltage of a 1N5282 diode as a response to changing temperature. This has potential use as an inexpensive three state temperature sensor for temperatures 4K , 77K, and to 300K (room temperature). Hold time for the apparatus was determined to be greater than 9 hours. This experiment failed in determining the sensitivity and cohesion of SQUIDs. | Legatt, Michael Riggs, Benjamin | Legatt, Michael | Riggs, Benjamin | 890 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_SQUID | ||||
| 2008-05-05 00:00:00 | Condensed Matter Physics | Velocity of Second Sound in He II | We measured the velocity of second sound in helium II as a function of temperature using resonance. Results were obtained between 1.4K and 2.17K (the ?-point) at saturation vapor pressure which matched previously published results within experimental uncertainty. | Fitch, Micah Kosowski, John | Fitch, Micah | Kosowski, John | 832 | File Cabinet | http://mxp.physics.umn.edu/s08/Projects/S08_SecondSoundHe | ||||
| 2007-05-04 00:00:00 | Cosmic Ray Experiments | Measuring the Angular Distribution of Cosmic Ray Muons | Cosmic ray muons often penetrate to the Earth?s surface and form a part of the background radiation that everything on the surface receives every day, thus it is important to understand the nature of this radiation. The general rule of thumb for cosmic ray muon angular distribution at the Earth?s surface is a cos2 dependence. We have taken data on muon flux at various angles relative to the zenith and found that although the general trend is similar to cos2 , the angular distribution of muons, at least locally, is more complicated, and may in face have a higher exponent. | Karn, Peter Kearsley, C.D. | Karn, Peter | Kearsley, C.D. | 710 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_CosmicRaysDistribution/ | ||||
| 2007-05-04 00:00:00 | Cosmic Ray Experiments | Measurement of the Energy Distribution of Particle Showers | We set out to measure the energy distribution of cosmic-ray particle showers using scintillator detectors to determine the flux of cosmic ray muons which are able to penetrate a known quantity of absorption material. We were able to investigate the background flux and plot a probability distribution for particles impinging our detector and determined that our detector is probably detecting particles other than muons. We were also able to measure the background flux for cosmic ray muons in Minneapolis, MN at a height of 840 meters to be 251±2 Counts/day. The accepted value is 213 Counts/day at sea level. | Hinrichs, Paul Lee, David | Hinrichs, Paul | Lee, David | 711 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_EDistributionParticleShowers/ | ||||
| 2007-05-04 00:00:00 | Particle Experiments | Changes in TLD Measurements as a Result of Neutron Radiation Exposure | We investigated the behavior of type TLD-100 lithium fluoride thermoluminescent dosimeters after they were exposed to neutron irradiation. We began by irradiating three TLDs with a neutron source for different lengths of time (1 day, 2days and 3 days). We then exposed the three neutron-irradiated TLDs and a calibration TLD to a cesium 137 source for different periods of time. Using a Harshaw 2500 TLD reader located at the hospital?s radiation oncology area, we correlated the amount of energy incident on the TLD with the amount of charge outputted by the TLD reader. This produced a linear calibration of what a non-neutron irradiated TLD should output in the TLD reader as a function of the energy incident on the TLD. With this, we could determine if the neutron-irradiated TLDS are accurately measuring the amount of energy incident on the TLD. In the end, we discovered that the neutron-irradiated TLDs were overestimating the incident energy. | Moses, Charlie Szczepanik, Cory | Moses, Charlie | Szczepanik, Cory | 720 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_TLD1/ | ||||
| 2007-05-04 00:00:00 | Particle Experiments | Particle Detection with Silicon Photomultipliers | Silicon photomultipliers (SiPMs) are a relatively new technology in scintillation detection, offering a number of practical advantages over standard photomultiplier tubes (PMTs) and avalanche photodiodes (APDs). In this article we will discuss some of the important difference between SiPMs and PMTs along with motivation for this investigation, outline the basics of the electronic implementation of SiPMs, and attempt to compare SiPM performance to that of PMTs. In addition to comparing the performance of the devices, we will discuss the construction of SiPM based detectors, especially for use in observation of cosmic showers. | Kersten, Kris West, Chris | Kersten, Kris | West, Chris | 721 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_CosmicShowerDecoherence/ | ||||
| 2007-05-04 00:00:00 | Condensed Matter Physics | Low Temperature Hysteresis and First Order Reversal Curve Diagrams of Single Domain Magnetite | We report new low temperature (<120K) dipole-dipole behavior of oxidized single domain magnetite (Fe3O4) by means of demonstrating the existence of twin peaks in FORC (first order reversal curve) diagrams. Hysteresis measurements were made when cooling the magnetite from 300K to 10K with different combinations of a 1.0 Tesla applied magnetic field and zero applied magnetic field. Our observed twin peaks represent interactions between magnetic dipoles of the magnetite grain and dipoles of its outer oxidized layer; this contradicts previous research claiming twin peaks are resultant of crystal twinning in the magnetite. These results are important for interpretations of low temperature magnetic measurements and provide new insight into the fundamental magnetic properties of magnetite at low temperatures. | Brown, Genevra Peterson, Benjamin | Brown, Genevra | Peterson, Benjamin | 730 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_Magnetite/ | ||||
| 2007-05-04 00:00:00 | Condensed Matter Physics | Electrical Spin Detection in Ferromagnet / Semiconductor Heterostructures | Understanding the physics of electrical spin detection in semiconductors is a problem central to the field of semiconductor spintronics. Here we investigate the spin detection properties if an Fe electrode on GaAs and demonstrate that the spin detection efficiency of an Fe electrode peaks for a Fe/GaAs interface voltage of 0.02 V. Our data also shows a change in the sign of the detected spin population for Fe detection electrodes under forward bias. This result provides information on the physics of electrical spin detection that is necessary to interpret measurements of two-terminal spin transport devices. | Toyli, David | Toyli, David | 731 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_ESpinTransport/ | |||||
| 2007-05-04 00:00:00 | Condensed Matter Physics | Synthesizing a Single Layer of Hetero-epitaxial Grapheme and Raman Spectrum at Different Layers of Graphene | Graphene is a single layer of carbon atoms densely packed into a benzene-ring structure. One of the major difficulties in the study of grapheme is to grow a pure and perfect single layer of grapheme. In this project, I propose a new method of synthesizing a hetero-epitaxial grapheme using a molecular beam epitaxy (MBE). I also present that graphite?s electronic structure is captured in its Raman spectrum that clearly evolves with the number of layers. The D? peak in Raman spectrum changes in shape, width, and position for an increasing thickness. This allows unambiguous and nondestructive identification of grapheme layers or thickness, which is lacking in this research area. | Lee, Yeonbae | Lee, Yeonbae | 732 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_Graphene/ | |||||
| 2007-05-04 00:00:00 | Condensed Matter Physics | Electrical Resistivity of Single Crystal Iron Whiskers as a Function of Temperature | The temperature dependence of single crystal iron whiskers has been measured from 4.2-290 K in the absence of applied magnetic field. Temperatures were obtained by raising sample above the level of the liquid in a helium storage dewar. Measurements of several whiskers are presented with comparison to earlier results and suggestions for further measurements. Sources of error include limited resistance resolution, approximately 1K deviations in temperature, and measurement of physical dimensions. This work represents the initial steps in the larger goal of comparing temperature dependence of resistivity and FMR measurements of iron whiskers. The apparatus has also been used to measure the superconducting transition of Niobium thin films, providing insight to the experimental precision. | Ouellette, Dan | Ouellette, Dan | 733 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_ResistivityofIron/ | |||||
| 2007-05-04 00:00:00 | Condensed Matter Physics | Measurement of Exchange bias of Co/CoO Bilayers | We originally proposed to measure the exchange bias of Cobalt/Coblat Oxide bilayers as a function of the crystal direction of the Cobalt Oxide layer. We used anisotropic properties of the sample at liquid helium temperatures (~4.5 Kelvin) to calculate the exchange bias by measuring the anisotropic magneto-resistance (AMR) and the planar Hall Effect voltage of the samples. We hoped to observe an effect dependent on the angle of the sample to the exchange-bias field. The effect yielded a linear result, and the remainder of the project consisted of attempting to discover what caused this discrepancy from earlier results. | Brinkman, Daniel | Brinkman, Daniel | 734 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_ExchangeBias/ | |||||
| 2007-05-04 00:00:00 | Condensed Matter Physics | Depolarized Reflected Light Microscopy of Bent-Core Liquid Crystal Films | We used a depolarized reflected light microscopy technique to search for biaxial properties in the liquid crystal compound UD180 in two different smectic phases. These results were then used to determine the orientation order of the mesogens in the liquid crystal. The film of UD180 displayed a 4 brush structure defect in the biaxial SmA phase. This is and indicator of biaxial properties with only full 360º symmetry. This implies the mesogens in the biaxial SmA phase of UD 180 are all orientated in the same direction from layer to layer. In the SmCP phase we encountered difficulties and were unable to draw useful conclusions on either its biaxial properties or orientation order | Johnson, Kyle Pastika, Joe | Johnson, Kyle | Pastika, Joe | 735 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_LiquidXTal/ | ||||
| 2007-05-04 00:00:00 | Atomic Physics | NMR Relaxometry of Ethanol | We examined pulsed nuclear magnetic resonance measurement techniques involving free precession. Techniques in measuring the characteristic longitudinal spin-lattice relaxation time ? T1, and the transverse spin-spin relaxation time ? T2, developed by Hahn, Carr and Purcell, and Meiboom and Gill in particular were used to observe the effect of concentration on the relaxation of ethanol C2H5OH. Radio frequency signals produced magnetic pulses to manipulate the net magnetic moment to observe its relaxation in the presence of a DC magnetic field. Variances in temperature and other systematic error prevented us from being able to determine a quantitative relationship between relaxation time and concentration, but we did qualitatively observe a non-linear decrease in relaxation time as the concentration of ethanol increases. | Ringham, Andrew Siorek, Margo | Ringham, Andrew | Siorek, Margo | 740 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_NMR/ | ||||
| 2007-05-04 00:00:00 | Optics | Measuring the Speed of Light | The speed of light was determined by modulating a monochromatic laser at a high frequency, on the order of 2 MHz, and measuring the change in the beam?s phase with respect to the change in the distance the light traveled. Typical measurements of the speed of light ranged from (3.04±0.01)x108 to (4.3±0.1)x108 m/s. The inaccuracies of the final results can most likely be attributed to the sensitivity of the apparatus to lateral displacements in the vertical and horizontal directions. By conducting an in-depth analysis of the phase to lateral displacement relationship, it was discovered that a beam drift of approximately o.4 mm could account for the inaccuracies in the final values. | Frederickson, Erin Rahmlow, Galen | Frederickson, Erin | Rahmlow, Galen | 750 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_SpeedofLight/ | ||||
| 2007-05-04 00:00:00 | Optics | Transmittance Through a Patterned Rexolite Disk | We desired to measure the transmittance of a 110 GHz radio source through a patterned Rexolite disk at various angles of incidence. The reflection-reducting pattern on our disk is the same as that which will be used on the field lens for the balloon-borne experiment EBEX, which aims to measure the polarized component of the Cosmic Microwave Background radiation. This experiment is a continuation of one performed last year, and as such our main goal was to reduce the standing wave phenomenon found previously. Theory gives the transmittance of a non-patterned and pattered Rexolite disk as 80% and 97%, respectively. We measure the transmittance of a non-patterned and patterned Rexolite disk as 83.5±0.9% and 96±2%, respectively. | Giesecke, Timothy McGranahan, Kathryn | Giesecke, Timothy | McGranahan, Kathryn | 751 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_Rexolite/ | ||||
| 2007-05-04 00:00:00 | Optics | Analysis of the Bending of an Aluminum Alloy Beam Under Stress Using Double Exposure Holographic Interferometry | Using a double exposure method of holographic interferometry we were able to determine Young?s Modulus of an aluminum alloy beam to be 45.9±0.2 Gigapascals. This is smaller than Young?s Modulus for any aluminum alloy beam we could find, but still allowed us to find the mass of two unknown weights within a standard deviation, two weights within four standard deviations and one weight within six standard deviations | Carlson, Raphael Klutzke, Kevin | Carlson, Raphael | Klutzke, Kevin | 752 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_HolographicBeamBending/ | ||||
| 2007-05-04 00:00:00 | Optics | Photon Counting Statistics | The goal of this experiment was to investigate the transition from Bose-Einstein to Poisson statistics for photon count distributions from a pseudo-thermal light source, produced by scattering laser light through a rotating round, glass plate. A relation between the reduced chi-squared from a fit to each of the distributions and the sampling time was to be found and discussed. However, many complications arose during this experiment, and the proposed result was not obtained. The most significant complications arose from the maximum counting frequency of the data acquisition card, which was measured to be much less than the model?s data sheet stated. This maximum counting frequency placed a limit on the intensity of the light to be measured and adversely affected the observed distributions in the cases where the intensity of the incoming light corresponded to a counting frequency higher than the DAQ could accurately measure. | Maxfield, Travis | Maxfield, Travis | 753 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_PhotonCountingStatistics/ | |||||
| 2007-05-04 00:00:00 | Acoustic | Acoustic Spatial Self-Focusing through a Random Medium using Iterative Time Reversal | Time symmetry in the acoustic wave equation can be exploited to produce pressure field focusing on a reflective object. An acoustic time reversal mirror (TRM) consisting of four elements was constructed to observe pressure focusing through a random scattering array. Varying the reflectivity ratio of two targets opposite the TRM allowed us to investigate its focusing capability defined by the relative pressure maxima as a function of spatial coordinates. For slightly different reflectivities, the ratio of the pressure maxima measured by the reflectors was found to decay geometrically with each successive time reversal iteration agreeing with the theory presented by Prada, et al. Asymptotic limits were observed in the maximum amplitude ratio for all reflectivity ratios investigated. These limits prevented the observation of geometric focusing for large reflectivity ratios. Some spatial limitations to focusing are discussed. | Donarski, Matt Fuller, Franklin | Donarski, Matt | Fuller, Franklin | 770 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_TimeReversedAcoustic/ | ||||
| 2007-05-04 00:00:00 | Nonlinear Systems | Inverted Pendulum Control | We have executed a control routine for maintaining a simple pendulum in the unstable equilibrium position. The proportional-integral-derivative (PID) method was implemented in LabWindows. The algorithm was interfaced with a stepper motor whose shaft was attached to an arm pinned to a pendulum. Once optimal parameters for the algorithm were established, trials were conducted in which individual gain constants were varied while controlling the others to observe changes in system behavior. Results obtained are consistent with models of driven harmonic motion. | McLaoughlin, Patrick Wolter, Christopher | McLaoughlin, Patrick | Wolter, Christopher | 780 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_Pendulum/ | ||||
| 2007-05-04 00:00:00 | Nonlinear Systems | Evaluation of a Complex System Using a Neural Network | We report on a method of evaluating the complexity of a given system through the architecture of the neural network capable of generalizing the system. A four channel EMG system recorded forearm action potentials for various hand positions, and a neural network was used to determine the complexity of each hand position. The complexity was defined by the minimum neural network capable of successfully generalizing the hand position. For the EMG system, it was determined that the minimum network capable of generalizing each hand position consisted of a different number of input units. It was also found that a distinction of activation characterizes the input units that are essential in generalizing the system. | Ketz, Nick Nord, Ashley | Ketz, Nick | Nord, Ashley | 781 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_NeuralNetWorks/ | ||||
| 2007-05-04 00:00:00 | Nonlinear Systems | Pattern Formation in Driven Magnetorheological Fluid Systems | A sample of ferrofluid in a dish is placed in a magnetic field, normal to the dish, which oscillates with a known frequency, amplitude, and offset. This magnetic field drives oscillations on the ferrofluid surface. Measurements of the surface waves have been made photographically. From this data we have determined the phases of the surface waves, and mapped the dependence of these phases on the frequency and the strength of the oscillations of the magnetic field. We have observed a linear relationship between the wave number and driving frequency reported by Hee-kyong Ko, Jysoo Lee, and Kyong J. Lee. | Broberg, Paul Erickstad, Michael | Broberg, Paul | Erickstad, Michael | 782 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_MRF/ | ||||
| 2007-05-04 00:00:00 | Misc | Mapping and Modeling of a Superconducting Levitation Magnet | We measured and mapped the magnetic field of a superconducting magnet. The particular magnet mapped possesses a high field gradient that allows its use for levitating diamagnetic materials. The strength and gradient of the field was mapped. The zone where levitation can occur inside the field was predicted and then found experimentally. This mapping will allow for future experiments to be conducted with this magnet, likely in the areas of magnetic resonance imaging (MRI), nuclear magnetic resonance (NMR) spectroscopy, and stray-field imaging. Dr. Bruce Hammer of the University of Minnesota?s Department of Radiology served as the advisor for this project. | Stein, Samuel | Stein, Samuel | 790 | File Cabinet | http://mxp.physics.umn.edu/s07/Projects/S07_BFieldMapping/ | |||||
| 2006-05-05 00:00:00 | Acoustic | Acoustophoresis as Method of Separation | An attempt was made to separate a mixture of water and latex polystyrene spheres using a water filled chamber driven to resonance with transducers. | Johnson, Daniel Steilen, Daniel | Johnson, Daniel | Steilen, Daniel | 670 | Resonance chamber, HV amplifier | File Cabinet | http://mxp.physics.umn.edu/s06projects/s06_acoustophoresis/ | |||
| 2006-05-05 00:00:00 | Misc | Crack Propagation Velocities in Plexiglas | The maximum cracking velocity of Plexiglas was measured by observing the change in resistance during cracking. It was found to be 830 +/- 170 m/s which is one standard deviation away from the previously published value of 960 m/s. | Abdullah, Mohamad Ambrose, Dan | Abdullah, Mohamad | Ambrose, Dan | 690 | Cracking Device, NI Scope Program, 20 MHz DAQ | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_Break/ | |||
| 2006-05-05 00:00:00 | Condensed Matter Physics | Corrections to Drude Conductivity Due to Weak Localization | We performed an experiment showing weak localization effects in a thin silver film. This quantum mechanical effect manifests itself as a correction to the Drude model of conductivity derived from classical mechanics. By measuring changes in resistance over a temperature range of 4.5 to 20 K and a magnetic field range of -2 to 2 T, we were able to observe results where spin-orbit dephasing dominated the process and caused positive magnetoresistance. | Bongaarts, John Ehrlichman, Michael | Bongaarts, John | Ehrlichman, Michael | 630 | PPMS | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_Drude/ | |||
| 2006-05-05 00:00:00 | Particle Experiments | Observations of In-Flight Positron Annihilations | We proposed to test the relativistic to semi-classical mass difference of positrons by measuring the in-flight annihilation energy of positrons produced by the ß-decay of Na22 into Ne22 with electrons. To do this we used two NaI scintillation detectors connected to a computer by an ADC. By doing so we hoped see a definite discrepancy between the semi-classical method and the relativistic method and thus demonstrate the more correct nature of the latter. Unfortunately, we were unable to determine this due to the low energy level and decay rate of our Na22 source and the sensitivity of our apparatus. | Gressman, Michele Pogemiller, Jim | Gressman, Michele | Pogemiller, Jim | 620 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_epem/ | ||||
| 2006-05-05 00:00:00 | Optics | Measurement of Verdet?s Constant for Water and TGG by the Faraday Effect | For this project used an acousto-optic cell in a heterodyne interferometer to measure Verdet?s constant for both water and a Terbium-Gallium-Garnet crystal. For TGG we determined Verdet's constant to be .50±.02 min/G-cm which is less than one standard deviation from accepted results. The poor results obtained from our water cell showed that this set-up is not a very accurate way to measure Faraday rotation. | Trandem, Kienan Stewart, Andrew | Trandem, Kienan | Stewart, Andrew | 650 | Solenoid Coil | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_Faraday/ | |||
| 2006-05-05 00:00:00 | Nonlinear Systems | Agitated Granular Media | We map the transition of a horizontally vibrated granular media from hexagonally packed to non-packed regimes by varying the areal density of the media. We quantitatively describe this transition using the method laid down by G.Strassburger and I.Rehberg[1], which is characterized by an order parameter determined from the pair distribution function of the media. The media, chrome-steel balls, were imaged using a Cannon Power Shot G3 camera, and the images were used to calculate the pair distribution function. When the media is driven sinusoidally at an amplitude of 1.0cm and frequency of 4Hz, a sudden transition in the behavior of the media was found for a filling fraction (effective two-dimensional density) of 10% to 50%. | Barnes, Elizabeth Beisang, Daniel | Barnes, Elizabeth | Beisang, Daniel | 680 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_Granular/ | ||||
| 2006-05-05 00:00:00 | Condensed Matter Physics | Measurement of the Quantum Hall Effect | This project involves measuring the quantum Hall Effect. By measuring the Hall voltage at low temperatures quantized levels have been observed and from these levels very accurate measurements of h/e2 have been obtained and have been measured. The accepted value of h/e2 is 25812.88Ù. The measured closest of the measured values is 25819.5±20 Ù, which is .03% and .4 sigma off. | Vassiliev, Kiril | Vassiliev, Kiril | 631 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_HallEffect/ | |||||
| 2006-05-05 00:00:00 | Optics | Double Exposure Holographic Interferometry | Through holography, vertical deflections of an aluminum bar were measured. A hologram of a metal beam was made when it was level and when it was bent from an applied weight. The hologram showed an interference pattern due to the different path lengths of light from each setup. The interference pattern did provided information about the bending of the beam. The measured experimental bending of the beam was compared to known theoretical equations for bending. | Campbell, Ian Wetterlund, Marc | Campbell, Ian | Wetterlund, Marc | 651 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_Hologram/ | ||||
| 2006-05-05 00:00:00 | Optics | Measurement of the Transmittance of a Patterned Rexolite Disk | We tested the theory of patterning a trapezoidal grid onto the surface of a disk in order to approximate an index gradient layering. We measured the transmission through both a patterned and a non-patterned Rexolite disk with a 110 GHz signal incident upon its surface. We expected the transmission through the non-patterned disk to be 80% and the transmission through the patterned disk to be 97%. We measured the transmission through the non-patterned disk to be 84 ± 7% and the transmission through the patterned disk to be 100 ± 2%. | Raach, Kate Schafer, Gina | Raach, Kate | Schafer, Gina | 652 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_Lens/ | ||||
| 2006-05-05 00:00:00 | Condensed Matter Physics | Measurement of Liquid Crystal Film Tension | Using a relation between the film tension and the radius for a spherical film, a new apparatus was used to measure the film tension of a liquid crystal film of H(8)F(4,2,1)MOPP at 60 C. The new system obtained a result of 27.0 +/- 0.3 dyne/cm which achieves higher precision but differs by 4.7 standard deviations from published values of 25.6 +/- 0.8 dyne/cm. | LaGrave, Tyler Voshell, Nick | LaGrave, Tyler | Voshell, Nick | 632 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_LiquidXtal/ | ||||
| 2006-05-05 00:00:00 | Condensed Matter Physics | Nuclear Magnetic Resonance | In our experiments, we investigated how the spin-lattice relaxation time, T1, and the spin-spin relaxation, T2, changed for various concentrations of water (H2O) in glycerin (C3H5(OH)3) and water mixtures. We obtained these measurements by primarily using a 15MHz pulsed nuclear magnetic resonance spectrometer. | Dos Santos, Troy Pearson, Daniel | Dos Santos, Troy | Pearson, Daniel | 633 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_NMR/ | ||||
| 2006-05-05 00:00:00 | Cosmic Ray Experiments | Measurement of The Energy Distribution of Particle Showers | We measured the energy distribution of particle showers using scintillation counters to record when a high energy particle passed through aluminum of various thicknesses. | Hamann, Michael Weaver, Timothy | Hamann, Michael | Weaver, Timothy | 610 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_ParticleShowerEnergy/ | ||||
| 2006-05-05 00:00:00 | Cosmic Ray Experiments | Measuring the Lateral Width of Cosmic-Ray Particle Showers | In this experiment we measured the lateral distribution of particle showers via the use of scintillation detectors. We measured the coincidence counts between multiple detectors and compared this to the lateral distance between the detectors. Our results, in particular the shape of our decoherence curves, are comparable to those seen by other groups who have performed this experiment and can be described by the Moliere-Bethe function. of cosmic-ray particle showers. | Beebe, Gretchen Peters, Ryan | Beebe, Gretchen | Peters, Ryan | 611 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_ParticleShowerSize/ | ||||
| 2006-05-05 00:00:00 | Optics | Photon Counting Statistics | We propose to resolve the differences in the statistics of photon counting. The differences divulge themselves as we examine two extreme cases. In one case, we expect our results to resemble a Poisson distribution. In the other: a Bose-Einstein distribution. | Berliner, Dan Moody, Brian | Berliner, Dan | Moody, Brian | 653 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_Photon/ | ||||
| 2006-05-05 00:00:00 | Acoustic | Sonoluminescence | This project produced stable and repeatable single bubble sonoluminescence with the intention of measuring the average size, emission spectrum, and emission intensity of the luminescent bubble in a fluid mixture of mostly water. The working procedure for producing sonoluminescence was carefully documented for future use. | Conneran, Renae Halberg, Justin | Conneran, Renae | Halberg, Justin | 671 | New Sonoluminescence Setup Flasks | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_Sonoluminescence/ | |||
| 2006-05-05 00:00:00 | Condensed Matter Physics | Suppression of Superconductivity in Nanowires by Bulk Superconductors | The resistance of a system of superconductive indium nanowires running perpendicular to two parallel lead bulk superconductors was measured with decreasing temperature. It was found that, below the critical temperatures of both indium and lead (3.4 K and 7.2 K respectively), the resistance of the system was non-zero. This experiment is based on that conducted by Moses Chan published in Physical Review Letters in August 2005. | Buchholz, Jessica Bruzzone, Daniel | Buchholz, Jessica | Bruzzone, Daniel | 634 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_Superconductivity/ | ||||
| 2006-05-05 00:00:00 | Cosmic Ray Experiments | Mass and Lifetime of Cosmic Shower Muons | We found the muon's life time to be 2.22 ± .02 µs which is within two error bars of the accepted value (1.97 µs). We found the energy to be 116 ± 13 MeV, within one error bar of the accepted value (105 MeV). | Hennen, Christopher Sirny, Dustin | Hennen, Christopher | Sirny, Dustin | 612 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_TauMuon/ | ||||
| 2006-05-05 00:00:00 | Acoustic | Time Reversed Acoustics | We measured the effects a few randomly positioned scattering centers have on the focusing power of Time Reversed Acoustics (TRA). We used a damped chamber with an array of ultrasonic detectors located on one end of the box to receive a signal from a single source, at the other end, that passes through various random configurations of scattering centers. What is received by the receivers is then reemitted in reverse and part of it follows the original trajectory back to the sender reconstructing the signal at that point. The dampening box minimizes noise and the sender and receivers are all in the same plane so analysis is simplified to analyzing the effect of our scatterers in two dimensions. | Quosig, David Shovelain, Justin | Quosig, David | Shovelain, Justin | 672 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_TimeReversed/ | ||||
| 2006-05-05 00:00:00 | Optics | Optical Tweezers | Focused laser light may be used to trap particles. Specifically, polystyrene spheres (n ~ 1.6), suspended in water (n ~1.3) will be attracted to, and trapped in, focused laser light, due to the forces generated as the laser light is refracted by the bead. By trapping 6 micron polystyrene spheres in the focused light of a HeNe laser and allowing water to flow through the flow cell containing the beads, the strength of the optical trap may be determined. | Karlstad, Rolf Peterson, Joseph | Karlstad, Rolf | Peterson, Joseph | 654 | File Cabinet | http://mxp.physics.umn.edu/s06/Projects/S06_Trap/ | ||||
| 2005-05-06 00:00:00 | Particle Experiments | Measurement of the Energy of Alpha Particles Using a Diffusion Cloud Chamber | Using a diffusion cloud chamber we measured the energy of the á particles emitted from an Americium-241 source and an unknown source. The energy obtained for Am-241 was (4.5 ± 0.1) MeV. The unknown source was determined to be most likely Po-210 with an observed energy of (5.6 ± 0.7) MeV. | Pemble, Brian Vasilakes, Nicholas | Pemble, Brian | Vasilakes, Nicholas | 520 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05Cloud/ | ||||
| 2005-05-06 00:00:00 | Condensed Matter Physics | Quantized Conductance in Gold and Silver Nanowires | Recent theory predicts and experiments have shown that the conductance across nanowires is quantized in units of G0=2e2/h=(12.9kÙ)-1. We reproduce these measurements by measuring the conductance of both gold and silver break-junctions. A piezoelectric bimorph was used to automate the tapping of two thin wires while a computer continuously monitored the conductance across the junction. A histogram of the frequency of different observed conductance values was created for both gold and silver, showing some evidence of quantization. The collected data did not yield itself to an accurate experimental measurement of G0. | Froehle, Brad Parker, Matt | Froehle, Brad | Parker, Matt | 530 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05Nanowires/ | ||||
| 2005-05-06 00:00:00 | Condensed Matter Physics | Resistance Measurements in Perpendicular Magnetic Fields of In2 O3 | The quantum correlation length and correlation time constants can demonstrate whether a transition is quantum mechanical or classical in nature. Either by measuring the thermopower or applying a perpendicular magnetic field to a sample of indium oxide one can see the sample exhibit a phase transition from a superconductor to an insulator that can be classified using the correlation length and time. In measuring the correlation length and time of a sample of indium oxide one can find out if a new form of matter, a Bose-insulator, is created. This experiment provides the process of determining the correlation length and time but came up with no definitive results. | Dally, Adam Hatke, Anthony | Dally, Adam | Hatke, Anthony | 531 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05Thermopower/ | ||||
| 2005-05-06 00:00:00 | Condensed Matter Physics | Measurement of the First, Second, and Fourth Sounds of Super fluid He II | In this experiment, sound velocity measurements were made in super fluid He II using the method of resonating chambers as a function of temperature, with the temperature ranging from 1.4 K to 2.3 K. Properties that can be derived from sound velocity data are the thermal-expansion coefficient, entropy, specific heat, isothermal compressibility, and the density of the fluid. | Cruse, Nick Stromme, Michelle | Cruse, Nick | Stromme, Michelle | 532 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05He/ | ||||
| 2005-05-06 00:00:00 | Condensed Matter Physics | Measurement of Electric Field in a Fe/GaAs Interface Via the Franz-Keldysh Effect and a Suspected Quantum Bound State Transition in Differential Reflectance | In this experiment, we have constructed an apparatus to take reflectance and photo reflectance spectrums of a metal-semiconductor sample. By use of the reflectivity and photo reflectivity data we measured quantities such as a band gap energies and in particular, observed the Franz-Keldysh effect. From the period of the Franz-Keldysh oscillations the electric field within the sample can be determined. We estimated that the electric field within our sample is not uniform. For comparison, another experiment that was done on a sample with a uniform electric field found a value of 50 kV/cm. | Pearson, Ben Shearer, Paul | Pearson, Ben | Shearer, Paul | 533 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05Franz/ | ||||
| 2005-05-06 00:00:00 | Atomic Physics | Pulsed NMR Analysis of the Changes in Spin-Lattice and Spin-Spin Relaxation Times for a Five-Minute Curing Epoxy | We have used the techniques of pulsed NMR to determine how the spin-lattice and spin-spin relaxation times of a ?five-minute epoxy? vary over time as the epoxy cures. The experiment was performed with a TeachSpin pulsed NMR. There appeared to be no appreciable variation in either spin-lattice or spin-spin relaxation times over the five-minute period for which the epoxy cured. | Madhavan, Arun Hanson, Abe | Madhavan, Arun | Hanson, Abe | 540 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05NMR/ | ||||
| 2005-05-06 00:00:00 | Optics | Measurement of Hyperfine Structure Using Rubidium Gas and Saturated Absorption Spectroscopy | The experiment involved the observation and measurement of the hyperfine-splitting transition frequencies of the valence electron states in rubidium (Rb). The measurement was carried out by means of saturated absorption spectroscopy, in order to filter out the rest-frame frequency in the absence of Doppler shifts, using a tunable diode laser. The main goal of this experiment was to seek out the transition frequencies to within a Äfpeak/fpeak resolution of almost one in forty million (in the most ideal case). However, we were unable to make the necessary measurements of the hyperfine spacings due to the instability in our diode-laser-external feedback set up. We did observe saturated absorption features, but due to insufficient resolution of the individual features, we could not produce the desired results. | Beverlin II, Bryce Emani, Prashant | Beverlin II, Bryce | Emani, Prashant | 541 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05Rb/ | See also 0352 | |||
| 2005-05-06 00:00:00 | Optics | Measurement of the Speed of Light Using an AO Cell | This experiment attempted to measure the speed of light by using an acousto-optical cell to modulate the intensity of a He-Ne Laser beam. The beam traveled a short, known, variable distance, which could accurately be measured, and the phase change of the wave was measured using a lock-in amplifier, at each distance. By using short distance changes that can be very accurately measured the value of the speed of light was expected to be measured precisely. The setup used did not yield consistent results, and the value for the speed of light was not able to be determined. | Pettingill, Sara | Pettingill, Sara | 550 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05SpeedOfLight/ | |||||
| 2005-05-06 00:00:00 | Optics | Measuring the Force of Optical Tweezers | Purpose is to measure the spring constant of a 3 dimensional potential well created by a laser that traps a one micron polystyrene sphere. Our apparatus uses an oil immersion objective and a CCD camera. The motion will be analyzed so that the strength of the trap may be calculated. | Hoglund, Richard Tuominen, Brenton | Hoglund, Richard | Tuominen, Brenton | 551 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05Tweezer/ | See also: 0452,0654 | |||
| 2005-05-06 00:00:00 | Optics | Measurements of Hydrodynamic Radii by Dynamic Light Scattering | Dynamic Light Scattering is a procedure by which scattered light, incident on particles undergoing Brownian motion in a solution, can be analyzed to determine the suspended particle?s approximate size. The particles in question are usually on the order of nanometers to microns in diameter. Our experiment yielded 507±54 nm for our 500 nm solution and 133±10.6 nm on average for our 240 nm solution. We also saw as our concentration increased with 500 nm spheres in solution from 2:1002 to 10:1010 the calculated size of the particles started at 143±11 nm and rose to 280±22 nm, respectively. We expected this to actually exponentially decrease from the actual value as the concentration decreased. | Gilman, Adam Lloyd, Aaron | Gilman, Adam | Lloyd, Aaron | 552 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/s05lightscattering/ | See also:0450, 0350 | |||
| 2005-05-06 00:00:00 | Optics | Photon Counting Statistics | A pseudo random light source was created by passing a HeNe laser beam through a rotating round glass disk. The number of photons in the scattered beam were measured and sorted using a histogram. The resulting distributions showed characteristics of Poisson distributions over sampling times ranging from 0.015 to 0.15 ms. Characteristics of Bose-Einstein distributions were sought for sampling times near 0.01 ms. | Sydow, Max | Sydow, Max | 553 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05Photon/ | See also: 0653, 0351, 0150 | ||||
| 2005-05-06 00:00:00 | Acoustic | The Observation and Production of Sonoluminescence | Sonoluminescence is a phenomenon wherein acoustic energy is transformed into light energy. A 50 micron sized gas bubble is sustained in water and put through oscillating compressions by an intense acoustic field. These compressions cause a brief photon emission from the bubble. The mechanism by which this energy transfer is made is not yet understood. | Obiadazie, Arthur Werner, Lewis | Obiadazie, Arthur | Werner, Lewis | 570 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05Sonoluminescence/ | ||||
| 2005-05-06 00:00:00 | Acoustic | Measurement and Prediction of Reverberation Times in a Concert Venue | The purpose of this project is to make accurate measurements of the reverberation times of sound waves in a music venue before and after the walls are treated with acoustic paneling. We want to predict and measure how the reverberation time in the venue changes with the change in boundary characteristics. Our measurements yielded a decrease in the reverberation on the order of ~100 msec, depending on the octave band, while we predicted a decrease in the reverberation time on the order of only ~10 mssec, depending on the octave band. | Goetzman, E.M Sclavi, Chad | Goetzman, E.M | Sclavi, Chad | 571 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05Reverb/index.htm | ||||
| 2005-05-06 00:00:00 | Nonlinear Systems | Control of a Pendulum in its Unstable Equilibrium Position | We maintained a pendulum in its unstable equilibrium position. The pendulum is restricted to rotate around only one axis. The pendulum is mounted on the end of a rotating arm such that the pendulum?s axis of rotation is parallel with the rotating arm. The angle of the pendulum with respect to vertical is measured with a potentiometer mounted in the pendulum?s pivot. This angle is recorded into a computer with a data acquisition card (DAQ). The computer then controls a motor driving the rotating arm by making the DAQ produce a pulse train that controls the motor speed such that the motion of the arm counteracts the pendulum falling. A successful completion of this experiment would be a step towards developing robots with the same agility as humans. | Childs, Alex Strommes, Jeremy | Childs, Alex | Strommes, Jeremy | 580 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05PID/ | See also: 0380 | |||
| 2005-05-06 00:00:00 | Misc | Variation in Passive Drag Due to Swimsuit Design | The passive drag of three different swimming suits was measured by towing a subject through water at a constant velocity. A Speedo practice suit, a Speedo Fastskin II racing suit, and a TYR Aqua Shift racing suit were the three different suits used. From the data collected by a load cell and electronics circuit, measuring the tension in the towrope, both of the suits reduce the amount of drag on our subject by about 5% each. This comes from the values of mpractice = 11.3 ± 0.3 kg, mSpeedo=10.8 ± 0.2 kg, and mTYR = 10.6 ± 0.2 kg, corresponding to the mass needed to keep the subject moving at a constant velocity. Or results are inconclusive as to which competitive racing suit is better at reducing drag. From the values stated the two competitive suits have too much overlap in the uncertainty to declare that one is better than the other. | Beckerle, Travis Mortimer, Justin | Beckerle, Travis | Mortimer, Justin | 590 | Load Cell | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05Swim/ | |||
| 2005-05-06 00:00:00 | Misc | Dynamics of a Spherical Foucault Pendulum | We measure the Foucault precession in a spherical pendulum due to the rotation of the Earth, and compare it with theoretical predictions. A pendulum of the size we constructed would be suitable for lecture demonstrations. We measure the position of the pendulum in time using two low-friction turn pot encoders. Due to stray torques in the apparatus, the observed precession of (0.3864 ± 0.0003) o per hour counterclockwise is more that an order of magnitude smaller than the expected 10o per hour clockwise. | Bryan, Sean Zilic, Kyle | Bryan, Sean | Zilic, Kyle | 591 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05SphericalPendulum/ | ||||
| 2005-05-06 00:00:00 | Misc | Volume Magnetostriction of a Soft Ferrite Core Embedded in a Particulate Medium and Subjected to High Compressive Stresses | An experiment was conducted to determine the stress sensing capabilities of a wound soft ferrite toroid embedded in a host media, specifically concrete and other structural composites. It was observed that under increasing pressure in a steel chamber piston combination filled with 3M Zeeospheres, a Manganese Zinc ferrite toroid will exhibit a uniform non-linear drop in inductance for pressures up to 50 megaPascals. This characteristic drop in inductance was repeatable and did not result in a destruction of the core. Various geometrical conditions were explored, as well as an epoxy filled core which when put under pressure linearized the inductance versus pressure curves. It is believed that there is a connection between negative inverse magnetosctriction of the core and its dropping inductance under pressure. Hysteresis loops were observed for inductance versus pressure measurements. In concrete, similar reproducible inductance versus pressure curves were observed. | Nutter, Mark Powers, Matt | Nutter, Mark | Powers, Matt | 592 | File Cabinet | http://mxp.physics.umn.edu/s05/Projects/S05Magnetostriction/ | ||||
| 2004-05-07 00:00:00 | Particle Experiments | Determination of Potassium-40 in Food by Measuring Radioactivity | Gamma rays from foods known to be high in potassium-40 were studied. The amount of potassium could be deduced from the 1.46 MeV gamma rays detected by a sodium iodine detector. | Malmin, Ryan | Malmin, Ryan | 420 | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04bkgrad/ | |||||
| 2004-05-07 00:00:00 | Condensed Matter Physics | Sound Velocity Measurements in He II | Using the method of resonator cells, we attempted to measure the velocities of the first, second and fourth sound in He II between 1.4 K and the lambda point. Results for second sound velocity as a function of temperature are given, while technical difficulties prevented the measurement of first and fourth sound. | Mecklenburg, Matthew Wicklund, Andrew | Mecklenburg, Matthew | Wicklund, Andrew | 430 | New 1st 4th sound cell | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04he/ | |||
| 2004-05-07 00:00:00 | Misc | Generating Cherenkov Radiation by Passing an Electron Beam over Titanium Dioxide | A system to generate microwave Cherenkov radiation by passing a thin, low-energy electron beam in close proximity over the surface of a titanium dioxide sheet was built and tested. A microwave diode was used to detect the radiation. Data collected and analyzed was inconclusive. | Manfred, Michael Sadjadi, Farzad | Manfred, Michael | Sadjadi, Farzad | 490 | Updated electron gun | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04cherenkov/ | |||
| 2004-05-07 00:00:00 | Optics | Dynamic Light Scattering | The hydrodynamic diameters for different sized latex spheres were measured using dynamic scattering of coherent light. | Ickler, Derek Raney, Jordan | Ickler, Derek | Raney, Jordan | 450 | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04light/ | ||||
| 2004-05-07 00:00:00 | Particle Experiments | Analysis of Pair Production in Iron | Electron ? Positron pairs were produced in a 3 cm radius iron cylinder. We detected the products of the annihilation of the positron (two equal gamma rays) with plastic scintillators attached to photo multiplier tubes. | Larson, Michael Wittrock, Jason | Larson, Michael | Wittrock, Jason | 421 | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04epem/ | ||||
| 2004-05-07 00:00:00 | Particle Experiments | Measurement of the Gamma Spectrum from Neutron Induced Fission in U238 | A measurement of the gamma spectrum from neutron-induced fission in U238 was made. A Plutonium-Beryllium source bombarded the U238 with neutrons at 1 MeV where the cross section is approximately one Barn. The background radiation from the PuBe was very high and consequently we were not able to detect the fission gammas. | Erickson, Jakob Peterson, Eliot | Erickson, Jakob | Peterson, Eliot | 422 | File Cabinet | |||||
| 2004-05-07 00:00:00 | Condensed Matter Physics | Characteristics of H2 Sorption onto Metal-Organic-Frameworks | The interaction energy between molecular hydrogen and the metal organic framework 5 crystal was measured. Also, the H2 loading of the MOF-5 crystal was measured at temperatures of 78 K and 298 K and pressures from 0.2 bar to 160 bar. Results show that in addition to the expected 1.2kcal/mol binding site there are additional sites near the corners of the MOF-5 crystal with binding energies up to 1.8 kcal/mol. | Klassen, James | Klassen, James | 431 | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04mofs/ | |||||
| 2004-05-07 00:00:00 | Misc | The Fin Effect on Temperature Readings Using a Thermocouple | The temperature difference due to the ?Fin Effect? between the ?actual? and the measured temperature for a plastic disc was measured. | Archambault, John | Archambault, John | 491 | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04heat/ | |||||
| 2004-05-07 00:00:00 | Nonlinear Systems | Probability of Jamming in a Two-Dimensional Hopper | The probability of jamming when uniform balls are placed in a two-dimensional hopper were studied as a function of the ratio of hopper throat width to ball diameter. Results were compared to computer simulations using a distinct element model. | Abuzzahab, Omar Lorig, Matthew | Abuzzahab, Omar | Lorig, Matthew | 480 | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04hopper/ | ||||
| 2004-05-07 00:00:00 | Condensed Matter Physics | Josephson Junction Tunneling | The experiment characterized the behavior of a Niobium ? Niobium Oxide - Niobium Josehpson Junction. Critical current and flux quantum were measured at liquid helium temperatures. | Braaten, Tyler Lonjers, Jeff | Braaten, Tyler | Lonjers, Jeff | 432 | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04josephson/ | ||||
| 2004-05-07 00:00:00 | Optics | Trapping Particles in a Coupled Hollow Fiber | The trapping of 100 nm ? 10 um particles in hollow core fiber has been shown to be possible. Our experiment was designed to duplicate these results and expand on the work done. Though we were able to find some promising results, we were not able to reproduce particle trapping. | Bierbaum, Andrew Sigrist, Nathaniel | Bierbaum, Andrew | Sigrist, Nathaniel | 452 | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04trap/ | ||||
| 2004-05-07 00:00:00 | Cosmic Ray Experiments | Magnetic Moment of Muon | In preparation for the physical measurement of the muon magnetic moment from the distribution of the positrons emitted from the u+ stopped in a B field, Monte Carlo simulations were used to demonstrate the feasibility of the proposed experimental setup. The actual experiment then showed that the precession signal could be discerned with as few as 10k events. The best values for g and the lifetime were found to be g = 2.4 +/- 0.2 and t = 2.2 +/- .5 usec. | Ma, Yousi | Ma, Yousi | 410 | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04muon/ | |||||
| 2004-05-07 00:00:00 | Atomic Physics | Pulsed NMR and the Viscosity Dependence of Spin-Lattice Relaxation in Glycerin and Water Mixtures | The spin-lattice relaxation time was determined as a function of water concentration in glycerin using a pulsed NMR technique. | Boyle, Katy Wesson, Gregory | Boyle, Katy | Wesson, Gregory | 440 | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04nmr/ | ||||
| 2004-05-07 00:00:00 | Misc | Noise Reduction in Radio Astronomy | The project built a noise-reduction system for a radio telescope. The interference present was analyzed and found to be variable in frequency and close enough to the hydrogen line that a filter would block important data. The signal received by a Yagi loop antenna was correlated with the signal received by the telescope to remove noise. | Busch, Michael | Busch, Michael | 492 | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04radast/ | |||||
| 2004-05-07 00:00:00 | Optics | Zeeman Effect Through Optical Rubidium Pumping | We examined the hyperfine structure and the Zeeman effect by using optical pumping of rubidium gas through the resonant absorption of light. | Harris, Katherine | Harris, Katherine | 441 | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04rbpump/ | |||||
| 2004-05-07 00:00:00 | Misc | Temperature Dependence of Ice-Crystal Structures | The experiment investigated the temperature dependence of ice-crystal structures. In the temperature range applied, five distinct crystal structures were observed: plates, columns, prisms, needles and dendrites. | Abrahamsen, Tavis Spencer, Justin | Abrahamsen, Tavis | Spencer, Justin | 493 | Diffusion Chamber | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04snow/ | |||
| 2004-05-07 00:00:00 | Condensed Matter Physics | X-Ray Fluorescence Spectroscopy | X-Ray Fluorescence Spectroscopy was used to determine the composition of unknown materials. | Buckman-Ellis, Joseph | Buckman-Ellis, Joseph | 433 | XRF | File Cabinet | http://mxp.physics.umn.edu/s04/Projects/s04xrf/ | ||||
| 2003-05-09 00:00:00 | Condensed Matter Physics | Measurement of the Velocities of Second Sound in Liquid He II | The purpose of this experiment was to describe and measure first, second and fourth sounds in liquid Helium II. We used two different apparatus arrangements and were successful in measuring second sound with both of them. Our results for second sound were consistent with themselves and a good representation of calculated values. We were unable to measure first and fourth sounds in the time allotted. | Hairrell, Jacob Trinh, Jeff | Hairrell, Jacob | Trinh, Jeff | 330 | New Cell | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03He/ | |||
| 2003-05-09 00:00:00 | Misc | Measuring the Gravitational Constant Using an Electronic Torsion Balance | This experiment attempted to measure the gravitational constant G. It used a torsional balance that is compensated by magnetic forces from Helmholtz coils acting on a magnetic dipole attached to the arm of the balance. The position of the rod remains fixed and any change in external torque results in a change in the current through the two Helmholtz coils. Calibration involves determining the current change per unit torque through a measurement of the damped period. In this manner the torque induced in the vicinity of two large iron masses can be measured. Our best value of G was 37 times larger than the accepted value. | Geppert, Chad Zisla, Lloyd | Geppert, Chad | Zisla, Lloyd | 390 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03G/ | ||||
| 2003-05-09 00:00:00 | Optics | Measurement of the Hydrodynamic Radius of Polymer Microspheres by Dynamic Light Scattering | Dynamic light scattering technique was used to measure the hydrodynamic radii of 240 and 500 nm polymer spheres. The experiment consists of He-Ne laser light incident on spheres suspended in water. A photo detector at a 90-degree angle to the incident light measures the intensities of the light scattered from these spheres as a function of time. The intensities are used to measure the diffusion coefficient and to calculate the hydrodynamic radii of the particles. The values obtained were within 5 % of those determined by NIST. | Kelley, Paul Temim, Tea | Kelley, Paul | Temim, Tea | 350 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03Light/ | ||||
| 2003-05-09 00:00:00 | Nonlinear Systems | Intelligent Control of the Inverted Pendulum | We describe the work on a system to balance a pendulum at its unstable equilibrium point. The system uses a stepper motor that controls a horizontal rotating arm with the pendulum attached to the end. A DAQ is used to measure the pendulum?s vertical position. This information is then used in a proportional-integral algorithm to control the stepper motor?s and the arm?s velocity and acceleration and, hence, to exert a torque on the pendulum to keep it, ideally, upright. The behavior of the system is described for the various control parameters and a simulation is discussed. | Egeland, Ricky Renna, Kevin | Egeland, Ricky | Renna, Kevin | 380 | Inverted Pendulum Apperatus | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03Pend/index.html | |||
| 2003-05-09 00:00:00 | Condensed Matter Physics | Josephson Junction | In this experiment we used the characteristics of a Niobium-Aluminum oxide-Niobium junction to determine the magnetic flux quantum. We also characterized the I-V curve, observing hysteresis and the energy gap of the superconductor niobium to be 2.81 +/- 0.01 meV. From the quantum phenomena of the Frauenhofer patterns we determined the flux quantum to be (1.97 +/- 0.34) x 10-15 Wb; using the junction characteristics of the Fiske steps we determined the flux quantum to be (2.30 +/-0.64) x 10-15 Wb. | Gray, Aaron Pham, John | Gray, Aaron | Pham, John | 331 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03Josephson/ | ||||
| 2003-05-09 00:00:00 | Misc | Measuring the Coupling between Two Coils Using a Microstructure Material as a Magnetic Flux Guide | Microstructures are materials that have a small size compared to the wavelength of the electromagnetic radiation of interest. We made a Swiss roll microstructure and we measured the gain as a function of distance between the two coils at the roll?s resonance frequency with and without the roll. | Sander, Aaron Swintek, Joe | Sander, Aaron | Swintek, Joe | 391 | Swiss Roll | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03LeftHand/ | |||
| 2003-05-09 00:00:00 | Condensed Matter Physics | Magneto-Optic Kerr Effect and Anisotropy of an Iron Cobalt Film | The nature of magnetic anisotropy in a thin film of FeCo on a flat GaAs substrate was investigated. Hysteresis loops along three orientations of the film were measured, namely along the easy, the intermediate and the hard axis. | Kleinjan, David Lemmerman, Jeffrey | Kleinjan, David | Lemmerman, Jeffrey | 332 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03Moke/ | ||||
| 2003-05-09 00:00:00 | Cosmic Ray Experiments | Determination of the Magnetic Moment of Cosmic Muons | This experiment was designed to measure the mean lifetime of muons incident from cosmic rays and to determine the Lande g-factor for the muons. A mean lifetime of 2.21 +/- 0.40 us was measured after 5 days of running. A magnetic field produced by a rectangular solenoid around the Al target was used to measure the precession of the muons to determine their magnetic moment; unfortunately, not enough data could be acquired in the time remaining. | Martell, Aaron Thibodeau, Matthew | Martell, Aaron | Thibodeau, Matthew | 310 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03Muon/ | ||||
| 2003-05-09 00:00:00 | Misc | Group Delays in a Circuit and an Optical System | A circuit capable of producing negative group delays was investigated. An optical experiment also measured laser pulse width and the dispersion and refractive index of glass. | Caven, David Steuck, Mathew | Caven, David | Steuck, Mathew | 392 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03NegV/ | ||||
| 2003-05-09 00:00:00 | Misc | Using a Feedforward Neural Network to Center the Emission of a Laser Diode on a Quartered Photodiode | An artificial Feedforward Neural Network (FNN) has been successfully trained to center the emission of a laser diode on a quartered photodiode. | Midwinter, Charles | Midwinter, Charles | 393 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03Neural/ | |||||
| 2003-05-09 00:00:00 | Cosmic Ray Experiments | Zeeman Resonances Observed Through Optical Pumping in Rubidium | Zeeman splitting in Rb 85 was measured and compared to the model given by the Breit Rabi equation. The data fit the model with a reduced chi square of 0.7. | Covault, Rachel | Covault, Rachel | 340 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03RbPump/ | |||||
| 2003-05-09 00:00:00 | Optics | Photon Statistics and Coherence of Light Sources | Two experiments were designed to explore light coherence, both spatially and temporally. The first makes use of a pseudothermal light source, which has an extremely long coherence time. By sampling this source above and below the coherence threshold, the experiment successfully showed that at times longer than the coherence time, photons must be described with Poisson statistics; at times shorter than the coherence time, photons must be described with Bose-Einstein statistics. The second experiment used a Michelson interferometer to measure the coherence length of three lasers. | Boyer, Martha Ortlip, Erik | Boyer, Martha | Ortlip, Erik | 351 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03PhotStat/ | ||||
| 2003-05-09 00:00:00 | Optics | Saturated Absorption Spectroscopy of Rubidium | The hyperfine structure of the 5P3/2 state of Rb was measured through saturated absorption spectroscopy. The results were in statistical agreement with recent measurements made using a more accurate technique. | Kleckner, Dustin | Kleckner, Dustin | 352 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03RbSat/ | |||||
| 2003-05-09 00:00:00 | Optics | Schlieren Photography | Schlieren Photography is used to visualize the gradients of the indices of refraction in transparent media. Two systems were investigated: the off-axis single mirror system and the z-type two-mirror system. A calibration was done such that the intensity of the image could be related to a value for the gradient of the refractive index. This information was used to analyze an image of a stream of alcohol vapor in air and the image of the boundary between water and alcohol. | Bauer, Bonnie Krake, Vanessa | Bauer, Bonnie | Krake, Vanessa | 353 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03Schlieren/ | ||||
| 2003-05-09 00:00:00 | Atomic Physics | Emission Spectrum from Microwave Stimulated Plasma | The emission spectrum of a microwave-stimulated plasma was analyzed. Containment and stabilization of the plasma using a magnetic bottle and surrounding electric fields was also investigated and an attempt to sustain the plasma using only magnetic and electric fields with microwave source turned off was also tried. | Kauer, Matthew | Kauer, Matthew | 341 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03Microwave/ | |||||
| 2003-05-09 00:00:00 | Optics | Optical Heater for Liquid Helium | An optical heater was constructed; it will be used to create pulses of helium atoms projected towards a superfluid film. The laser has been assembled and we found a that 1320 nm thick film of lead, or a combination of zinc and silver, most effective in converting the energy from light into heat. | Dunsmore, Joseph Jay-Dixon, Daniel | Dunsmore, Joseph | Jay-Dixon, Daniel | 354 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03ThermalHe/ | ||||
| 2003-05-09 00:00:00 | Condensed Matter Physics | Vibrating Sample Magnetometry | Using Vibrating Sample Magnetometry (VSM) we were able to measure the saturation magnetic moments of Nickel and Gadolinium at 77 K. Furthermore, we measured the saturation magnetization for Ni and Gd at 77 K and 298 K and the magnetic susceptibility for Gd at room temperature. In addition we measured the magnetic coercivities for Ni and Gd at room temperature and at 77 K. | Chen, Benjamin Scott, Deborah | Chen, Benjamin | Scott, Deborah | 334 | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03OVSM/ | ||||
| 2003-05-09 00:00:00 | Condensed Matter Physics | Magnetic Susceptibility Measurements Using a Tunnel Diode Oscillator | A Tunnel Diode Oscillator circuit was built for use in magnetic susceptibility measurements of Bismuth at room temperature and the change in susceptibility of CrO8S2 12H2O. The apparatus was successfully used to measure the transition temperature of Niobium and to observe the change in its skin depth. | Seeley, Anthony Staley, Neal | Seeley, Anthony | Staley, Neal | 333 | Tunnel Diode Oscillator Circuit RF Amplifier Board | File Cabinet | http://mxp.physics.umn.edu/s03/Projects/S03Osc/ | |||
| 2002-05-17 00:00:00 | Condensed Matter Physics | Measuring the Magnetic Moment of a Ferromagnetic Sample Using an AC Torque Magnetometer | The goal of our project is to use a torsion oscillator magnetometer and a uniform magnetic field to measure the effective magnetic dipole moment of crystals in an anisotropic thin film. We will be using an AC torque magnetometer that measures the frequency of oscillation about the dipole moments? equilibrium orientation. By measuring the changes in this frequency due to applied magnetic fields, we can infer the effective dipole moment of crystals in the film. | McBrady, Collin Zens, Tim | McBrady, Collin | Zens, Tim | 230 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/Torque/summary.htm | ||||
| 2002-05-17 00:00:00 | Nonlinear Systems | Brazil-Nut Effect in a Vacuum | The Brazil-nut effect describes the segregation effect of larger particles in a mixture rising to the op when shaken. This phenomenon is characteristic of all granular media. Recent studies have shown that along with the physical interaction of the beads the interstitial air might be involved in this process. Our research examines how reduced air pressures down to about 0.42 Torr influence this effect. We found that there is no such correlation between air pressure and the rise time in the Brazil-nut effect. | Hoekman, John Ziegler, Brian | Hoekman, John | Ziegler, Brian | 280 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/Brazil/ | ||||
| 2002-05-17 00:00:00 | Optics | Tunable Diode Laser for Photoluminescence Spectroscopy and Optical Pumping of Spin States | The experiment sought to determine if an open cavity tunable diode laser (OCTDL) using a diffraction grating is a useful and practical tool for the study of photoluminescence excitation spectroscopy (PLE) and for the optical pumping of spin states in a quantum well. For this experiment a p-doped GaAs / AlGaAs sample with Al and Ga concentration of 30% and 70% respectively were used. This sample contained 10 quantum wells, each with a width of 150A. While the OCTDL performed well for the optical pumping of spin states and yielded the expected results, its limited range of tunability made it impractical for PLE, as it was unable to reach the wavelengths of light corresponding to transitions in the quantum well. | Borgert, Andrew | Borgert, Andrew | 250 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/QWells/ | |||||
| 2002-05-17 00:00:00 | Optics | Magnetic Characterization of Thin Fe-Co Films Utilizing the Magneto-Optical Kerr Effect | We constructed an apparatus to perform magnetic characterization of reflective thin films. Differential reflectivity measurements were applied to measure the transverse Kerr effect and a method of crossing polarizers was used to measure the longitudinal Kerr effect and we were able to identify the two in-plane components of the magnetization. These techniques were then applied to characterize some of the magnetic properties of two thin Fe-Co films. All data taken matched the predictions reasonably well. | Leland, Jeanette Tomatz, Michael | Leland, Jeanette | Tomatz, Michael | 251 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/MOKE/ | ||||
| 2002-05-17 00:00:00 | Particle Experiments | Positron ? Electron Pair Creation and Annihilation | In this experiment we sought confirmation of the production of the electron and its antiparticle, the positron, by observing the gamma rays characteristic of the particles? annihilation. While we were not able to obtain accurate quantitative data, our results confirm the presence of annihilation gamma rays. | Corwin, Luke | Corwin, Luke | 222 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/EECreation/default.htm | |||||
| 2002-05-17 00:00:00 | Particle Experiments | Gamma Ray Spectroscopy | A gamma ray spectrometer with a veto shield was built. After plateauing the phototubes, the spectrum of Na 22, Co 60, Ba 133 and Cs 137 was measured using a QVt. The results were then compared with existing data. | Lee, Derek Vetter, Yon | Lee, Derek | Vetter, Yon | 221 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/Fission/default.htm | ||||
| 2002-05-17 00:00:00 | Particle Experiments | Measurement of the Lifetime of Cosmic Ray Muons as a Function of Atomic Number | The intention of this project is to measure the lifetime of muons that have been captured by an atomic nucleus and to compare this to the lifetime of free muons. A wooden box with alternating layers of plastic scintillators and test materials (Al & Pb) were used and compared with data where no test material was used. We were unable to measure nuclear capture rates but we measured the free muon lifetime. | Austin, Crystal Mayer, Nathan | Austin, Crystal | Mayer, Nathan | 220 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/MuonLifeTime/default.htm | ||||
| 2002-05-17 00:00:00 | BioPhysics | New Model for Localized Warming to Suppress Shiver in Mildly Hypothermic Patients | In our experiment, we developed new coverlets designs to locally warm the body with air. Local warming reduces shivering in a cold environment. This allows doctors to induce mild hypothermia without the use of pharmaceuticals. The induction of mild hypothermia is important in preventing brain damage in head trauma patients. We confirmed that mild hypothermia was achieved and on the basis of temperature, heat flux and blood flow measurements determined the most effective coverlet design for applying warm air to the hands. | Johnson, Lisa Schweiker, Katrina | Johnson, Lisa | Schweiker, Katrina | 260 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/Shivering/default.htm | ||||
| 2002-05-17 00:00:00 | BioPhysics | Surface Electromyography and Muscle Fatigue | The objective of this experiment was to confirm that the frequency spectrum of an electromyography (EMG) signal shifts to lower frequencies as a muscle, under voluntary contraction, fatigues. The primary motivation for the experiment, however, was to gain engineering experience through the design and construction of the actual apparatus used to measure the EMG signal. Over the course of a two-minute experiment recording the mean EMG frequency from my right bicep, I observed the predicted downward shift in frequency as fatigue occurred. | Beltt, Eric | Beltt, Eric | 261 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/Muscle/default.htm | |||||
| 2002-05-17 00:00:00 | Acoustic | Chladni Plate Modes Using a Drumhead | The conventional method of demonstrating Chladni modes of a membrane using granular material was used. Acoustic and mechanical driving methods both allowed an indirect measurement of the frequency dependent wave velocities and surface tension of the drumhead. | Fisher, Dan | Fisher, Dan | 270 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/Chladni/default.htm | |||||
| 2002-05-17 00:00:00 | Condensed Matter Physics | Josephson Junctions | This experiment examines Josephson junctions and Josephson effect for a moderately large junction and successfully observes the characteristic IV curve and the skewed Fraunhoffer diffraction pattern for the Nb-AlO-NB junction. | El-Sayed, Ibrahim Foster, Adam | El-Sayed, Ibrahim | Foster, Adam | 231 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/Josephson/default.htm | ||||
| 2002-05-17 00:00:00 | Atomic Physics | Stoichiometry Measurements and Imaging Using Nuclear Magnetic Resonance | We used nuclear magnetic resonance to accurately measure the ratio of the number of hydrogen nuclei in pentafluoropropionic acid and 2,2,2-trifluorethanol. This was a precise, non-destructive stoichiometry measurement. | Briesemeister, Dillon Chamberlain, Ryan | Briesemeister, Dillon | Chamberlain, Ryan | 240 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/NMR/default.htm | ||||
| 2002-05-17 00:00:00 | Optics | Measurement of Wavefront Tilt | I observed and measured the wander of a He-Ne laser beam centroid due to the beam passing through a turbulent area of atmosphere created by a heat source. The tilt, or distortion, of the centroid was measured using an adaptation of a double-split beam Mach-Zehnder interferometer. | Roth, Mitch | Roth, Mitch | 252 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/AdaptiveOptics/default.htm | |||||
| 2002-05-17 00:00:00 | Nonlinear Systems | Study of Water Jets by Laser Doppler Velocimetry | A Laser Doppler Velocimetry (LDV) system was used to study the velocity distribution of atomized water particles in an air jet. The data gathered showed that the LDV system accurately reports the velocity of both a solid surface and a water jet. | Moody, Nick Rice, Steven | Moody, Nick | Rice, Steven | 281 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/LDV/default.htm | ||||
| 2002-05-17 00:00:00 | Nonlinear Systems | Measurement of Atmospheric Turbulence | This experiment explored the structure of convective turbulence by measuring the behavior of laser light passing through zones of thermal convection. We tracked spatial deviations of a laser beam from its rest position after passing it over a heat source. Analysis of the frequency dependence of the deviations allowed us to calculate Rayleighs number and to verify Kolmogorov?s ?5/3 power law relation for turbulent systems. | Larson, Derek Merkey, Brian | Larson, Derek | Merkey, Brian | 282 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/Turbulence/default.htm | ||||
| 2002-05-17 00:00:00 | Atomic Physics | Impurities and the Density of the 3S Metastable State of a He Plasma | This experiment used spectroscopy to measure the density of the 3S metastable state (388.86 nm) and the various impurities of an atmospheric helium plasma. The measurement of this state was unsuccessful but time resolved measurements of the impurities yielded positive results. | Borgert, Kristopher Haupt, Jason | Borgert, Kristopher | Haupt, Jason | 241 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/HePlasma/default.htm | ||||
| 2002-05-17 00:00:00 | Optics | Dynamic Light Scattering to Measure the Diffusion of Polystyrene Spheres | In this experiment, the diffusion coefficient and the hydrodynamic radius of polystyrene microspheres are determined in several solvents. The results behave as predicted. | Jensen, Andrew | Jensen, Andrew | 253 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/LightScattering/default.htm | |||||
| 2002-05-17 00:00:00 | Misc | Distinguishing Cloud-Cloud From Ground-Cloud Lightning Using Three Orthogonal Loop Antennae | Three large-diameter loop coils were mounted with mutually perpendicular axes. These were used to record temporal and orientational changes in the local ground-altitude magnetic field due to lightning during several thunderstorms. Many cloud-ground discharges were identified based on duration between magnetic pulses of their component strokes. | McKenzie, Kenneth Micherl, Joshua | McKenzie, Kenneth | Micherl, Joshua | 290 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/CloudLightning/default.htm | ||||
| 2002-05-17 00:00:00 | Misc | Lightning Detection Network | This project is an attempt to determine the location of lightning strikes using measurements of the associated magnetic field polarization. Using large diameter, mutually perpendicular loop coils, we detected and recorded the changing magnetic fields of lightning strikes at two different locations as far as 100 miles away. | Pinnick, Eric Rogoyski, April | Pinnick, Eric | Rogoyski, April | 291 | File Cabinet | http://mxp.physics.umn.edu/s02/Projects/LightningNetwork/default.htm | ||||
| 2001-05-04 00:00:00 | Optics | Amplitude Measurements from Fresnel Zone Plates | The investigation of Fresnel zone plates constructed out of aluminum foil mounted on stiff foam core was carried out using a microwave generator and a 1N23 microwave diode detector. The locations of the focal points and the intensities at the focal points were measured for different number of zone plates and compared to theory. | Edwards, Nathan Fisher, Daniel | Edwards, Nathan | Fisher, Daniel | 151 | See also report 9352 by Popple and Streets. | File Cabinet | ||||
| 2001-05-04 00:00:00 | Particle Experiments | Analysis of Detector Noise in a High Radiation Environment | A 73-Channel Hybrid Photomultiplier tube with a PIN diode, or Hybrid Photodiodes (HPD) was placed in a Californium 252 source for 115 hours at a flux of 10^6 neutrons / second in order to simulate the conditions it would experience in a Compact Muon Solenoid (CMS). DC response during the radiation was monitored and the HPD was analyzed after the radiation. The radiation did not affect the gain of the HPD but it did diminish the quantum efficiency by approximately 50%. | Johnsen, Justin Uzpen, Brian | Johnsen, Justin | Uzpen, Brian | 121 | File Cabinet | |||||
| 2001-05-04 00:00:00 | Cosmic Ray Experiments | Atmospheric Cerenkov Radiation | In our experiment we explored the effects of extensive air showers and Cerenkov radiation using a CCD camera along side three scintillation detectors with PMTs. We acquired data on separation of detectors versus coincidences for indoor and outdoor settings. We also tried to capture the faint blue light associated with Cerenkov radiation using a CCD. | Dale, Thomas Gens, Zachary | Dale, Thomas | Gens, Zachary | 110 | File Cabinet | http://mxp.physics.umn.edu/s01/projects/acdc/acdc.html | ||||
| 2001-05-04 00:00:00 | Nonlinear Systems | Study of Turbulence in Couette-Taylor Flows Using Laser Doppler Interferometry | Measurements of the fluid velocity in a rotating fluid reveal distinct transitions as the Reynolds number is increased, each of which adds a new frequency to the velocity spectrum. The observations found here agree with the results of a similar experiment done by Gollub and Swinney which disagree with the Landau model for the onset of turbulence. | Baisch, Nathan Roberts, John | Baisch, Nathan | Roberts, John | 182 | File Cabinet | |||||
| 2001-05-04 00:00:00 | Optics | Photon Counting Statistics for Timescales Longer and Shorter than Laser Coherence Time | Purpose is to measure the statistical distribution of photons emitted from a laser on timescales longer and shorter than the laser?s coherence time (tc). We can simulate the behavior of a laser on this timescale by sending the beam through a spinning ground glass disk. The second part involves obtaining an estimate for the coherence length of a He-Ne laser. | Stromberg, Ryan Rewey, Jeremy | Stromberg, Ryan | Rewey, Jeremy | 150 | File Cabinet | http://mxp.physics.umn.edu/s01/Projects/Photon/ | ||||
| 2001-05-04 00:00:00 | Condensed Matter Physics | Investigation of Liquid Crystals Using Depolarized Light Microscopy | In this experiment, I have observed an effect occurring in Smectic A liquid crystal films. In particular, the effect in question is a non-zero angle of tilt of the molecules in the surface layers of the film. To measure the orientation of the molecules, I have used a technique relying on the anisotropic optical properties of the liquid crystal molecules. I succeeded in verifying that this effect does exist. Also, it seems that the strength of the interaction between the surface layers decreases with increasing film thickness and increasing temperature. However, the exact mechanism causing this effect is still somewhat unclear. | Berezovsky, Jesse | Berezovsky, Jesse | 130 | File Cabinet | http://mxp.physics.umn.edu/s01/Projects/liqxta/ | |||||
| 2001-05-04 00:00:00 | Nonlinear Systems | Elucidation of Granular Jamming in a 2D Hopper | Granular flow was examined in two-dimensional and three-dimensional hoppers. Jamming probability profiles were established for monodispersed granular systems consisting of either 3 mm or 5 mm glass beads in both a two-dimensional and three-dimensional hoppers. Similar profiles were also found for varying polydispersed hoppers with mixtures of 3 mm and 5 mm glass beads in a two / three-dimensional hopper. The presented results support the previous work with two-dimensional hoppers. However, three-dimensional hoppers and binary mixture results remain unsupported. | Kast, David Song, Jeeseon | Kast, David | Song, Jeeseon | 180 | File Cabinet | |||||
| 2001-05-04 00:00:00 | Condensed Matter Physics | Measuring the Fermi Level and Stokes' Shift of Variously Doped Samples of GaAs | We attempted to find the shift in Fermi levels in samples of GaAs with 1E14, 1E16 and 1E18 carriers per cm^3. We predicted the Fermi levels for these samples to be 0.52 meV, 2.42 meV and 52.2 meV, respectively. We were only able to detect the Stokes Shift for the 1E18 sample, which we found to be 51 +/- 1 meV, about 1 standard deviation from the calculated value for the Fermi energy of the 1E18 sample. We also measured the density of carriers to be 2.7x10^18 electrons per cm^3. | Pint, John Stevens, Jeff | Pint, John | Stevens, Jeff | 131 | File Cabinet | http://mxp.physics.umn.edu/s01/Projects/BandGap/ | ||||
| 2001-05-04 00:00:00 | Condensed Matter Physics | CoO Growth in Co/Ag Films | This experiment examines the oxidation growth on cobalt samples even with the presence of a silver overlayer. Vibrating sample magnetometry was used to determine the thickness of the DC magnetron sputtered films. | Fister, Tim | Fister, Tim | 132 | File Cabinet | http://mxp.physics.umn.edu/s01/Projects/cobaltfilms/ | |||||
| 2001-05-04 00:00:00 | Particle Experiments | Measurement of Muon Lifetime and Cosmic Ray Properties | In this experiment, we used liquid organic scintillator to measure the lifetime and the mass of the muon with data collected from cosmic ray showers. We determined the lifetime with a QVt pulse analyzer in t-mode to bin the times between a muon entry and its decay in the scintillator. Our final data was a plot of the decay rate vs. bin number. From that curve, we calculated the muon lifetime to be 2.16 +/- 0.15 ms. To measure the mass, we switched the QVt to q-mode to record the energies of electrons produced during muon decay. With the maximum electron energy value, we could calculate the muon rest mass to be 138 +/- 27 MeV. | Hansen, Angela Kavic, Michael | Hansen, Angela | Kavic, Michael | 120 | File Cabinet | http://mxp.physics.umn.edu/s01/Projects/Muon/ | ||||
| 2001-05-04 00:00:00 | Misc | Period Measurements of Red Variable Stars in Infrared | The photometry of infrared variable stars (POIVS) is designed to observe variable stars in the infrared. A photodiode with a large amplifier circuit connected to a multimeter was attached to an f/10 8? Celestron Schmidt-Cassegrain telescope. Several Mira-type variable stars in the 0.8 ? 1.7 um wavelength region were studied. | Alden Jr, Robert Peshman, Nicholas | Alden Jr, Robert | Peshman, Nicholas | 190 | File Cabinet | http://peshman.topcities.com/POIVS.htm | ||||
| 2001-05-04 00:00:00 | Condensed Matter Physics | Measurement of PbWO4 Emission Spectrum as a Function of Time | This experiment measured the emission spectrum of various lead tungstate (PbWO4) crystals as a function of time after UV excitation. The experimental apparatus consisted of the crystal that was being tested sandwiched between a trigger photodiode and a monochrometer with a PMT. The crystal was excited by a nitrogen laser and data collection was automated with a stepper motor controlling the monochromator?s grating and a digitial osciolloscope collecting and averaging the data before it was sent to a PC. From the data we were able to estimate the lifetime of the meta-stable states involved in the scintillation process and we were able to see the effects of the impurities in the crystal. | Johnson, Chad | Johnson, Chad | 133 | File Cabinet | ||||||
| 2001-05-04 00:00:00 | Nonlinear Systems | Complex Behavior of a Forced Harmonic Oscillator | The chaotic behavior of a forced harmonic oscillator consisting of a current carrying wire in a magnetic field, driven by a Lorentz force, was studied. Measurements of the oscillations of the wire were made using a single coil guitar pickup. The response of the wire as a function of driving frequency and amplitude was measured and oscillations in multiple dimensions and the phase response in the chaotic region were analyzed. Duffing?s equation for a nonlinear forced oscillator with constant damping was used to analyze the data. | Kane, Daniel Powell, Adam | Kane, Daniel | Powell, Adam | 181 | See also report 9480 by Fain and Silverman. | File Cabinet | http://mxp.physics.umn.edu/s01/Projects/ChaosOsc/ | Continuation of project 9480 by Fain and Silverman. | ||
| 2000-05-05 00:00:00 | Condensed Matter Physics | Determination of the Temperature-Dependent Superfluid Density of Liquid Helium and Investigation of Fourth Sound Resonance in a Porous Medium | A driven torsion oscillator was packed with jeweler?s rouge and saturated with liquid helium was cooled below the lambda point. The resonant frequencies of the oscillator were analyzed to determine the superfluid fraction of the helium sample as a function of temperature to a precision of 0.6%. A fourth sound mode of the system was observed at 223.44 +/- 0.01 Hz. | Moon, Christopher Sankey, Jack | Moon, Christopher | Sankey, Jack | 30 | File Cabinet | |||||
| 2000-05-05 00:00:00 | Condensed Matter Physics | Mechanical Modeling of Wave Propagation Through Ordered and Disordered Media | Wave propagation through different media can be modeled using the Kronig-Penny potential field. This model predicts two phenomena which are examined in this experiment: The transmission of certain frequency bands and Anderson Localization. Both phenomenons were observed with this model, which consisted of a wire with masses spaced both periodically, driven by an oscillator. The spacing between the band gaps was measured to be 530 +/- 14 Hz. This was 5.6% or about one standard deviation off from the calculated value. Localization was observed in a slightly disordered system. | Peterson, Jacob Umhoefer, Hans | Peterson, Jacob | Umhoefer, Hans | 31 | Motion track with guitar pickup | File Cabinet | ||||
| 2000-05-05 00:00:00 | Condensed Matter Physics | Measurement of the Width of and Energy Levels of AlGaAs / GaAs Quantum Wells | The optical properties of two different quantum well hetrostructures were examined using photoluminescence and spectral absorption techniques. The width and energy levels of the quantum wells were found from the wavelength of the emitted light. The width of both samples was found to be 99.75 +/- 0.04 Angstrom and the wells were calculated to contain three heavy hole energy levels and two light hole and electron levels. Only the first energy levels of the wells were observed. | Quisno, Alice Schuetz, Joseph | Quisno, Alice | Schuetz, Joseph | 32 | File Cabinet | |||||
| 2000-05-05 00:00:00 | Atomic Physics | Observation of the Optogalvanic Effect in Neon Gas | In this experiment, optogalvanic spectroscopy was used to determine the emission lines of neon. There are fourteen predicted emission lines due to transitions from the first and second excited state of neon. Four emission lines were detected at 534 +/- 2 nm, 614.2 +/- 2.0 nm, 626.8 +/- 2.0 nm and 633 +/- 2 nm. This experiment was limited due to the resolution of the monochrometer used to select the absorption lines of neon and the poor light source. | Grocholski, Brent Topp, Paytre | Grocholski, Brent | Topp, Paytre | 40 | File Cabinet | |||||
| 2000-05-05 00:00:00 | Atomic Physics | Population Density Measurement of Excited States in an Argon Plasma | This experiment measured the densities of the two metastable and the two resonant 4s states in an RF induced plasma. Spectral analysis was used to measure the plasma absorption of incident light and from the power of the absorption peak the density of the metastable and resonant 4s states was determined. Only two of the lines could be determined, the 738.4 nm and the 794.8 nm lines, and corresponding state densities were calculated. | Eppelheimer, Carrie Kuzma, Matt | Eppelheimer, Carrie | Kuzma, Matt | 41 | File Cabinet | |||||
| 2000-05-05 00:00:00 | Optics | Narrow-Band Tunable Diode Laser System with Grating Feedback | This project consists of the construction of a narrow-band tunable diode laser system using grating feedback and temperature control with injection current control to control the frequency of the laser. This allows the user to continuously tune the diode laser over a range of about 10 to 30 nm for a given temperature. In addition, the temperature of the diode can also be changed which shifts the entire range by about 0.25 nm / C, which allows the laser to be continuously tuned over a very large range. The system can produce about 5 mW of power with a line width of several hundred kHz. | Sherwood, Brain | Sherwood, Brain | 50 | File Cabinet | ||||||
| 2000-05-05 00:00:00 | Optics | Measurements of Spin Lifetimes in Optically Pumped Gallium Arsenide | We measure directly the spin lifetime in 10^16 doped n-type GaAs in the absence of an applied magnetic field. We estimate the lifetime T2* for a non-zero magnetic field using a model of the dynamics of the excited spins. We find lifetimes of 41.5 +/- 1.0 ns and ~10 ns for the zero field and the 325 gauss field cases, respectively. The non-zero field data yields a value of 0.5 +/- 0.1 for the electron g-factor, which is in agreement with literature values. | Marrone, Dan | Marrone, Dan | 51 | File Cabinet | ||||||
| 2000-05-05 00:00:00 | BioPhysics | Apparatus and Procedure for Measuring Changes in Young?s Modulus of Muscle Cells During Contraction | This is a preliminary experiment that will prepare us to investigate the crossbridge theory of muscular contraction. Using a rubber band and chemical freezing to simulate a contracting muscle cell, we studied how the Young?s Modulus varied over time. According to our results, Young?s Modulus did vary over time but the changes were too random to merit meaningful interpretation. This could result from either assuming a linear fit for what may not be a linear system or because we did not use enough data points for a full analysis. | Kean, Sam Wacker, Dave | Kean, Sam | Wacker, Dave | 60 | File Cabinet | |||||
| 2000-05-05 00:00:00 | Acoustic | Measurement of the Attenuation of Sound Due to Humidity and the Calculation of the Speed of Sound in a Gas of Changing Molecular Weight | This project measures the speed of sound when we vary the molecular weight of the gas the sound is propagating through by changing the concentration of Helium in air. We will also examine the peak widths of the resonance curves created by the standing waves in our tube as we change the relative humidity of the air in the tube and compare them with the data in the CRC Handbook. | Jenicek, Scott Olsen, Chris | Jenicek, Scott | Olsen, Chris | 70 | File Cabinet | http://mxp.physics.umn.edu/W00/Projects/soundwaves/default.htm | ||||
| 2000-05-05 00:00:00 | Nonlinear Systems | A Macroscopic Physical Model of Vortex Pinning in a Type II Superconductor | A macroscopic physical model was constructed where freely sliding magnets on a plane represent vortices, fixed magnets on an offset plane represent pinning sites and gravity represents driving force due to an external field. Critical angle, i.e., the angle at which a free magnet will be released from pinning) was analyzed and measured and related to computer predictions. Remarks are made regarding the range and significant limitations of this model. | Abbas, Jeff Heckel, Titus | Abbas, Jeff | Heckel, Titus | 80 | Inclined Vortex Plane | File Cabinet | ||||
| 1999-06-09 00:00:00 | Nonlinear Systems | Influence of Diffraction and Mesoscopic Disorder on Vortex Dynamics | Under the guise of vortex interaction, we modeled tornadic interaction with a blender and a DC motor in a tub of rheoscopic fluid. Our hypothesis of a figure eight surface interaction was not proven to be true, but with more experimentation and better design, it may prove fruitful. However, our other hypothesis that a "diffraction" slit would affect the interaction did prove true and in interesting, unexpected ways. | Beauchane, Laura Grundstrom, Erika | Beauchane, Laura | Grundstrom, Erika | 9980 | File Cabinet | |||||
| 1999-06-09 00:00:00 | Condensed Matter Physics | Effects of Molecular Packing on Surface Tension | The effect of molecular packing on surface tension was studied. By direct measuring the surface tension of some thin films, we were able to establish some properties of the molecular packing of the film. The surface tension measurements were done using the methods and equipment designed by Stoebe et al. In particular, the study was conducted using freestanding liquid crystal films that exhibited a SMCA-alpha phase. Though we were not able to complete the study, we expect that CH2 and CH3 groups populate the film interface of "TFM". | Halverson, Mark | Halverson, Mark | 9930 | File Cabinet | ||||||
| 1999-06-09 00:00:00 | Condensed Matter Physics | Magnetic Cooling of a Paramagnetic Salt | The goal of this experiment is to design and build the necessary apparatus to achieve temperatures on the order of 0.01K using paramagnetic salts. Our project consisted of obtaining, designing and constructing suitable dewars and stands, a vacuum can and a system of solenoids for the cooling and temperature measurement. We were able to find that the solenoids we built were well suited for our purposes. | Durand, Adrian Skinner, Joseph | Durand, Adrian | Skinner, Joseph | 9931 | Dewar Stand, Solenoids | File Cabinet | http://methods.physics.umn.edu/s99/Projects/cooling/default.htm | |||
| 1999-06-09 00:00:00 | Particle Experiments | Measuring the Concentration of Radon (222) in Rainwater during a Rainfall | A measurement of the concentration of Radon (222) in rainwater was carried out. Using properties of radioactive decay, we extrapolate back to the relative amount of Radon (222) in our sample by measuring the number of gamma decays produced by Radon daughter isotopes. A phototube, a sodium iodine crystal, some interface circuitry and a personal computer were used to measure and display the energy spectrum of our samples. | Gaalas, John Peffer, Phil | Gaalas, John | Peffer, Phil | 9920 | Integrator (pulse stretcher), trigger and interface circuit | File Cabinet | ||||
| 1999-06-09 00:00:00 | Particle Experiments | Characterization of the CLEO III RICH Photo-Detector | In this project, we characterized the effects of high-energy particles on a multi-wire proportional chamber (MWPC) used in the CLEO III RICH photon detection array. Using one of the MWPC's from the detector array, we investigated the effects of extensive exposure on the cathode pads. Though the data was inconclusive, our study of the materials involved eludes to the fact that a breakdown in the efficiency of the MWPC in question would occur within a short time. | Braun, Thomas Wolfe, Jason | Braun, Thomas | Wolfe, Jason | 9921 | File Cabinet | http://methods.physics.umn.edu/s99/Projects/multiwpc/default.htm | ||||
| 1999-06-09 00:00:00 | Particle Experiments | Characterization and Analysis of the Dark Pulse Output of Hybrid Photo-diodes | Hybrid Photo Diodes (HPD) exhibit noise fluctuations without incident light. This noise has been determined to be predominantly (at room temperature) thermionic emissions in the photo cathode layer. This emission can be described by the Richardson-Dushman equation with corrections due to the high voltage induced electric field, temperature dependence of the work function and reflections of the photoelectrons at the photo cathode surface. In addition, electrostatic discharges in the HPD due to the high voltage produce observable radiation that also leads to dark noise. | Fisher, Wade Savage, Chris | Fisher, Wade | Savage, Chris | 9922 | File Cabinet | 85.60.Gz, 79.40.+z, 29.40.Vj | http://www.hep.umn.edu/us-cms/hcal/Noise/ | |||
| 1999-06-09 00:00:00 | Misc | Measuring the Magnetic Fields of Lightning with a Search Coil Magnetometer | We investigated the magnetic field fluctuations induced by lightning strokes with a search coil magnetometer. After construction of the coil, we calibrated its response and measurements were made of the noise present in a number of locations. When the likelihood of observing natural lightning was small, we measured artificial sparks generated by a Wimshurst machine. Measurement of lightning later became possible and the field changes we observed, about tens of nanoteslas, closely matched previously published data. | Dolney, Derek Onken, Christopher | Dolney, Derek | Onken, Christopher | 9990 | Search Coil | File Cabinet | http://methods.physics.umn.edu/s99/Projects/searchcoil/default.htm | |||
| 1998-06-08 00:00:00 | Misc | Wind Tunnel for the Verification of Computational Fluid Dynamic Models of Heat Sinks | The purpose of the wind tunnel experiment is to verify the performance of heat sinks that have been modeled using a computational fluid dynamics (CFD) program. The primary performance parameter to be verified will be the total heat dissipated by the heat sink for a given maximum temperature, although the following parameters will be measured: Temperature distribution in the heat sink and temperature, pressure, and velocity profile of the air surrounding the heat sink. This report outlines the design of the wind tunnel. | Strei, David | Strei, David | 9890 | File Cabinet | ||||||
| 1998-06-08 00:00:00 | Condensed Matter Physics | Resonant Peaks in Metal Rods Due to Magnetostriction of Nickel | Magnetically induced vibration in metal rods were examined to find the speed of sound in aluminum and stainless steel. This was accomplished with the use of a capacitance bridge to measure efficiently and a nickel core to drive it into magnetostriction. The results suggest that this method is sufficiently good to justify future research. Also, the widths of the peaks were measured to find Q. | Becker, Bernard Gelhouse, Raymond | Becker, Bernard | Gelhouse, Raymond | 9830 | File Cabinet | |||||
| 1998-06-08 00:00:00 | Condensed Matter Physics | Indirect Electron Tunneling | This project measures the indirect tunneling of electrons in diodes at various temperatures. The phonons involved in the interaction will be identified and their energies will be compared to theoretical calculations. | Enz, Michael | Enz, Michael | 9831 | File Cabinet | http://methods.physics.umn.edu/s98/projects/menz/default.asp | |||||
| 1998-06-08 00:00:00 | Optics | Weak Localization Due to Microwave Scattering | Our experiment was designed to look for quantum interference, or weak localization, in a one-dimensional system. This is done using a large number of quartz scatterers on a 9 GHz radiation in a wave guide. We noticed a power dip which may have been this effect, but there was also an anomaly in the region which we could not account for. | Alvarez, Conrado Hietala, Justin | Alvarez, Conrado | Hietala, Justin | 9850 | File Cabinet | |||||
| 1997-06-07 00:00:00 | Condensed Matter Physics | Magnetic Decay in Thin Ferrous Oxide Films Due to Field Interactions | The ubiquitous magnetic decay in iron oxide particul thin-films was analyzed. After initially being set to a high energy configuration, many magnetic systems exhibit a slow relaxation back to a stable low energy state through a quasi-logarithmic decay or magnetic aftereffect. This experiment tried to confirm a quasi-logarithmic decay model. To map the magnetic decay, the experiment measured the remnant magnetization of a calibrated disk over several time decades using an integrator circuit. | Eames, Peter Hill, Bradford | Eames, Peter | Hill, Bradford | 9732 | File Cabinet | 43.38 | ||||
| 1997-06-07 00:00:00 | Misc | High Vacuum Pressure Measurement Based on the Motion of a Magnetically Levitated Particle | This experiment analyses the relationship between transient decay of a harmonic oscillator and the pressure of a gas in which it moves. The experimental setup consists of a permamagnet levitating a diamagnetic particle of bismuth inside of a vacuum system to allow for pressure alteration. A laser beam reflected off the particle is cast onto a photodiode, which is connected to a computer for data analysis. The experiment confirmed that the decay is pressure independent except at very high vacuums where the mean free path of the gas is comparable to the oscillatory amplitude of the particle. | Clayton, Steven Plowman, Jason | Clayton, Steven | Plowman, Jason | 9791 | File Cabinet | |||||
| 1997-06-07 00:00:00 | Misc | Electromagnetic Wave Propagation Through Cold Plasma | In a plasma electrons will harmonically oscillate at a constant frequency, known as the plasma frequency. It was our goal to measure the plasma frequency and electron density at various electron densities. We were not successful in measuring either quantity, however attempts yielded a convenient method to generate a stable plasma. | Speakman, Ben Stenzel, Ben | Speakman, Ben | Stenzel, Ben | 9790 | File Cabinet | 52.4 | http://methods.physics.umn.edu/s97/Projects/Plasma/index.htm | |||
| 1997-06-07 00:00:00 | Acoustic | Cavitation Via Sonoluminescence and Frequency Components | This investigation focused on experimentally determining acoustic cavitation distributions from sonoluminescence and frequency components of a small test cell for the megasonic range of interest. | Zuniga, Robert | Zuniga, Robert | 9770 | File Cabinet | 43.25 | http://methods.physics.umn.edu/s97/Projects/sono/index.htm | ||||
| 1997-06-07 00:00:00 | Optics | Laser Doppler Velocimetry | Laser Doppler Velocimetry (LDV) or Laser Doppler Anemometry enables non-intrusive measurements of dynamical fluid flow. It uses two coherent, collimated beams that intersect at the region of measurement. Small reflective particles entering this volume will scatter light that is detected and analyzed for its frequency, which corresponds to the Doppler effect on the scattered light due to the motion of particles. For this experiment, a Dual Beam LDV system was built. | Schram, Melissa Yam, Patrick | Schram, Melissa | Yam, Patrick | 9750 | File Cabinet | http://methods.physics.umn.edu/s97/Projects/chaos/index.htm | ||||
| 1997-06-07 00:00:00 | Condensed Matter Physics | Measurement of the Velocity of Second Sound in He4 Near the Lambda Point | For this experiment we utilized the resonance method in which we employed the use of a strain gauge coupled to an Allen Bradeley resistor as a heat generator and standard heat detector located at both ends of a cylindrical cavity. | Amini, Hassib Torikoshi, Kenichi | Amini, Hassib | Torikoshi, Kenichi | 9733 | File Cabinet | http://methods.physics.umn.edu/s97/Projects/Hesound/index.htm | ||||
| 1997-06-07 00:00:00 | Condensed Matter Physics | Measurement of He3-He4 Ratio | An acoustic device with an automatic feedback gain control was constructed to measure the concentration of a 3He - 4He gas mixture. The system was tested in air and in a Helium mixture. | Engebretson, Dave Effengerger, Allen | Engebretson, Dave | Effengerger, Allen | 9731 | File Cabinet | 67.60.-g | http://methods.physics.umn.edu/s97/Projects/heratio/index.htm | |||
| 1997-06-07 00:00:00 | Condensed Matter Physics | Low Energy Electron Diffraction | Two LEED images of the Si[111]7x7 surface of silicon are achieved using a hemispherical LEED system. Analysis revealed both three- and sixfold symmetry in the surface. | Greissen, Christopher Huber, Jon A | Greissen, Christopher | Huber, Jon A | 9730 | File Cabinet | 61.14 | http://methods.physics.umn.edu/s97/Projects/LEED/index.htm | |||
| 1997-06-07 00:00:00 | Particle Experiments | The Average Lifetime of a Cosmic Ray Muon | This project measured the average lifetime of the cosmic ray muons incident on the earth. The muons were captured in a container filled with liquid scintillator fluid. This fluid gives off a light pulse when a pion enters and a muon is created; it also produces a light pulse when that muon decays. A photomulitplier tube detects the light pulses and the time interval between pulses is measured with a computer. | Bram, Michael Stone, William | Bram, Michael | Stone, William | 9720 | File Cabinet | 14.6 | ||||
| 1997-06-07 00:00:00 | Atomic Physics | Electron Spin Resonance | Electron Spin Resonance (ESR) is the study of induced transitions of electrons between energy levels in an applied electromagnetic field. The Lande g-factor is a constant of proportionality (approximately 2, but differing for individual substances) in the determination of the energy between these electronic levels and it can be measured through knowing the frequency and amplitude of the applied magnetic field. We measured the g-factor for DPPH and Cu2+. | Webster, Jennifer Todd, Jeremy | Webster, Jennifer | Todd, Jeremy | 9740 | File Cabinet | 33.35 | http://methods.physics.umn.edu/s97/Projects/ESR/index.htm | |||
| 1996-06-06 00:00:00 | Condensed Matter Physics | Magnetic Properties of Ferrihydrate Cores | Ferrihydrate cores found naturally occurring in horse spleen exhibit magnetic ordering structure. The antiferromagnetic structure exhibited at low temperature is overcome at the blocking temperature as thermal energy overcomes anisotropy. The antiferromagnetic to superparamagnetic transition has been observed in susceptibility measurements. | Godfrey, Ryan | Godfrey, Ryan | 9635 | File Cabinet | 75.50.Gg | |||||
| 1996-06-06 00:00:00 | Optics | Measurement of Surface Roughness by Laser Speckle Interference | Laser Speckle occurs from the interference of coherent light when reflected from a rough surface. We attempt to confirm the relationship between surface roughness and characteristics of the resulting Speckle pattern. Using a laser spectral bandwidth of 2.54 x 10^-5 m^-1, it was shown that the contrast of a singly-scattered Speckle pattern is an insensitive measure of the surface roughness. Increasing the laser bandwidth would establish the contrast as a more sensitive measurement technique. Using targets such as sandpaper scratched aluminum and micro-abrasive films, the Speckle patterns were acquired with a CCD camera and analyzed with a computer. | Kurzweg, Jennifer Voelz, Vincent | Kurzweg, Jennifer | Voelz, Vincent | 9651 | File Cabinet | 42.30.M | ||||
| 1996-06-06 00:00:00 | Misc | Measurement of the Universal Gravitational Constant, G | This experiment was designed to measure the gravitational constant, G, using a torsion balance and a negative feedback circuit. The setup, a modern version of the Cavendish experiment, generated a feedback current based on the angular position of the torsion balance. The current, when driven through a coil, produced a magnetic torque that acted upon a magnet attached to the rod and restored it to its equilibrium position, thus canceling the gravitational and rotational torque. | Beheshti, Afshin Lyke, James | Beheshti, Afshin | Lyke, James | 9691 | File Cabinet | 04.80.-y | http://methods.physics.umn.edu/s96/abstracts00.htm#G | |||
| 1996-06-06 00:00:00 | Misc | Thermomigration of Air Bubbles in a Fluid under Gravity | This experiment is a study of buoyancy force and Marangoni convection as they affect an air bubble injected into oil. The Marangoni effect, or "thermocapillary convection," causes motion due to the differential in surface tension of a bubble created by a temperature gradient in oil. In this experiment, a temperature gradient is used to induce a Marangoni force and balance itself against the buoyancy force. | Becker, Christine Lusson, Randall | Becker, Christine | Lusson, Randall | 9692 | File Cabinet | 44.60.+k | ||||
| 1996-06-06 00:00:00 | Misc | Measurement of the Drag Coefficient at Different Air Velocities | Laminar airflow was directed at a smooth surface (dust-sized roughness) nylon ball to see if the drag coefficient changes with various air velocities. | Nguyen, Canh | Nguyen, Canh | 9693 | File Cabinet | 83.50.W | |||||
| 1996-06-06 00:00:00 | Condensed Matter Physics | Determination of Isotropic Ratio of 3He-4He Gas | An acoustic device, utilizing an automatic gain feedback loop to determine the resonant frequency of a 3He / 4He gas mixture, was constructed to measure the 3He concentration. The system was tested in air, then calibrated in pure 4He. Given the right conditions, the outcome could have been easily measured with high accuracy. | Heck, David Kou, Vince | Heck, David | Kou, Vince | 9634 | File Cabinet | 67.60.-g | ||||
| 1996-06-06 00:00:00 | Condensed Matter Physics | Dry, High-Gradient Magnetic Separation of Magnetite Particles from Impurities in Iron Ore | Gravity driven fine-ground iron ore is passed through a high-gradient magnetic field. The field gradient gives the magnetic magnetite a momentum perpendicular to the flow of the feed, separating it from nonmagnetic impurities. | Dahmes, Bryan Taddei, Phillip | Dahmes, Bryan | Taddei, Phillip | 9631 | File Cabinet | 41.20.-q | http://methods.physics.umn.edu/s96/abstracts00.htm#ore | |||
| 1996-06-06 00:00:00 | Condensed Matter Physics | Spectroscopic Measurement of the Semiconductor Energy Gap | An automated system for measuring the energy gap of semiconductors using optical excitation is presented. The transmission spectrum and indirect-gap transition were observed for Silicon. The energy gap was found to be 1.168 +/- 0.007 eV. | Gaalaas, Joe Thain, Douglas | Gaalaas, Joe | Thain, Douglas | 9632 | File Cabinet | 42.70.Nq | ||||
| 1996-06-06 00:00:00 | Condensed Matter Physics | The Meissner Effect in Superconductors | Temperature dependence of the magnetic flux penetration depth into YBa2Cu3O7, a type II semiconductor, below its Tc was measured by placing the sample within a pair of concentric coils and observing the effect of flux penetration on the mutual inductance of the coils. | Wald, Thomas Zweber, Peter | Wald, Thomas | Zweber, Peter | 9633 | File Cabinet | 75.5 | ||||
| 1996-06-06 00:00:00 | Condensed Matter Physics | Construction of an Ion Detector for a Mass Spectrometer on a Chip | A one dimensional ion detector is under development for a micro mass spectrometer (MMS) at the University of Minnesota. Two possible devices can be used: the first one is an array of micro Faraday cups built on a silicon wafer, or a commercial charge couple device (CCD). The array was designed and built at the Micro Technology Laboratory and two CCDs were purchased. A vacuum chamber with a 4 probe wafer testing, x-y-z displacement and ion gun incorporated was built and the devices were tested under ion bombardment to study their sensitivity. | Diaz, Jorge | Diaz, Jorge | 9636 | File Cabinet | ||||||
| 1995-06-06 00:00:00 | Misc | Magnetic Field Accelerators: Coilgun Efficiency Study / Parameters Determining Energy Transfer | A desktop coilgun apparatus was built to test predictions of the simplified current loop model. Energy supply calculations and impulse approximations were verified by measuring RLC discharge waveforms. The prediction that the efficiency of energy transfer is proportional to voltage squared was verified to within 9.5% using a linear fit. Finally, the model's failure to accurately predict spatial parameters describing coilgun operation was demonstrated. | Zellinger, Fred Bedrosian, Paul | Zellinger, Fred | Bedrosian, Paul | 9591 | File Cabinet | |||||
| 1995-06-06 00:00:00 | Misc | Development of a PC-based Control System for a Total Cylinder Sampling Experiment | We developed, tested, and preliminarily timed a PC-based system to control a Total Cylinder Sampling Experiment to be performed on a John Deere 4045 diesel engine. The experiment would take crankangle resolved particle concentration and size distribution measurements of the combusting cylinder contents with a Condensation Nucleus Counter (CNC), and an Electrical Aerosol Analyzer (EAA). The control system is complete, functional, and with further timing, ready to take data. This paper reports the experimental control system developed. | Spears, Matthew Johnson, Jason | Spears, Matthew | Johnson, Jason | 9590 | File Cabinet | |||||
| 1995-06-06 00:00:00 | Particle Experiments | Radon Detection Using Ionized Air Technology | During the ten-week quarter we built and studied an Ionized Air Detector (IAD) to monitor Radon gas concentrations following a similar experiment by R.D. Bolton at Los Alamos National Laboratory. Relative concentration measurements were made and validate expected response. We determined that radon concentration in a room was dependent more on air circulation than barometric pressure changes. However, in the room monitored, we considered both of these factors to contribute a very small change, about +/- 0.05 pCi/L. | Rogers, Scott Madsen, Shannon | Rogers, Scott | Madsen, Shannon | 9520 | File Cabinet | |||||
| 1995-06-06 00:00:00 | Acoustic | Sonoluminescence: Trapping Air Bubbles in a Resonant Sphere of Water | Bubbles of air trapped in a sphere of water are resonated with a standing sound wave. They behave in some ways similar to those observed by sonoluminescence researchers, and in many ways contradictory to those observations or to common sense. | Siders, Ryan | Siders, Ryan | 9570 | File Cabinet | ||||||
| 1995-06-06 00:00:00 | Misc | A Non-Invasive Measurement of the Plasma Properties of a Fluorescent Light Bulb | We studied the spectrum of various signals generated by a standard Sylvania one inch by 48 inch fluorescent bulb in the presence of a DC induced linear electric field along the long axis of the bulb. This 140 V DC to 300 V DC electric potential yielded a spatially dependent periodic signal that was detectable by a movable receiving capacitive antenna consisting of two copper leads tuned to the expected plasma frequency. We performed a spatial analysis on a prominent signal discovered at a frequency of 690 Hz to define its structure. We found a linear increase in signal strength as the antenna traveled from the cathode to the anode. | Bennet, T R. Scott, T J. | Bennet, T R. | Scott, T J. | 9592 | File Cabinet | |||||
| 1995-06-06 00:00:00 | Condensed Matter Physics | High Temperature Superconductivity and the Meissner Effect | We studied the Meissner effect and the subsequent penetration depth of the remaining magnetic field in a sample of a high Tc superconducting material. | Brown, Heather Dunsmore, Bruce | Brown, Heather | Dunsmore, Bruce | 9530 | File Cabinet | |||||
| 1995-06-06 00:00:00 | Nonlinear Systems | The Staebler-Wronski Effect in n-Type Hydrogenated Amorphous Silicon | The Staebler-Wronski effect has been studied in 4 E-3 PH3 / SiH4 doped and intrinsic samples of a-Si:H. Good agreement with a T^1/3 kinetic model was obtained and approximate decay constants were found. A saturation time of 20 hours of exposure was found for the intrinsic sample and a lower limit of 24 hours was placed on the saturation time of the doped sample. | Sabatke, D S. Tabak, E A. | Sabatke, D S. | Tabak, E A. | 9580 | File Cabinet | |||||
| 1995-06-06 00:00:00 | Acoustic | Transitions to Sonoluminescence | The transition to single bubble sonoluminescence is a very enigmatic phenomenon. We have discovered that achieving bubble trapping does not imply that sonoluminescence is forthcoming. We managed to achieve stable bubble trapping, yet were unable to make the final step and obtain sonoluminescence. | Carlson, John Huff, Brian | Carlson, John | Huff, Brian | 9571 | File Cabinet | |||||
| 1995-06-06 00:00:00 | Optics | Interactions of Light and Sound | We investigated the diffraction of light by ultrasound using a home built ultrasonic cell (UC) and a commercially manufactured sound absorption apparatus which was filled with either water or mineral oil. Both devices utilized piezoelectric transducers, which produced a traveling wave in the fluid that diffracted incident laser light. We saw diffraction from both devices. By calculation, we verified that our results agreed with the Bragg and Raman Nath diffraction theories. | Fairchild, Hans Fredricksen, Brian | Fairchild, Hans | Fredricksen, Brian | 9552 | File Cabinet | |||||
| 1995-06-06 00:00:00 | Optics | Fabrication of Sub-Micron Gratings | A method of creating sub-micron gratings using Lloyd's Mirror Fringes is described. A set of four gratings were produced first in photoresist, then etched into a quartz substrate. The gratings were examined for accuracy and uniformity. The systematic errors were difficult to eliminate, but the data suggests a high degree of reproducibility. The gratings were found to have a mean period of 0.5893 micrometers with a standard deviation of 0.00016 micrometers. | Pedersen, Paul Elliot, Erin | Pedersen, Paul | Elliot, Erin | 9550 | File Cabinet | |||||
| 1995-06-06 00:00:00 | Particle Experiments | Measurement of the Muon Lifetime and Magnetic Moment | We have measured the lifetime of cosmic ray muons captured in a brass target in the presence of an external magnetic field over a period of several days. Using these values, we have calculated the lifetime of the u+ and u- and also the magnetic moment of the u. | Schablitsky, Steven Stevens, Martin | Schablitsky, Steven | Stevens, Martin | 9521 | File Cabinet | |||||
| 1995-06-06 00:00:00 | Optics | Rayleigh Scattering of Solar Irradiance | The solar spectrum of the sun was measured at different times of the day with a monochromater. The data was then fitted to the process of Rayleigh scattering, with both Planck's blackbody spectrum and data from the CRC handbook as initial intensities. | Christofferson, Blaine Bjoraker, Jeff | Christofferson, Blaine | Bjoraker, Jeff | 9551 | File Cabinet | |||||
| 1995-06-06 00:00:00 | Acoustic | Sonoluminescence: Experimental Sensitivity to Acoustic Phenomena | The authors discuss acoustic phenomena observed in a single apparatus designed for work on single-bubble sonoluminescence. | Christensen, Kurt Siders, Ryan | Christensen, Kurt | Siders, Ryan | 9572 | File Cabinet | |||||
| 1994-01-01 00:00:00 | Condensed Matter Physics | Temperature Dependence of the Gain of an Avalanche Photo Diode | We have studied the gain as a function of temperature of an Advanced Photonix Avalance PhotoDiode (APD). We confirmed that the gain increases with decreasing temperature at a fixed voltage. | Thakur, Qurratulain Yarusso, Laura | Thakur, Qurratulain | Yarusso, Laura | 9433 | File Cabinet | |||||
| 1994-01-01 00:00:00 | Misc | Measurement of the Force Generated by a Rower | In this experiment we measured the force on a rower?s oar by means of strain gauges affixed to the oar shaft. Using this method we were able to determine the force on the water provided by the rower. We also performed our experiment using two different types of oars and concluded that the newer hatchet style oars delivers the rower?s force to the water more efficiently than the older spoon style oars. | Orsted, Fred Pinski, Aaron | Orsted, Fred | Pinski, Aaron | 9491 | File Cabinet | |||||
| 1994-01-01 00:00:00 | Misc | Air Resistance of Bicycle Wheels | Measurements of the power required to spin various bicycle wheels at steady speeds were made to ascertain the air-resistance of the various designs. The area of the spokes / rotating surface appeared to affect the air-resistance most significantly. | Anderson, Scott | Anderson, Scott | 9490 | File Cabinet | ||||||
| 1994-01-01 00:00:00 | Nonlinear Systems | Complex Behavior of a Forced Harmonic Oscillator | We observed an oscillator driven by a Lorentz forcing term and we measured: the response of wire displacement as a function of driving frequency, the harmonic behavior with respect to primary resonance and the associated phase behavior. Throughout our analysis, we assumed that the behavior of the experimental apparatus obeys Duffing's equation. From this we conclude that Duffing's single mode model for a nonlinear forced oscillator with constant damping may not necessarily be an adequate description for the actual observed phenomenon. | Fain, Sean Silverman, Greg | Fain, Sean | Silverman, Greg | 9480 | See also the report by Kane and Powell (0181) continuing this project. | File Cabinet | ||||
| 1994-01-01 00:00:00 | Optics | Time Averaged Holographic Interferometry of a Resonating Handbell | We proposed to observe the nodal patterns of a resonating hand bell by viewing a split-beam transmission hologram made from a vibrating bell. The light reflected from the vibrating bell will interfere with the light from a reference beam. The degree of interference depends on the displacement of the bell from its rest position, which is greatest at the nodes of the vibration. | Chapik, Daniel Walling, Darin | Chapik, Daniel | Walling, Darin | 9451 | File Cabinet | |||||
| 1994-01-01 00:00:00 | Optics | Study of the Faraday Effect | Linearly polarized light propagated through a medium parallel to a magnetic field often experiences a rotation of the plane of polarization by a process known as Faraday effect. This rotation is a property of the strength of the magnetic field and a constant for a given substance, known as the Verdet constant. We verified that the angle of rotation is linear with magnetic field. We also examined the variation of Verdet's Constant with wavelength in the visible portion of the spectrum and water and found a linear relation. | Alferness, Jason Wilkens, Steve | Alferness, Jason | Wilkens, Steve | 9450 | File Cabinet | |||||
| 1994-01-01 00:00:00 | Condensed Matter Physics | Reversibility of Magnetization Using AC Susceptibility | The goal of this project was to develop a method of separating the processes that cause magnetic changes: the "quick" flipping of dipoles and the "slow" rotation of dipoles or group of dipoles. The investigation utilized the properties of AC susceptibility which can be interpreted as the as the derivative of magnetization with respect to applied field. By integrating susceptibility data sweeps, magnetization curves for several materials were generated. | Netzer, Robert | Netzer, Robert | 9431 | File Cabinet | ||||||
| 1994-01-01 00:00:00 | Condensed Matter Physics | Measurement of the Surface Tension of Free-Standing Liquid Crystal Films | The measurement of the surface tension of freestanding 65OBC and 54COOBC liquid crystal thin films was conducted to the methods of Stoebe et al. Using this method, film and surface tension can be determined to a relative standard error of 0.6% and an absolute standard error of 1.1%. The results obtained have been shown to agree with previously existing surface tension data obtained employing entirely different methods. | Debe, Derek | Debe, Derek | 9430 | File Cabinet | ||||||
| 1994-01-01 00:00:00 | Cosmic Ray Experiments | Determination of the Lifetime of the Anti-Muon | A block of lead glass was used to stop cosmic ray muons. An apparatus with coincidence paddles, photomultiplier tubes, a digital scope and a computer were used to collect data of the lifetime of the anti-muon, which makes up 75% of the cosmic ray flux. The measured lifetime was 2.1926 +/- 0.0075 us, comparable to the accepted value of 2.197 us. | Johns, Scott | Johns, Scott | 9411 | File Cabinet | ||||||
| 1994-01-01 00:00:00 | Cosmic Ray Experiments | Determination of the Muon Magnetic Moment | This paper discusses the approach used in the design of an experiment for the determination of the u+ magnetic moment and half-life when captured in solid medium. The complete experimental equipment and the present state of the experiment are discussed. | Gage, Jared Peterson, Thomas | Gage, Jared | Peterson, Thomas | 9410 | File Cabinet | |||||
| 1994-01-01 00:00:00 | Condensed Matter Physics | Viscosity of Magnetorheological Fluids | The viscosity of magnetorehological fluids was measured perpendicular and parallel and as a function of applied magnetic field. A viscometer was designed which was capable of measuring viscosity in many spatial orientations. As predicted, the perpendicular case was found to exhibit a greater increase in viscosity than the parallel case. | Aurit, Gary Erickson, Jason | Aurit, Gary | Erickson, Jason | 9432 | File Cabinet | |||||
| 1994-01-01 00:00:00 | Misc | Determination of the Electron's Charge Using the Milliken Oil Drop Experiment | The charge of an electron was measured by observing the terminal velocities of oil drops under the influence of gravity alone and then with an applied electric field helping or hindering gravity. | Parendo, Shane Moaddeli, Raha | Parendo, Shane | Moaddeli, Raha | 9493 | File Cabinet | |||||
| 1994-01-01 00:00:00 | Particle Experiments | An Experimental Measurement of the Mean Free Muon Lifetime | A thirty-gallon can made from galvanized steel was filled with 10% solution of 1,2,4-trimethylbenzene to serve as a scintillator, and pulses were recorded using NIM discriminators and a constructed timing circuit interfaced with a PC via a prototype card. Data was taken for 88 hours, amassing 75000 counts. From the resultant decay curve, we obtained a value for the mean free muon life time of 2.191 +/- 0.012 us, which is 0.5 sigma from the most recent published value. | Neaton, Jeffrey Tregillis, Ian | Neaton, Jeffrey | Tregillis, Ian | 9420 | File Cabinet | |||||
| 1994-01-01 00:00:00 | Misc | Measurement of G (universal gravitational constant) using a torsion balance. | The purpose of this experiment is to measure G (universal gravitational constant) using a torsion balance with a feedback circuit. This apparatus differs from that used by Cavendish because the torsion beam in prevented from rotating through the use of a feedback circuit. The circuit takes the angular position of the beam to generate current through a coil which produces a magnetic torque on the rod due to a small attached magnet. The torsion beam is held at a fixed position by the varying magnetic torque and rotational torque from the torsion fiber. | Thayer, Dan Anderson, Scott | Thayer, Dan | Anderson, Scott | 9492 | Torsion beam, circuit box | File Cabinet | ||||
| 1993-01-01 00:00:00 | Condensed Matter Physics | Surface Tension as Funct. of Temperature and Thickness of Liquid Xtal Films | An experiment design enabling measurement of surface tension values for freestanding liquid crystal films was developed. The experimental system allows for both temperature and thickness dependence studies of surface tension to be carried out. Surface tension values of 21.7 +/- 1.1 dynes/cm for the 7O.7 compound (at 72.5 degrees Celsius) and 27.1 +/- 1.2 dynes/cm (at 78 degrees Celsius) for the CBOAA compound were obtained, agreeing with previously reported results for these materials. Results for the 65OBC compound were obtained which suggests surface tension is independent of film thickness over a range of 2-100 molecular layers, to within a 4% experimental resolution, with a mean surface tension value of 18.9 dynes/cm. In addition, data for 65OBC collected over a temperature window encompassing both surface and interior SmA-SmB transitions suggest that surface tension varies little with temperature, any variations being less than the 4% resolution of this study. | Mach, Peter | Mach, Peter | 9330 | File Cabinet | ||||||
| 1993-01-01 00:00:00 | Optics | Diffraction of Microwaves and Optical Light by Fresnel Zone Lenses | A study of fresnel zone lenses was conducted with microwaves and lasers. Microwaves were used to examine the intensity contribution of individual fresnel zones at an observation point. The intensity along the axis of fresnel lenses were also studied. The resulting data was used to construct zone lenses for light from a He-Ne laser. | Popple, Tony Streets, Jaena | Popple, Tony | Streets, Jaena | 9352 | See also report 0151 by Edwards and Fisher. | File Cabinet | ||||
| 1993-01-01 00:00:00 | Misc | Disruption of Tornadic Activity | The author discusses the idea of disrupting tornadoes by presenting a simple mathematical model of a tornado, and makes suggestions for improvements which can be made to this model. A qualitative experiment was performed to explore potential methods for tornado disruption, the results of which appear to support the general approach of the model.. | Leppik, Peter | Leppik, Peter | 9394 | File Cabinet | ||||||
| 1993-01-01 00:00:00 | Misc | Temperature Dependence of Ice Crystal Formation | This experiment was an investigation of the temperature dependence of ice-crystal structure by the growth of ice-crystals on a string in a cloud diffusion chamber. Five distinct crystal structures, needles, columns, prisms, plates, and ferns, which grew in the ?40 degrees Celsius to 0 degrees Celsius temperature range were identified, and an average temperature range in which each form was determined. | Sabatke, Chris Fetterly, Ken | Sabatke, Chris | Fetterly, Ken | 9393 | File Cabinet | |||||
| 1993-01-01 00:00:00 | Misc | Measurement of Big G | The measurement of the gravitational constant G, originally made by Sir Henry Cavendish in 1798, has since proved to be an experiment tedious and difficult to replicate. Improvements were made to Cavendish?s original torsion pendulum allowing the experiment to consume less time. The improved ?Electronic Cavendish device? consists of electronic servomechanism that is used to maintain the torsion bar at equilibrium. The voltage or current required for the servomechanism is used to determine G in a short period of time. | Shackelford, Stelios A. Atkins, Derrick | Shackelford, Stelios A. | Atkins, Derrick | 9392 | File Cabinet | |||||
| 1993-01-01 00:00:00 | Misc | Theory and Experiment of Solid Body Collisions | We studied the contact time in solid body collisions. Using an electrical circuit, we measured the contact time in the collisions between a spherical object and a steel plate. A deviation between the prediction and the experimental results was observed. | Shifman, Julia M. Haidos, Steve J. | Shifman, Julia M. | Haidos, Steve J. | 9391 | File Cabinet | |||||
| 1993-01-01 00:00:00 | Misc | Compensating Helmholtz Coils | Used a pair of compensating Helmholtz coil. The coils were suspended to external magnetic field in order to measure the induced current. A test solenoid was then used to determine the sensitivity of the coils to internal magnetic fields. | Knutson, Eric | Knutson, Eric | 9390 | File Cabinet | ||||||
| 1993-01-01 00:00:00 | Acoustic | Characteristics of Sound Waves in Solid Granular Materials | Since sound waves need a medium to propagate their energy, the behavior of sound waves strongly depends on the mechanics of the materials they propagate through. In our experiment, we chose two materials which had different mechanical structure. One was a solid rod, and the other was a granular material, namely, sand. The sound waves which were used for this experiment had a frequency of 1 kHz to 1 MHz. This report consists of two parts. Part 1 discusses our findings when using solid rods, and Part 2 discusses the findings when using sand. | Hansen, Greg Hayashi, Miharu | Hansen, Greg | Hayashi, Miharu | 9371 | File Cabinet | 43.25 | ||||
| 1993-01-01 00:00:00 | Acoustic | Propagation of Waves Through Solid Rods at Audio Frequencies | By exciting thin, cylindrical rods of aluminum, titanium, acrylic, and birch wood with a nickel-core oscillator, we were able to produce longitudinal vibrations and find the resonant frequencies of the different rods. Our apparatus acts like a rod with one end clamped, having a node at the driving end. There was a definite linear relationship between the resonance frequencies and mode (or harmonic) number for each rod tested. We computed a X^2 value of 19.0 for the aluminum rod and 6.8 for the titanium rod in the graph of resonant frequencies vs. mode number. | Gates, Brian Johnson, Eric | Gates, Brian | Johnson, Eric | 9370 | File Cabinet | 43.25 | ||||
| 1993-01-01 00:00:00 | Misc | Rogue Waves - Water Wave Height Spectra | At sea, when the wind blows, the irregular surface it creates on the water is made up of a variety of waves moving in different directions, with different amplitudes, frequencies, and phases. I used a stationary pressure sensor suspended underwater to detect pressure changes due to the waves. I analyzed the data collected to determine the distribution of wave heights in order to determine the likelihood of large waves, that is, to determine the shape of the distribution of wave heights in order to project the likely shape of its large-wave tail. | Rubash, Lambert | Rubash, Lambert | 9395 | File Cabinet | ||||||
| 1993-01-01 00:00:00 | Optics | Examination of the Spectra of Everyday Light Sources | The spectrum of light from several sources was examined from 300 to 800 nm using an automated spectral monochrometer and a Motorola MRD5000 photo diode. The different spectra obtained and compared were from the sun, a Phillips 40 watt bulb, a Sylvannia 500 watt bulb, a GE 20 watt fluorescent light, a red LED, a yellow LED, and a mercury lamp. The spectrum of the sun was successfully modeled by a black body radiation curve, and the temperature was measured as 5800 K. A black body radiation curve for T=4200 K was the best fit for both 40 watt and 500 watt incandescent bulbs. | Johnson, Solveig K. Olson, Erik | Johnson, Solveig K. | Olson, Erik | 9351 | File Cabinet | |||||
| 1993-01-01 00:00:00 | Optics | Wavelength and Angle Dependence of Rayleigh Scattering | We tested the wavelength and angular dependence of Rayleigh scattering through a clear transparency sheet to experimentally confirm the predicted equations. We used violet, green, and yellow light from a mercury lamp as well as red light from a Helium-Neon laser and varied the measured angles from 0 to 170 degrees from that of the incident light. | Jansen, Chris Harte, Joe | Jansen, Chris | Harte, Joe | 9350 | File Cabinet | |||||
| 1993-01-01 00:00:00 | Condensed Matter Physics | Feasibility of Using New Liquid Xtal Materials in Thin Film Form | Five previously unstudied compounds were evaluated to determine whether or not they show an affinity for the thin film form. The transition temperatures of the compounds were determined by observing them under a microscope with a cross polarized light source. The thickness of the films was assessed by studying the light reflected off the film?s surface. Of the five compounds, two were shown to be good candidates for study in thin film form. | Johnson, Jesse | Johnson, Jesse | 9331 | File Cabinet | ||||||
| 1993-01-01 00:00:00 | Particle Experiments | Positron Annihilation Point Distribution of Ga in High Magnetic Field | The project was to determine the representative behavior of positrons in a high magnetic field. The experiment and detectors considered for the experiment are discussed. | Heil, Brian G. | Heil, Brian G. | 9322 | File Cabinet | ||||||
| 1993-01-01 00:00:00 | Particle Experiments | Level of Natural Gamma-Emitters in Common Substances | This project was intended to study the abundance of ?natural? Gamma-emitters, primarily Potassium-40, Thorium-232, and Uranium-238. This project is significant to any experimenters trying to study high-energy particles, because the procedure I used can be used to determine the radioactivity of the lab and therefore help in selection of materials and sites for the lab. | Thomas, James | Thomas, James | 9321 | File Cabinet | ||||||
| 1993-01-01 00:00:00 | Particle Experiments | Investigation of RN-222 Daughter Products in Rainwater | U-238, a naturally occurring radioactive isotope produces Rn-222 through its decay process. This radon gas, radioactive itself, the decays further in the air into Pb-214 and then Bi-214. By viewing the gamma rays given off by the rainwater with a germanium detector we can determine the presence of these daughter products. We can make a rough estimation of the amount of these isotopes present from the number of decays we detected. An attempt to determine the half-lives of these isotopes was unsuccessful. | Larsen, Thomas G. Rowley, Eric N. | Larsen, Thomas G. | Rowley, Eric N. | 9320 | File Cabinet | |||||
| 1993-01-01 00:00:00 | Condensed Matter Physics | Decay of Bit Transitions in Magnetic Media | 0 | Henrickson, | Henrickson, | 9332 | File Cabinet | ||||||
| 1992-01-01 00:00:00 | Misc | Tornado Simulation | It is difficult to obtain measurements with a tornado. This is due to the high winds associated with such a weather system. The use of dual Doppler radar has enabled us to see some air currents within a thunderstorm as it generates a tornado. Unfortunately, radar is only sensitive to water droplets and does not see air. The winds of a tornado are still unmeasured. Building and using a tornado simulator may give some insight into the mechanics and formation of actual tornadoes. | Leezer, | Leezer, | 9293 | File Cabinet | ||||||
| 1992-01-01 00:00:00 | Acoustic | Sound Attenuation | By studying a signal after traveling over some distance, and comparing it with the signal originally emitted, we should be able to analyze attenuation as functions of frequency, distance, and atmospheric conditions. | Kempe, Matthew Conley, Patrick | Kempe, Matthew | Conley, Patrick | 9270 | File Cabinet | 43.2 | ||||
| 1992-01-01 00:00:00 | Acoustic | Modeling Musical Sounds | Our project is concerned with analyzing musical sounds. The three determining characteristics of musical sounds are loudness, pitch, and tone quality or timbre. Loudness is merely the level of auditory sensation resulting from the incoming sound. Pitch is fundamentally connected with frequency of vibration, though other factors such as timbre may affect it slightly; therefore, pitch is, for the most part, independent of the instrument that produces the note. Tone quality is what allows the listener to distinguish between instruments playing the same note. Our project is to study both pitch and tone quality, with emphasis on the latter, to affirm and quantify existing theories about hem. One such theory is known as format theory, which will be discussed in the next section (Introduction text.) Fourier analysis, or more specifically, Fast Fourier Transformation (FFT), is the foundation of our investigation. Key to our analysis is the development of computer programs to make the similarities and differences between sound of instruments explicit. The goal is to gain an understanding of the physical and mathematical basis for music, and to get experience at using computers for analysis. | Braaten, Kristina Lin, Jin | Braaten, Kristina | Lin, Jin | 9271 | File Cabinet | 43.3 | ||||
| 1992-01-01 00:00:00 | Nonlinear Systems | Simulation of Percolation | The concept of percolation was first introduced by Broadbent and Hammersley. Today this problem is of major importance for the study of semiconductors. In this experiment the simulation of percolation was performed. The critical packing fraction was measured and the 1/f frequency of noise was observed. | Sinitsky, D. | Sinitsky, D. | 9280 | File Cabinet | ||||||
| 1992-01-01 00:00:00 | Misc | Electron Gun Design | An electron gun was designed and built. Three stainless steel cylindrical electrodes were built on an alumina ceramic frame. A tungsten filament was placed inside the first and shortest electrode; separate high voltage sources with negative polarity were used to charge the two longer electrodes. A high voltage current source powered both the first electrode and the filament. A phosphorus screen, placed approximately 0.5 inches from the end of the last electrode, was used to detect the electron beam, which was focused to a point approximately 1 mm in diameter. | Kopp, Kevin Fishpaw, John | Kopp, Kevin | Fishpaw, John | 9290 | File Cabinet | |||||
| 1992-01-01 00:00:00 | Misc | Exploration of Contaminants in the Atmosphere in Wind Cave | Air samples were taken in Wind Cave, South Dakota in an effort to determine if man made contamination was having any lasting effect, the samples were analyzed on quapropole mass spectrometer with a focus on finding hydrocarbons and determining if abnormal Carbon Dioxide levels existed. | Orrell, Roxana Schmid, Robert | Orrell, Roxana | Schmid, Robert | 9291 | File Cabinet | |||||
| 1992-01-01 00:00:00 | Misc | Determination of Asphalt Gasses in Jewel Cave | Asphalt pavements were laid in parts of Jewel cave of South Dakota over the last few decades. Over the years these pavements have released gases leaving a visible film on the limestone walls. We attempted to calculate the concentration of the asphalt gasses in the cave air and the rate at which these gasses were accumulating on the limestone walls using a mass spectrometer. | Ritchie, Kent | Ritchie, Kent | 9292 | File Cabinet | ||||||
| 1992-01-01 00:00:00 | Optics | Looking at Small Scale Images | Resolution of small images is limited by various factors, such as, the aperture of the sensing device, the diffraction caused by the aperture, and the focusing characteristics. This project investigates these properties and tries to determine a minimum resolving power. | Walsh, Mike Anderson, | Walsh, Mike | Anderson, | 9252 | File Cabinet | |||||
| 1992-01-01 00:00:00 | Misc | Measurement and Interpretation of Electrostatic Potential Gradient | By using a device to measure electric fields (a field mill) the atmospheric electrostatic gradient at the Earth?s surface was measured on fair weather days, and the results compared to conditions in the atmosphere. It was found that the electrostatic potential gradient varies with the time of day, due to the amount of pollution in the atmosphere. It was also found that the potential gradient increased by two orders of magnitude when a thundercloud was present, giving the field mill applications as a lightning predictor. | Hager, James R. Burmeister, Robert A. | Hager, James R. | Burmeister, Robert A. | 9295 | File Cabinet | |||||
| 1992-01-01 00:00:00 | Misc | Electronic Cavendish Device | The ?Electronic Cavendish Device? is a most promising method of determination of the universal gravitational force constant, G, in short time periods. Over time the torsion pendulum has been improved to the design presented here. The torsion bar will be damped by the electromagnetic interaction of a servo coil and a magnet. The torque on the bar due to the introduction of two external masses will be proportional to the change in voltage across the servo coil. This method is improvement over that of previous ones in that it makes the torque measurement incredibly easier and can yield a value in a matter of minutes. | Olson, Jeff Dorsey, Edward C. | Olson, Jeff | Dorsey, Edward C. | 9294 | File Cabinet | |||||
| 1992-01-01 00:00:00 | Misc | Shklovskii Effect | The purpose of this experiment is to investigate the repulsive force due to the surface charge distribution on two parallel conductor wires carrying a steady current in the same direction (beside the attractive magnetic force). In particular I use a thin tungsten wire because this effect has a resistance dependence. In my experiment, the method used is similar to Young Double Slit experiment to detect the displacement of the wires from its interference pattern. | Suriono, Usman | Suriono, Usman | 9296 | File Cabinet | ||||||
| 1992-01-01 00:00:00 | Optics | Goniophotometry/Measurement of Reflectance of Light at all Angles | In the printer industry, many different types of papers and films with various textures are used. This paper studies the behavior of light scattered by different surfaces. The reflection of light off of these surfaces will be measured to determine if there are any unusual effects of the scattering due to the angle of incidence and reflection, and if there are any effects due to polarization. | Kopp, Scott | Kopp, Scott | 9251 | File Cabinet | ||||||
| 1992-01-01 00:00:00 | Cosmic Ray Experiments | Cherenkov Telescope | When high energy charged particles traverse a medium with a velocity greater than the speed of light in that medium, a phenomenon known as Cherenkov radiation occurs. Much like the wake from a boat, an electromagnetic wavefront is produced. Charged particles in the vicinity of the wavefront are accelerated and thus radiate light. In our experiment we detected Cherenkov radiation resulting from cosmic rays entering the earth?s atmosphere. | Higgins, Michael Waters, Andrew | Higgins, Michael | Waters, Andrew | 9210 | File Cabinet | |||||
| 1992-01-01 00:00:00 | Particle Experiments | Electron - Positron Pair Production | One of the most interesting examples of conversion of radiant energy into rest mass energy is the process of pair production and annihilation. The Co6(0) radioactive source? may be used to create such an electron-positron pair. With sodium iodide as the detecting device, we verify such pair production and annihilation processes, and calculate the cross-section of such production in different materials (Pb, Cu, Al, etc.) | Lai, Jimmy Nelson, Eric | Lai, Jimmy | Nelson, Eric | 9220 | File Cabinet | |||||
| 1992-01-01 00:00:00 | Condensed Matter Physics | Building of Variable Temperature Hall System | This variable temperature hall system will measure the resistivity, carrier concentration, and mobility as a function of temperature indoped germanium silicon (GeSi) pseudomorphic layers on a silicon substrate from 77K to room temperature. | Tong, To | Tong, To | 9230 | File Cabinet | ||||||
| 1992-01-01 00:00:00 | Condensed Matter Physics | Thickness Dependence of Smectic C/I Transition Temp. for Liqu. Xtal 8Si | Using depolarized laser microscopy I planned to measure the smectic C-smectic I transition temperature by examining the changes in appearance of the domains when in different phases. Then, measuring the light intensity of a laser beam reflected off of the film, I would be able to determine the thickness of the sample. Therefore, I then could determine whether 8SI?s C-I transition was dependent upon the thickness of the sample. | Huber, William H. | Huber, William H. | 9231 | File Cabinet | ||||||
| 1992-01-01 00:00:00 | Condensed Matter Physics | Cooling Rate Dependence of the Glass Transition in Hydrogenated Amorphous Silicon | It has been proposed that the motion of hydrogen in hydrogenated amorphous silicon (a-Si:H) is responsible for the glass-like behavior of the electronic properties of a-Si:H. The electronic dark conductivity of n-type a-Si:H were studied as a function of cooling rate following a high temperature anneal. The fictive temperature, a property of the glass transition, for a-Si:H samples with different thickness? was measured. | Nichols, Jim Wynveen, Aaron | Nichols, Jim | Wynveen, Aaron | 9232 | File Cabinet | |||||
| 1992-01-01 00:00:00 | Atomic Physics | Electron Spin Resonance | When unpaired electrons are placed in a magnetic field they tend to align their spin moments with or against the direction of the field. These two alignments have different energies and the relative populations in equilibrium are given by the Boltzmann distribution. By exposing these electrons to microwave radiation corresponding to the energy splitting, resonance can be observed. We set out to observe the phenomenon of electron spin resonance in order to measure Lande g factors of various materials and magnetic field strengths with high precision. | Cassola, Steve Ruzek, Dan | Cassola, Steve | Ruzek, Dan | 9240 | File Cabinet | |||||
| 1992-01-01 00:00:00 | Optics | Measurement of the Optical Rotatory Dispersion of Solutions | We measure the specific rotation of fructose, ascorbic acid, and menthol as a function of wavelength. The results are in excellent qualitative agreement with the theoretical model of Drude and quantitative agreement with the measurements of Lowry. We use the Drude equation to calculate the wavelength of absorption of the principal chromophore in fructose. | Roban, Philip K. McCollam, Karsten | Roban, Philip K. | McCollam, Karsten | 9250 | File Cabinet | |||||
| 1991-01-01 00:00:00 | Atomic Physics | Zeeman Effect in Mercury | The intent of this experiment is two-fold. First, observation of the Zeeman effect in Mercury, which will require comparison between atoms subjected to a magnetic field to those which are not. Secondly, to acquire and analyze data which will allow us to predict the energy levels of the atoms and also to show the inconsistency in the classical theory predicted by Lorentz. | Hausken, Greg Radosevich, Pete | Hausken, Greg | Radosevich, Pete | 9140 | File Cabinet | |||||
| 1991-01-01 00:00:00 | Misc | Gas Analysis Using Mass Spectrometry | The Vacscan Plus Residual Gas Analyzer, which contains a quadrupole mass spectrometer, is used to study the molecular composition of gas samples. The sensitivity of the instrument is determined through the analysis of known, and well behaved samples. | Bailey, John Hagg, Jessica | Bailey, John | Hagg, Jessica | 9192 | File Cabinet | |||||
| 1991-01-01 00:00:00 | Misc | Impurities in Proportional Tubes | Proportional tubes measure the ionization rate of a gas or mixture of gases given some source of ionization. A high voltage anode runs the length of the tube, and free electrons from ions collect along it, producing a measurable current (called dose rate). The dose rate can be dramatically affected, however, by impurities (?poisons?) within the tube. It is our purpose to measure the effect of such poisons using two proportional tubes?one control and one experimental?for various sources and quantities of impurity. | Siewerdsen, Jeff Ryden, David | Siewerdsen, Jeff | Ryden, David | 9191 | File Cabinet | |||||
| 1991-01-01 00:00:00 | Misc | Measuring Ionization Energies with a Cylindrical Ionization Gauge | A modification of a high pressure cylindrical ionization gauge should allow me to measure the ionization potentials of gases more accurately through increased electron and ion gathering efficiency. The modified grid consists of a tungsten filament which in encircled by a grid and a cylindrical can with lids on the top and bottom. By varying the voltages on the grid, the can, and the lids, I should be able to determine which combination will yield the best electric potential field configuration for determining ionization voltages. | Lai, Sonia | Lai, Sonia | 9190 | File Cabinet | ||||||
| 1991-01-01 00:00:00 | BioPhysics | Galvanic Skin Response | When exposed to a stimulus, one becomes nervous and the palms of one's hands begin to sweat. This phenomenon was noticed, and the hypothesis came into existence that the reduction of skin resistance associated with a stimulus is caused by the secretion of sweat due to the activated sweat glands that are controlled by the automatic nervous system. In this study, the morphology of the skin will be discussed followed by a model explaining the electrodermal properties. One of these properties, the skin resistance, will be examined and a circuit developed to measure this property. Finally, a procedure for acquiring results as well as an analysis of the measured data will be presented. | Zuzak, Karel | Zuzak, Karel | 9161 | File Cabinet | ||||||
| 1991-01-01 00:00:00 | BioPhysics | Gravitational Effects on Arterial Blood Pulse Speed | Noninvasive diagnostic methods are needed to study changes in physiological parameters in humans... The physiological parameter of interest was the blood pulse speed in the radial artery, located in the forearm. The pulse was viewed at two positions on the forearm separated by a distance of 4 cm. By viewing the two signals simultaneously, information could be gained on the blood pulse speed and other hydrodynamic (blood motion) properties. | Meadows, | Meadows, | 9160 | File Cabinet | ||||||
| 1991-01-01 00:00:00 | Optics | Infrared Spectrophotometry of in Situ Reaction Products from a Solar Furnace | An infrared spectrophotometer was constructed to determine the gas composition in sealed quartz vessels. These vessels contain the reaction products from a water-coal mixture, exposed in a solar furnace. A quartz optics monochrometer was modified with a pyroelectric detector and infrared source to measure the infrared absorption of CO, CO2, and CH4, in the double transition 1.7 to 2.5 micrometer region of the spectra. The transmission of the quartz in the reaction vessel limited the spectral range of the spectrophotometer, allowing only two level vibrational transitions to be observed. | Bernstein, Kenneth Thayer, Darryl | Bernstein, Kenneth | Thayer, Darryl | 9152 | File Cabinet | |||||
| 1991-01-01 00:00:00 | Optics | Construction and Investigation of a Nitrogen Laser | Construction of a simple, high-power nitrogen laser and measurement of its wavelength and power as a function of pressure is presented. | Olson, Eric Worner, Paul | Olson, Eric | Worner, Paul | 9150 | File Cabinet | |||||
| 1991-01-01 00:00:00 | Condensed Matter Physics | Mesoscopic Structures and the Observation of the Aharanov-Bohm Effect | The Aharonov-Bohm effect has revealed the physical existence of the electromagnetic scaler and vector potentials. Investigation of the solid state Aharonov-Bohm effect was attempted using mesoscopic structures fabricated using electron beam lithography. Although mesoscopic structures are composed of a large number of particles, they exhibit the quantum mechanical properties of microscopic systems. The proposed measurements were to observe the quantum conductance fluctuations caused by electron-wave interference in ultra-small (mesoscopic) loops of solid conductors. | Hadlich, Daniel | Hadlich, Daniel | 9132 | File Cabinet | ||||||
| 1991-01-01 00:00:00 | Condensed Matter Physics | Dynamic Response of Selected Magnetic Materials | Information about the dynamic response of a magnetic system can be obtained from studies of the frequency and temperature dependence of its magnetic susceptibility. This project focused on determining the response of commercially produced magnetic colloids, called ferrofluids , to an ac magnetic field through measurement of their susceptibilities. | Sigsbee, Kristine | Sigsbee, Kristine | 9131 | File Cabinet | ||||||
| 1991-01-01 00:00:00 | Condensed Matter Physics | EM Properties of Materials at Microwave Frequencies | Using interferometric methods inside rectangular X band microwave waveguides operating in TE10 mode, the real and imaginary components of the electric permittivity epsilon at 22 degrees Celsius for the dielectrics polytetrafluoroehtylene (Teflon) and soda-lime-silicate glass (Corning 0080) were measured. A comparison is made between these measurements and the accepted values, and the accuracy is discussed. | Kaufmann, Dan | Kaufmann, Dan | 9130 | File Cabinet | ||||||
| 1991-01-01 00:00:00 | Particle Experiments | Radon Measurement in Air | A device was built that was designed to make a direct, real time measurement of radon concentrations in air. It used a pair of photomultiplier tubes in conjunction with zinc sulfide screens to detect the alpha particle emitted during radon decay. | Olson, Andy | Olson, Andy | 9121 | File Cabinet | ||||||
| 1991-01-01 00:00:00 | Particle Experiments | Particle Attenuation in Matter | The interaction of particles with matter is studied by using different particle sources producing gammas and betas, penetrating various types of material. This will help in evaluating radiation protection for people working with radioactive sources. | Wang, Roy | Wang, Roy | 9120 | File Cabinet | ||||||
| 1991-01-01 00:00:00 | Condensed Matter Physics | Resistivity Measurement of 3rd Sound in Superfluid He-4 | Third sound in superfluid liquid 4He was produced and measured using resistive techniques. This aluminum films were evaporated onto a glass slide in the form of strips 20 mils wide and .75? long. The films varied in thickness from about a hundred angstroms to several hundred angstroms. The thickest film was used as a heater to excite third sound oscillations. The thinnest strip was used as a bolometer to detect the temperature variations associated with the third sound. The bolometer strip was operated near its superconducting transition temperature, so that its resistance was a strong function of temperature. | Braaten, Karsten | Braaten, Karsten | 9133 | File Cabinet | ||||||
| 1991-01-01 00:00:00 | Optics | Linearity of a Laser Imager | In certain laser imaging techniques it is important to know how linear the position of a laser beam is with respect to time as the beam is swept across a flat plate. This project's purpose was to design a technique for measuring the linearity of this sweep. A basic imager was constructed and a technique employing a Ronchi ruling and photomultiplier tube was used to collect data which would allow a position vs. time graph to be plotted. This data could then be fit to a known function. Programs were written to generate a position vs. time graph and to fit this graph to a polynomial or a straight line. The position with respect to time did appear to be fairly linear although deviations corresponding to the expected tangential relationship between position and time were observed. | Schelling, Reich, Doug | Schelling, | Reich, Doug | 9151 | File Cabinet | |||||
| 1991-01-01 00:00:00 | Misc | Measurement of Relativistic Time-of-Flight of Electrons | At high velocities, the classical relationship between energy and velocity fails. In this experiment, we analyze this phenomenon by giving a large energy to electrons, then measuring the time it takes the electrons to travel a known distance. With this information, we can calculate deviations from classical theory and compare our experimental values with relativistically predicted values. | Dwinnell, Heidi Reuteler, Dave | Dwinnell, Heidi | Reuteler, Dave | 9193 | File Cabinet | |||||
| 1990-01-01 00:00:00 | Condensed Matter Physics | Fabrication and Analysis of the High Tc Compound YBaCuO | Report Missing. | McDonald, Michael Waters, Daniel | McDonald, Michael | Waters, Daniel | 9034 | File Cabinet | |||||
| 1990-01-01 00:00:00 | Misc | Local Oscillator for a Radio Telescope | During the past ten weeks, we have constructed a local oscillator system for a radio telescope receiver. Stability problems encountered in the past have been eliminated through isolation of the oscillator and construction of a stable power source. We reduced the frequency fluctuation to 5 kHz when operating at 1.35 GHz. The result is a stable, low noise oscillator. These improvements will allow accurate collection of data from the radio telescope. | Baumgardt, Katherine Durkee, Russ | Baumgardt, Katherine | Durkee, Russ | 9091 | File Cabinet | |||||
| 1990-01-01 00:00:00 | Condensed Matter Physics | Measuring Tc for Bulk Sample Supercond. Using Magnetic Susceptibility | A simple A.C. Susceptometer is used to measure Chi(T,omega) for 4K<T<300K at frequencies 100hz<omega<10khz. Materials to be observed include paramagnets, dimagnets (superconductors), ferromagnets, and antiferromagnets. | Berg, Mark | Berg, Mark | 9033 | File Cabinet | ||||||
| 1990-01-01 00:00:00 | Misc | High Resolution Atmospheric Pressure Measurement | Two high-resolution pressure sensors from Motorola were interfaced to a computer to determine the accuracy and sensitivity of the sensors with respect to a calibrated mercury barometer. In the meantime, the sensors were used to detect interesting atmospheric phenomena such as buoyancy waves and thunderstorms. | Helmberger, Zac | Helmberger, Zac | 9092 | File Cabinet | ||||||
| 1990-01-01 00:00:00 | Misc | Io Related Decameter Radiation from Jupiter | We investigated the flux, the characteristic audio noises, and the predictability of Io related decameter radiation from Jupiter. We centered our observations at 28 megahertz. We used a short-wave radio receiver and a full wavelength antenna. We expected typical bursts on the order of 10^5 W/m^2/Hz (3) in flux units and measured a probable burst between 4*10^5 and 2*10^ W/m^2/Hz in flux units. We were unable to identify the characteristic audio noises of the signal. And, by using a computer simulation, we were able to predict the probable burst to within three hours. Information about radiation in the 28 megahertz range from the sun is also included. | Johnson, Scott Cava, Dave | Johnson, Scott | Cava, Dave | 9090 | File Cabinet | |||||
| 1990-01-01 00:00:00 | Nonlinear Systems | Chaotic Behavior in a Dripping Faucet | The dripping faucet is a simple system which was used to analyze chaos. Oscillations due to surface tension of the water drops make the system nonlinear and give rise to chaotic effects, such as period doubling and aperiodicity. Data was taken consisting of time intervals between drops with photodiodes and an IBM PC. Programs constructed return maps in two and three dimensions from data. This experiment explored chaotic regions of flow rates of the faucet with the result that new information about the dripping faucet emerged beyond that of the previous experiment of Shaw (1984). | Gaard, Peter Schmidt, Jacob | Gaard, Peter | Schmidt, Jacob | 9080 | File Cabinet | |||||
| 1990-01-01 00:00:00 | Optics | Character Recognition | We have developed an efficient procedure for recognizing type-written characters based on previous work in character recognition and our own theoretical background. The procedure consists of digitizing an analog image, transforming the image with the Fourier Transform (1), the cross-correlating (2) two transformed images. The cross-correlation, a Fourier Optical process that we have introduced to the study of character recognition, determines a degree of similarity between the two test images. The degree of similarity is used to determine the identity of the character. | Mack, Andrew P. Radman, Bill O. | Mack, Andrew P. | Radman, Bill O. | 9050 | File Cabinet | |||||
| 1990-01-01 00:00:00 | Condensed Matter Physics | Second Sound in Liquid Helium | This experiment was designed to measure the velocity of second sound in superfluid liquid helium. The apparatus, based on a time-of-flight method and a carbon film detector, failed to detect second sound. | Siskind, Lisa Hart, Douglas | Siskind, Lisa | Hart, Douglas | 9031 | Not Yet Filed | |||||
| 1990-01-01 00:00:00 | Condensed Matter Physics | Measurement of 2nd Sound as a Function of Temperature in Superfluid He | This report describes an experiment involving the detection and recording of thermal waves in liquid He4. These waves, known as second sound, were detected in a resonating chamber electronically. The waves were observed for various temperatures to verify the theoretical predictions of the two fluid model of helium. | Costello, Robert Perttula, Melissa | Costello, Robert | Perttula, Melissa | 9030 | Not Yet Filed | |||||
| 1990-01-01 00:00:00 | Particle Experiments | Radon Emission From Soil Samples Using Zinc Sulfide Screen & PM Tube | Our project is measuring the amount of radon emitted from various soil samples. We built, calibrated and tested an alpha particle detector for measuring the amount of radon coming from the soils. We found that certain soils such as gravel and dirt have a significantly greater amount of radon emanation that potting soil and building materials. | Abney, Faith E. Johnson, Mike | Abney, Faith E. | Johnson, Mike | 9020 | Not Yet Filed | |||||
| 1990-01-01 00:00:00 | Cosmic Ray Experiments | The Magnetic Moment of Free Muons | The experiment stems from the non-conservation of parity in the decay chain (pi)(mu)(e-). Muons polarized from the decay process are stopped in an aluminum target and allowed to precess in a known magnetic field. As the spin of the muons precess, they decay into a positron and two neutrinos. The angular distribution of positrons will be taken and graphed as a function of time. This time is the precession frequency, which can be used to derive the magnetic moment of the muon. | Roen, Mike Smith, Matt Baker, Dan | Roen, Mike | Smith, Matt | Baker, Dan | 9010 | Not Yet Filed | ||||
| 1990-01-01 00:00:00 | Atomic Physics | Verification of the Zeeman Effect in Mercury Vapor | Quantum theory predicts the existence of the splitting of the spectral lines of elements when they are placed in a magnetic field: This is called the Zeeman effect. By use of a high resolution Fabry Perot interferometer this project verified the existence of the Zeeman effect and demonstrated reasonable agreement with theoretical predictions. | Kunz, Conrad | Kunz, Conrad | 9040 | File Cabinet | ||||||
| 1990-01-01 00:00:00 | Condensed Matter Physics | EM Properties of Materials at Microwave Frequencies | Imperfect dielectric materials exhibit energy loss due to internal mechanisms. One often characterizes the loss parameters by including them in the electric permittivity as a complex component. Similarly, one can observe loss due to magnetic dissipation by a material and the corresponding complex magnetic permeability. We have measured the complex permittivity and permeability of Cd(1-x)Mn(x)Te crystals, a magnetic semiconducting material, by implementing a microwave resonance system. | Truscott, Anthony D. | Truscott, Anthony D. | 9032 | Not Yet Filed | ||||||
| 1990-01-01 00:00:00 | Atomic Physics | Production and Detection of Metastable Helium | A beam of He atom is driven into the metastable 2S state by bombardment from 20 eV electrons and detected as they fall on a metal surface where they eject electrons. | Wilson, Kipp Logajan, James | Wilson, Kipp | Logajan, James | 9041 | File Cabinet | |||||
| 1990-01-01 00:00:00 | Condensed Matter Physics | Ferroelectric Properties of Barium Titanate | Dolezal, Michael | Dolezal, Michael | 9038 | File Cabinet | |||||||
| 1989-01-01 00:00:00 | Cosmic Ray Experiments | Detection of Muons From the Direction of Cygnus X-3 | We have attempted to confirm previous claims of a cosmic ray signal initiated by Cygnus X-3. This was done by monitoring the muon flux from the direction of Cygnus X-3 with an above ground muon telescope, as opposed to the deep underground particle detectors used before. No conclusive evidence of a signal was found. | Everitt, Brenda Jones, Ann | Everitt, Brenda | Jones, Ann | 8910 | Not Yet Filed | |||||
| 1989-01-01 00:00:00 | Condensed Matter Physics | Computer Interface with X-Ray Diffractometer | The motivation for this project was to interface the IBM PC computer with the X-Ray Diffractometer equipment so as to be able to perform an X-Ray diffraction experiment. X-Ray Diffraction is a fascinating subject whereby one is able to actually get a picture of the interatomic spacings and structure of crystals. | Hoskin, Janet Kwilinski, Mike | Hoskin, Janet | Kwilinski, Mike | 8930 | Not Yet Filed | |||||
| 1989-01-01 00:00:00 | Acoustic | Active Noise Control | (Note from editor: Very long intro . . .) Keyword list: Superposition, Feedback, low-frequency, noise reduction, active noise control, anti-noise. | Hupalo, Peter Landgraf, Jeff | Hupalo, Peter | Landgraf, Jeff | 8970 | File Cabinet | 43.5 | ||||
| 1989-01-01 00:00:00 | BioPhysics | Compensating Helmholtz Coils as a Magnetocardiogram | In our experiment, we attempted to detect the faintly changing magnetic fields from the heart, which are on the order of 10^-13 tessla. To accomplish this, we needed adequate shielding as well as a sensitive pick-up. In a recent article by Edward M. Purcell, it was suggested that a set of compensating Helmholtz coils may achieve both without need for further exterior shields to block ambient magnetic fields. | Kim, Michael H. Wilson, Alex | Kim, Michael H. | Wilson, Alex | 8960 | Not Yet Filed | |||||
| 1989-01-01 00:00:00 | Optics | Measuring Curvature of a Surface Using Electronic Speckle Pattern Interferometry | Surface finishing of materials using diamond grinding result in residual compressive surface stresses. The primary origin of these stresses is plastic deformation of the surface due to the indenting action of the grinding abrasive. Residual surface stress can be calculated using an equation which relates curvature to surface stress. Typically curvature measurements have been made using profilometers with a diamond stylus. The surface stresses can then be characterized (either tensil or compressive) by masking one surface, measuring the curvature of the machined surface, etching the machined surface, and repeating until the stresses have been characterized. If these measurements can be made by a mechanical technique, then for small deformations, the curvature can also be measured optically. We attempted to use Electronic Speckle Pattern Interferometry (EPSI) to measure curvature. | Knight, Ray Friebe, Mike | Knight, Ray | Friebe, Mike | 8951 | Not Yet Filed | |||||
| 1989-01-01 00:00:00 | Condensed Matter Physics | High Temperature Superconductivity | The purpose of our experiment was to manufacture a YBa2Cu3O7-X ceramic substance with a known superconducting critical temperature above 77K and determine the effects of a magnetic field on its critical temperature. The tests first measured resistivity versus temperature without a magnetic field and then were repeated with different magnetic fields. | Shahin, Mahmoud Shakouri, Hooman Wire, Jim | Shahin, Mahmoud | Shakouri, Hooman | Wire, Jim | 8931 | Not Yet Filed | ||||
| 1989-01-01 00:00:00 | Cosmic Ray Experiments | Measure of Decoherence Curve and Average Size of Cosmic Ray Air Showers | The phenomenon of Cosmic Ray Air Showers has been investigated by physicist for over half a century. One interesting property of an air shower is its average size. Our experiment proposes to determine the average size of the core of cosmic air showers. By employing two detectors and some logic circuits to determine coincidence between detectors, a plot of coincidence rate vs. the detectors separation can be constructed. The result of this plot is a smooth curve known as a Decoherence Curve. From this, we can determine the average size of the core of the air shower. | Nelson, Steve Scully, Sean Thomas | Nelson, Steve | Scully, Sean Thomas | 8914 | Not Yet Filed | |||||
| 1989-01-01 00:00:00 | Cosmic Ray Experiments | Study of Time Dilation of Cosmic Ray Muons and Measure of Mean Lifetime. | The purpose of our experiment is to study the effect of time dilation on cosmic ray muons. The muons being studied have been formed by collisions between high-energy pions produced outside the Earth's atmosphere and atomic nuclei of various components of the atmosphere. A pion, which has either a positive or negative charge, decays into a positively or negatively charged muon and a neutrino. The muon will continue to travel towards the Earth's surface, losing energy through collisions or ionization of electrons. Eventually these muons will decay into an electron or positron (depending on the charge of the muon) and two neutrinos. The electron ionizes other particles in the atmosphere and can be detected to determine the approximate decay time of the muon. | Connelly, Brian Lind, Richard Gabbard, Steve | Connelly, Brian | Lind, Richard | Gabbard, Steve | 8913 | Not Yet Filed | ||||
| 1989-01-01 00:00:00 | Cosmic Ray Experiments | Detection of Cherenkov Radiation from High Energy Cosmic Rays | A Cherenkov radiation detector was designed and built to use three photomultiplier tubes in coincidence and one scintillation counter as a trigger. This apparatus was used to detect the light pulses of Cherenkov Radiation produced in the atmosphere from high energy cosmic rays. Using a coincidence/veto circuit and shielding away as much background light as possible, we were able to detect light pulses in coincidence with cosmic ray particles. By keeping the sensitivity low on the detectors we could concentrate on only the highest energy cosmic ray particles; the ones that produce light pulses intense enough for our equipment to detect. | Mitchell, Jim Zurn, Robert Brown, Scott | Mitchell, Jim | Zurn, Robert | Brown, Scott | 8911 | Not Yet Filed | ||||
| 1989-01-01 00:00:00 | Cosmic Ray Experiments | Detection and Determination of the Muon Magnetic Moment | Maximal parity violation in the pion decay leads directly to entire and absolute muon polarization. Subsequent parity violations in the muon decay set up an asymmetrical positron emission distribution (measured relative to the muons spin). The muons magnetic moment precesses when placed in a magnetic field and so also does the asymmetrical positron distribution. By detecting outgoing positrons over a certain solid angle a decay a decay curve with a sinusoidal perturbation can be obtained. The frequency of this perturbation is proportional to the muons moment strength and, therefore, by experimentally measuring this frequency conclusions can be made about the muons magnetic moment. | Brown, Scott Lamecker, Jim Walsh, Mike | Brown, Scott | Lamecker, Jim | Walsh, Mike | 8912 | Not Yet Filed | ||||
| 1989-01-01 00:00:00 | Atomic Physics | The Production and Detection of Metastable Atomic Hydrogen | Our goal was to duplicate, in part, the work of Lamb and Retherford (late 1940's and early 1950's). We centered our attention on the production and detection of metastable atomic hydrogen. We essentially followed methods employed by Lamb and Retherford. Our project consisted of four basic components: the thermal dissociation of molecular hydrogen into atomic form, excitation of the hydrogen atoms to the metastable state via electron bombardment, DC quenching of the metastable atoms in an applied electric field, and detection of the metastable atoms by electron ejection from a metal surface. | Mergen, John C. Villaume, Garrick M. | Mergen, John C. | Villaume, Garrick M. | 8940 | File Cabinet | |||||
| 1988-03-01 00:00:00 | Optics | Holographic Deformation Analysis | Using double exposure holography ( using a 6mW He/Ne laser) we measured the displacement of a 3/4" x 3/4" x 8" bar of aluminum under stress. The results we obtained were within 3.7% of the theoretical expectation. | Bauer, Kirby Kleist, David | Bauer, Kirby | Kleist, David | 8854 | Not Yet Filed | |||||
| 1988-01-01 00:00:00 | Atomic Physics | Nuclear Magnetic Resonance | In this experiment we have induced and detected nuclear magnetic resonance of protons in water. From the results, we were able to determine the proton's Gyromagnetic ratio and its g factor. | Beltran, Emilio Lopez Gorbatenko, Kristina | Beltran, Emilio Lopez | Gorbatenko, Kristina | 8840 | File Cabinet | |||||
| 1988-01-01 00:00:00 | Condensed Matter Physics | Quantitative Analysis of Powder Diffraction | This project dealt with the usage of the X-ray Powder Diffraction technique to quantitatively analyze the concentrations of two-component mixtures. Results obtained lacked desired precesion, but through this project, a clear understanding of problems of the X-ray Powder Diffraction techniques was gained. | Kim, Daniel J. | Kim, Daniel J. | 8833 | Not Yet Filed | ||||||
| 1988-01-01 00:00:00 | Condensed Matter Physics | Critical Magnetic Field vs. Temperature in a Superconducting Thin Film of Tin | In this experiment we measured the dependence of superconductivity upon an applied magnetic field. We first created a thin film of Tin by vacuum evaporation. The sample was then cooled in the absence of a magnetic field to determine its superconduction critical temperature via a standard four lead method. | Dachelet, Bill Nelson, Craig | Dachelet, Bill | Nelson, Craig | 8832 | Not Yet Filed | |||||
| 1988-01-01 00:00:00 | Condensed Matter Physics | Fabrication of Free-Standing Thin Films | Free standing titanium films 100 nm thick are being constructed. The titanium films are created by vacuum evaporation on a copper foil substrate, which must first be rid of any surface defects. A free-standing region of titanium 30 microns in diameter is then made by removing a portion of the copper foil using photolithography to prepare a mask for a wet chemical etch. The photoresist is removed using an oxygen plasma etch. | Karels, Eugene | Karels, Eugene | 8831 | Not Yet Filed | ||||||
| 1988-01-01 00:00:00 | Condensed Matter Physics | Automated Annealing Process for the Synthesis of Superconducting Materials | The synthesis of the current high temperature superconducting compounds requires a long term annealing process (12 or more hours). The annealing process involves a baking of the sample with a high temperature oven in elevated oxygen conditions. We have developed a system which automates this process, thereby allowing greater accuracy and eliminating the need for manual control over the period of several hours. | Hamilton, Guy Ewing, Paul | Hamilton, Guy | Ewing, Paul | 8830 | Not Yet Filed | |||||
| 1988-01-01 00:00:00 | Particle Experiments | SSD's at the SSC (Radiation Damage) | In the following discussion I address the operating characteristics of silicon strip detectors and the effects and mechanisms of radiation damage. I then extrapolate these results to the SSC environment. I have also included a brief summary of hydrogen amorphous silicon (a-Si:H) and discuss its characteristics in the SSC environment also. | Henderson, Michael R. | Henderson, Michael R. | 8820 | Not Yet Filed | ||||||
| 1988-01-01 00:00:00 | Cosmic Ray Experiments | Detection of Cherenkov Light From Extensive Cosmic Ray Air Showers | When a charged particle travels faster than the velocity of electromagnetic radiation in a given medium, it emits a burst of blue light known as Cherenkov radiation. One natural source of Cherenkov radiation is highly energetic cosmic ray electrons. . . We were able to discriminate 30 mV-50 mV signals against a background of 10 mV using an array of three photomultiplier tubes. | Edlund, Greg Horrisberger, Tom | Edlund, Greg | Horrisberger, Tom | 8810 | Not Yet Filed | |||||
| 1988-01-01 00:00:00 | Atomic Physics | A Recreation of the Franck-Hertz Experiment Using Computer Data Collection & Analysis | The purpose of this experiment was to reproduce the 1914 experiments of Franck and Hertz using a microcomputer to control the experiment. | Susag, John R | Susag, John R | 8841 | Not Yet Filed | ||||||
| 1988-01-01 00:00:00 | Optics | Michelson Interferometer Spectroscopy with FFT | This is an experimental spectroscopy project involving the design and construction of a computer controlled Michelson Interferometer. The device is used to find the spectral distribution curves of various light sources including that of a HeNe Laser, and the emission spectra of sodium, thallium, mercury, and cadmium. This project is designed to explore the details of Michaelson Interferometer Spectroscopy with the mathimatical methods of Fast Fourier Transforms. | Johnson, Jeffery L. Freidrich, Mitch | Johnson, Jeffery L. | Freidrich, Mitch | 8850 | Not Yet Filed | |||||
| 1988-01-01 00:00:00 | Acoustic | Transmission of Sound as a Function of Humidity at 26 C | The purpose of this experiment was to make measurements to determine the effects of humidity on the attenuation of sound in air at different frequencies. All of the measurements were taken at 26 C. A 30' tube system was used with a speaker and microphone at either end to observe the sound transmission. This system allows for a high frequency resolution not achieved in previous experiments. We found that adding water vapor to air indeed changes the attenuation, but that resonances in the system affected the quality of the data, | Pfund, John Osterlund, Philip | Pfund, John | Osterlund, Philip | 8870 | Not Yet Filed | 43.28 | ||||
| 1988-01-01 00:00:00 | Misc | 1420 MHz Heterodyne Radio Telescope | This quarter we followed up on previous groups work on the radio telescope. The majority of our work consisted of running tests on the efficiency of different combinations of equipment for the front end electronics. We also used the sun as a 1420 MHz source to determine system temperature and antenna efficiency. | White, Kevin Norton, Eric | White, Kevin | Norton, Eric | 8892 | Not Yet Filed | |||||
| 1988-01-01 00:00:00 | Misc | On-line Process Monitoring of Corona Discharges | Process monitoring of the various parameters involved in corona treatment of polymer films is valuable both as a fundamental tool to understand the mechanisms involved, but also to insure consistent quality when placed on-line in production. This report details the steps taken to interface comercially available sensors and data acquisition devices with a custom built corona treater under computer control. The data gathered in the experiments will be used to refine the corona equipment and gain experience in on-line process monitoring and control. | Morgen, Mark | Morgen, Mark | 8891 | Not Yet Filed | ||||||
| 1988-01-01 00:00:00 | Misc | Measuring the Depth of Glacial Till Using Seismic Techniques | The depth of the glacial till at a site in Cass County, Minnesota was measured using seismic refraction and reflection techniques. This depth was calculated to be approximately 24.8 meters or 81 feet. | Croswell, Daniel R. | Croswell, Daniel R. | 8890 | Not Yet Filed | ||||||
| 1988-01-01 00:00:00 | Optics | Spectrophotometer Automation | The purpose of this project was to automate the operation and data acquisition of a Beckman model DB grating spectrophotometer. This was done with the use of an IBM PC and supplemental hardware. This supplemental hardware is a separate unit and has its own power supply. The interface from the PC to this hardware is provided through the use of a parallel printer port. | Theobald, Ed | Theobald, Ed | 8851 | Not Yet Filed | ||||||
| 1988-01-01 00:00:00 | BioPhysics | Measurement of Radon Concentrations in Air by Detection of Radon Daughter Products | We have calculated the concentration of radon in the air using a silicon surface barrier detector linked to a multichannel analyzer to measure the decays of the daughter product RaA. A vacuum pump deposited the RaA on a filter positioned close to the surface of the detector. We have detected a concentration of 0.098 +/- 0.017 pCi/liter in a well-ventilated room over a 13 hour run time. | Odell, Eric Jones, Brian | Odell, Eric | Jones, Brian | 8860 | Not Yet Filed | |||||
| 1988-01-01 00:00:00 | Optics | Study of Brownian Motion by Laser Scattering | Brownian motion is defined as the random thermal motion of small particles suspended in a liquid. This motion can be quantitatively studied by analyzing light scattered from the suspended particles. The light from a laser scattered through a suspension was studied during this project. The monochromatic light changes frequency slightly when it is scattered. These changes were measured and from these measurements the diffusion constant was determined. | Blair, Alan | Blair, Alan | 8853 | Not Yet Filed | ||||||
| 1988-01-01 00:00:00 | Optics | Object Deformation Measurement with Electronic Speckle Interferometry | Electronic speckle pattern interferometry, specifically speckle pattern correlation interferometry, is used to measure deformation of objects with optically rough surfaces. The speckle interferogram of a this aluminum beam is generated arithmetically from two stored digitized images of speckle patterns before and after the beam deflection. The objective of the experiment is to show that low cost computer image processing equipment can be used for accurate deformation analysis. | Hupfer, Werner | Hupfer, Werner | 8852 | Not Yet Filed | ||||||
| 1988-01-01 00:00:00 | Condensed Matter Physics | Fabrication of Yttrium Barium Copper Oxide and Lanthium Barium Copper Oxide High Temp. Semicondutors | This report describes the techniques attempted in the process of making Yba(2)Cu(3)O(7-x) and LaBa(2)Cu(3)O(9-x) superconductors and some of the problems that were encountered while trying to produce them. | Evans, Matthew Heinrich, Michael | Evans, Matthew | Heinrich, Michael | 8834 | Not Yet Filed | |||||
| 1988-01-01 00:00:00 | Nonlinear Systems | Detection of Chaos in a Mechanical Forced Pendulum | I have studied chaotic effects in an actual physical pendulum. I present observed chaotic and non-chaotic states as a function of driving frequency for two moment of inertia parameters of the pendulum. I display the results through Fourier transform power spectra, phase space diagrams, and signal versus time graphs. The system, although much less precise than previously studied electrical and numerical systems, displays similar results to those found by previous experimenters. | Amundson, James | Amundson, James | 8880 | Not Yet Filed | ||||||
| 1988-01-01 00:00:00 | Particle Experiments | Rutherford Scattering | The objective of our project is to experimentally verify the Rutherford model of the atom. We will do this by scattering a beam of alpha particles off a gold foil. The rate of the alpha particles we measure for our scattering angles (chosen at 30, 35, 40, 45, and 50 degrees) will then be compared to the predictions of the Rutherford model. | Mueller, Byron Samsel, Peter | Mueller, Byron | Samsel, Peter | 8821 | File Cabinet | |||||
| 1987-01-01 00:00:00 | Misc | 1420 MHz Superhetrodyne Radio Telescope | A 1420 MHz superhetrodyne radio spectrometer was assembled, and all the components were tested. Frequency, noise, gain, and power characteristics were determined for the components individually. An over-all system temperature was determined, as well as a limiting sensitivity. | Murray, Margaret Smith, Toby | Murray, Margaret | Smith, Toby | 879x | Blue Binders General Physics 2 | |||||
| 1987-01-01 00:00:00 | Optics | The Completion of a Mode-Locked CW Dye Laser and CW Autocorrelator | A linear-cavity synchronously pumped hybrid mode-locked cw dye laser has been completed and a cw autocorrelator has been constructed. The general theory behind the operation of the dye laser and the autocorrelator is presented here along with relevant data that was obtained during the construction and testing. | DuBruil, Thomas P. Fotsch, Samuel | DuBruil, Thomas P. | Fotsch, Samuel | 875x | Blue Binders Optics 3 | |||||
| 1987-01-01 00:00:00 | Optics | Brownian Fluctuations by Laser Scattering | When light is scattered from a cell containing a suspension of particles in a fluid, we can get quantitative information about the Brownian motion of the particles, including an accurate determination of their diffusion constant. | Tomfohrde, R. | Tomfohrde, R. | 875x | Blue Binders Optics 3 | ||||||
| 1987-01-01 00:00:00 | Optics | The Investigation of Violin Plate Vibrational Modes by the Method of Holographic Interferometry | A optical configuration was constructed for taking interference holograms. A vibrating violin back plate was used as the subject for the time averaged interferograms. | Demars, Scott D. Bottke, William F. | Demars, Scott D. | Bottke, William F. | 875x | Blue Binders Optics 3 | |||||
| 1987-01-01 00:00:00 | Optics | Deformation Analysis Using Double Exposure Holography | In this experiment double exposure holography is used to measure the strain of a statically determinate aluminum cantilever, a bar that is free at one end and fixed translationally and rotationally at the other. | Williams, Rebecca MacDonald, Larry | Williams, Rebecca | MacDonald, Larry | 875x | Blue Binders Optics 3 | |||||
| 1987-01-01 00:00:00 | Optics | Construction of a Simple Nitrogen Laser | This paper describes the construction and operation of a simple one-pass nitrogen laser. The laser consists of a rectangular discharge cavity mounted on a large parallel plate capacitor. The cavity is made from plexiglass, the capacitor from a two-sided printed circuit board. | Hinze, Jason Bale, Stuart | Hinze, Jason | Bale, Stuart | 875x | Blue Binders Optics 3 | |||||
| 1987-01-01 00:00:00 | Atomic Physics | Langmuir Probe Measurements in a Plasma | We produced a plasma in a system containing argon gas at low pressure by accelerating electrons emitted by heated filaments. After generating the plasma we took current measurements with a Langmuir probe at various vertical, radial, and angular locations. | Keyes, M. Ritman, J. | Keyes, M. | Ritman, J. | 874x | Blue Binders Atomic Physics 3 | |||||
| 1987-01-01 00:00:00 | Particle Experiments | A Study of the Mossbauer Effect, Resonant Absorption of Gamma Rays in Iron-57 | Using both relative attenuation and relative intensity tests, we have succeeded in isolating the 14.4 KeV gamma ray of Fe-57. | MacFarland, Tom O'Neil, Sean | MacFarland, Tom | O'Neil, Sean | 872x | Blue Binders Particle Physics 3 | |||||
| 1987-01-01 00:00:00 | Atomic Physics | Computer Interfaced EPR Spectrometer. | In this project we assembled a constant frequency/ variable field EPR spectrometer. The apparatus was computer interfaced, the computer being used to control the variable field and collect data. | Busch, Darryl Szalapski, Rob | Busch, Darryl | Szalapski, Rob | 874x | Blue Binders Atomic Physics 3 | 87.64.Hd | ||||
| 1987-01-01 00:00:00 | Atomic Physics | An Attempt to Measure the Earth's Magnetic Field by Using Optical Pumping of Rubidium atoms | An attempt to measure the magnetic field of the Earth based upon theory from Benumof and apparatus designed by Haworth and Nagel. | Navratil, Allen Henrich, Peter | Navratil, Allen | Henrich, Peter | 8740 | Blue Binders Atomic Physics 3 | |||||
| 1987-01-01 00:00:00 | Condensed Matter Physics | The Copper X-Ray Spectrum | Our Project deals mainly with the simple features of the copper x-ray spectrum: the bremsstrahlung distribution, as well as the CuK-alpha and CuK-beta x-rays peaks. By reflecting x-rays from parallel planes of a regular cubic crystal, according to the Bragg scattering theorem, we were able to map out the entire copper x-ray spectrum and calculate the energies associated with the different atomic x-ray transittions. | Kammueller, Kevin Chen, Taoqu | Kammueller, Kevin | Chen, Taoqu | 873x | Blue Binders Condensed Matter 4 | |||||
| 1987-01-01 00:00:00 | Condensed Matter Physics | High Temperature Superconductivity: Measuring Tc | We determined the critical temperature for several samples of Yba(2)Cu(3)0(7-x) by measuring the resistivity versus temperature. Preliminary results indicated a Tc around 95K. We will gather data on dependence of Tc on oxygen content, by varying the amount of oxygen the sample receives during preparation. | Volkmuth, Wayne Styczinski, Jim | Volkmuth, Wayne | Styczinski, Jim | 8730 | Not Yet Filed | |||||
| 1987-01-01 00:00:00 | Particle Experiments | A Measurement of the Muon Lifetime | Our experiment attempts to measure the decay time of a muon. (using) a liquid scintillator to detect the decay of atmospheric muons. | Tam, Siu-Yue Schubert, Susan | Tam, Siu-Yue | Schubert, Susan | 872x | File Cabinet | |||||
| 1987-01-01 00:00:00 | Atomic Physics | An Investigation of the Ramsauer Effect. | In our experiment, we studied the phenomenon of a beam of slow moving electrons traveling through a noble gas as if there was no gas present. | Baska, Doug Jacobsen, Todd | Baska, Doug | Jacobsen, Todd | 874x | Blue Binders Atomic Physics 3 | |||||
| 1987-01-01 00:00:00 | Optics | Laser to Single-Mode Fiber Coupling Efficiency | Measurements of efficiency of laser to single-mode fiber power coupling as a function of lateral and angular alignment of beam to fiber are thoroughly explained. | Randall, R. Konicek, P. | Randall, R. | Konicek, P. | 875x | Blue Binders Optics 3 | |||||
| 1986-01-01 00:00:00 | Atomic Physics | The Relaxation Times of Protons in Glycerol, A Pulsed Nuclear Magnetic Resonance Experiment | In this experiment the relaxation times T1 and T2 of protons in a glycerol sample were measured using pulsed nuclear magnetic resonance techniques. | Wollack, Ed Wallace, Noah | Wollack, Ed | Wallace, Noah | 864x | File Cabinet | |||||
| 1986-01-01 00:00:00 | Particle Experiments | Cosmic Ray Extensive Air Shower Studies | The goal of our project was to detect extensive air showers produced in the atmosphere by the highest energy cosmic rays. We have explored the possibility of accomplishing this objective by using photomultiplier tubes to detect the Cerenkov radiation produced by these showers. | Glans, Eric Kunz, James | Glans, Eric | Kunz, James | 862x | Blue Binders Particle Physics 3 | |||||
| 1986-01-01 00:00:00 | Misc | The Sensitivity Reduction Factor of a Fiber Optic Magnetometer Due to Demagnetizing Factor. | The sensitivity of a fiber optic magnetometer (FOM) is limited by the demagnetizing factor of the Ni-Fe coated sensing fiber. Incremental permeability for various sensing fiber lengths is measured. | Strandjord, L. K. Roloff, W. K. Ensaf, P. | Strandjord, L. K. | Roloff, W. K. | Ensaf, P. | 869x | Blue Binders General Physics 2 | ||||
| 1986-01-01 00:00:00 | Atomic Physics | The Double-Plasma Machine | A machine . . . was designed and constructed. Using a Langmuir probe, the machine was tested by measuring the electron temperature and detecting a pulse which was transmitted through two argon plasmas in the machine. | Nguyen, Hogan Weiner, Ann R. | Nguyen, Hogan | Weiner, Ann R. | 864x | Blue Binders Atomic Physics 2 | |||||
| 1986-01-01 00:00:00 | Misc | A 1420 MHz Radio Telescope | When we began our work . . . The overall system design had already been determined and some of the system components were tested and in place. We integrated those components into a working system and tested the system's operational capacity by performing beam pattern and sensitivity measurements. | Huelsnitz, Warren Kelly, Douglas | Huelsnitz, Warren | Kelly, Douglas | 869x | Blue Binders General Physics 2 | |||||
| 1986-01-01 00:00:00 | Atomic Physics | Measurement of the Absorption Cross-Section for Atoms in Monatomic Gases using a Nitrogen Dye Laser | This experiment is an attempt to measure the absorption cross-sections for atoms in monatomic gases at optical frequencies. | Anderson, Craig Apolloni, John | Anderson, Craig | Apolloni, John | 864x | Blue Binders Atomic Physics 2 | |||||
| 1986-01-01 00:00:00 | Condensed Matter Physics | Critical Currents in a Thin Film of Superconducting Tin | The temperature dependence of the critical supercurrent of a thin film of superconducting tin was studied along with the shape of the sample's voltage versus current characteristic at the transition from the superconducting to the normal state at a fixed temperature. | Atkins, Nolan T. Peria, Bill J. | Atkins, Nolan T. | Peria, Bill J. | 863x | Blue Binders Condensed Matter 3 | |||||
| 1986-01-01 00:00:00 | Particle Experiments | The Compton Report | A conceptually simple Compton effect experiment is described which uses two NaI crystal detectors and coincidence techniques to measure scattered photon and Compton electron energies as a function of the scattering angle. | Koehn, Phil Rownd, Jason | Koehn, Phil | Rownd, Jason | 862x | Blue Binders Particle Physics 3 | |||||
| 1986-01-01 00:00:00 | Condensed Matter Physics | Temperature Dependence of Semiconductor Conductivities | An experiment was conducted in which the conductivities of p-type doped germanium, n-type doped germanium, and undoped germanium were measured over a range of temperatures selected to include parts of both the extrinsic and intrinsic regions of conduction for each doped material. | Nease, Brant Buan, John | Nease, Brant | Buan, John | 863x | Blue Binders Condensed Matter 3 | |||||
| 1986-01-01 00:00:00 | Condensed Matter Physics | An Attempt to Measure the Velocity of Third Sound in He-4 Using Capacitive Techniques | We report the (inability) to observe third sound thickness oscillations in unsaturated films of superfluid liquid He-4 using the capacitance technique of J.S. Brooks (Phys. Rev. Lett. 40,242 (1978)) | Nelson, Jeffrey Walsh, William | Nelson, Jeffrey | Walsh, William | 863x | Blue Binders Condensed Matter 3 | |||||
| 1986-01-01 00:00:00 | Optics | A Michelson Interferometer Wavemeter | Our project was to construct a wavemeter, which is a variation of the Michelson interferometer. Our wavemeter is used to compare the frequencies of two coherent light sources. | Etter, Timothy L. Johnson, Mark M. | Etter, Timothy L. | Johnson, Mark M. | 865x | Blue Binders Optics 1 | |||||
| 1986-01-01 00:00:00 | Cosmic Ray Experiments | The Isotope Shift in Hydrogen | The wavelength difference between hydrogen alpha radiation and deuterium alpha radiation is measured. The results are in excellent agreement with the theoretical values. | Partridge, Richard | Partridge, Richard | 862x | Blue Binders Atomic Physics 2 | ||||||
| 1985-01-01 00:00:00 | Optics | Rayleigh Scattering | A nitrogen-pumped tunable dye laser was used as a parallel beam light source, and measurements of elastically scattered light at ninety degrees from a sample of methanol were made. | Vang, Tim Gunderson, Craig | Vang, Tim | Gunderson, Craig | 855x | Blue Binders Optics 1 | |||||
| 1985-01-01 00:00:00 | Atomic Physics | Measuring the Earth's Magnetic Field Through the Use of Optical Pumping. | By using optical pumping of rubidium vapor atoms and by studying the Zeeman splitting of their energy levels, the strength and direction of the Earth's magnetic field can be determined. | Fischer, Timothy J. | Fischer, Timothy J. | 854x | Blue Binders Atomic Physics 2 | ||||||
| 1985-01-01 00:00:00 | Atomic Physics | Nuclear Magnetic Resonance | The goal of the project is to measure Spin-Lattice Relaxation time (T1) and Spin-Spin Relaxation time (T2). In the following experiment we measured T2 ( the spin-spin relaxation time) of a sample of glycerol using pulsed nuclear magnetic resonance. The value of T2 that we measured was 10.8 msec. | Mack, Tony Miller, Brad | Mack, Tony | Miller, Brad | 854x | Blue Binders Atomic Physics 2 | |||||
| 1985-01-01 00:00:00 | Condensed Matter Physics | The Josephson Effect in Superconductors | Condensed electrons or Cooper pairs display a specific type of tunneling through a barrier separating two superconductors. The current that flows by means of this tunneling is known as the Josephson supercurrent. We have observed such a current using a Clarke slug. | Salo, Scott P. Manley, Mark T. | Salo, Scott P. | Manley, Mark T. | 853x | Blue Binders Condensed Matter 2 | |||||
| 1985-01-01 00:00:00 | Condensed Matter Physics | Powder X-Ray Diffraction | This experiment determines the structure and the conventional cell size of an unknown crystal sample via powder diffraction data. | Felton, Steve B. Kemp, Chris J. | Felton, Steve B. | Kemp, Chris J. | 853x | Blue Binders Condensed Matter 3 | |||||
| 1985-01-01 00:00:00 | Condensed Matter Physics | Critical Temperatures of Superconducting Low-Lead Lead-Tin Alloys | We made use of the Meissner effect to investigate the relationship between the critical temperature and composition. | Cain, Brad Chapman, Steve | Cain, Brad | Chapman, Steve | 853x | Blue Binders Condensed Matter 3 | |||||
| 1985-01-01 00:00:00 | Condensed Matter Physics | First Sound Propagation in Liquid Helium | The parameters we measured were the velocity of first sound as a function of temperature and the Q values of first sound resonance in a particular resonator at various temperatures. | Schacht, James Tsai, I-Lun | Schacht, James | Tsai, I-Lun | 853x | Blue Binders Condensed Matter 3 | |||||
| 1985-01-01 00:00:00 | Condensed Matter Physics | Particle Size and Temperature Dependence of the Dielectric Constant of Triglycine Sulfate Powders | Dielectric measurements on powdered TGS have been taken as a function of temperatures for maximum particle diameters of 10, 30, 125, 149 um. | Tarnowski, David J. Wallace, Barton L. | Tarnowski, David J. | Wallace, Barton L. | 853x | Blue Binders Condensed Matter 2 | |||||
| 1985-01-01 00:00:00 | Condensed Matter Physics | Measurements of the Complex Impedance of a Superionic Conductor, Rb Ag4 I5 | Report Missing | Haugen, G. A. Fink, P. J. | Haugen, G. A. | Fink, P. J. | 853x | Blue Binders Condensed Matter 2 | |||||
| 1985-01-01 00:00:00 | Optics | Photo-Mixing Phase Angle | The experiment . . . is designed to measure a quantity that contains information related to the phase angles of reflection and transmission of electromagnetic waves at the boundaries of a thin film. | Dorsey, Tom Plesums, Karl | Dorsey, Tom | Plesums, Karl | 855x | Blue Binders Optics 3 | |||||
| 1985-01-01 00:00:00 | Misc | A Simple Instructional 1420 MHz Radio Telescope System | The design and construction of an amateur radio telescope has been previously described (Swenson). Here, a system is considered which receives at 1420 MHz, the emission frequency of cold atomic hydrogen. The system design goals are low cost, reliability, and ease of use. | Shaver, Leif Wick, Kurt | Shaver, Leif | Wick, Kurt | 859x | Blue Binders General Physics 2 | |||||
| 1985-01-01 00:00:00 | Particle Experiments | Neutron Transmission | We explored the production of fast (about 1 MeV) neutrons using the nuclear reaction B-11(p,n) C-11 induced by protons from a Van de Graaff accelerator. (Note: Used Tandem accelerator) | Hiller, Robert Spanjers, Greg | Hiller, Robert | Spanjers, Greg | 852x | Blue Binders Particle Physics 2 | |||||
| 1985-01-01 00:00:00 | Particle Experiments | Report on Gamma-Gamma Correlation Measurement Project | We have measured the angular correlation between the cascaded gamma?s from Ni-60 following the Beta decay of Co-60 and fit the following theoretical function to our data. (equation) | Byers, John Johnson, Jeff | Byers, John | Johnson, Jeff | 852x | Blue Binders Particle Physics 2 | |||||
| 1985-01-01 00:00:00 | Condensed Matter Physics | Sputtering-Etching Characteristics of Pb-Al Thin Films | Thin films of pure Pb, pure Al, and Pb-Al were vapor deposited on silicon substrates. We obtained depth profiles of each film using Auger electron Spectroscopy and ionized Ar sputter-etching. | Sheehan, John Thurmes, Pete | Sheehan, John | Thurmes, Pete | 853x | Blue Binders Condensed Matter 2 | |||||
| 1985-01-01 00:00:00 | Optics | Determination of Thin Film Thickness by Interference | Thickness measurements were made on thin (0.5-5.0 micron) dielectric films using optical interference. | Dobbins, Scott | Dobbins, Scott | 855x | Blue Binders Optics 1 | ||||||
| 1985-01-01 00:00:00 | Condensed Matter Physics | Q Values of Second Sound Resonance in Liquid Helium | An acoustic resonator was used to measure the Q values of second sound resonances in liquid He II. At a temperature of 1.7 K we found values of 98 to 880 in a frequency range of 1 to 10 kHz. | Silvis, Jeff Clark, Deane | Silvis, Jeff | Clark, Deane | 853x | Blue Binders Condensed Matter 2 | |||||
| 1985-01-01 00:00:00 | Condensed Matter Physics | An Investigation into the Curie Temperature of Gadolinium | The magnetic properties of a gadolinium sample in an inductive coil were studied and found to be strongly dependent upon the geometry of the coil and sample. | Peterson, Brad | Peterson, Brad | 853x | Blue Binders Condensed Matter 2 | ||||||
| 1985-01-01 00:00:00 | Optics | Increasing the Acceptance Angle in Optical Fibers | The following experiment demonstrates that a fiber rotated in a laser light beam will accept light from a wider angle if it has a rounded end on it. | Mross, Clinton B. Kmit, Maryanne | Mross, Clinton B. | Kmit, Maryanne | 855x | Blue Binders Optics 1 | |||||
| 1985-01-01 00:00:00 | Optics | Shuttle Pulse Measurements of Dispersion and Power Loss | A measurement set-up in which partially transparent mirrors were pressed against the fiber ends was proposed in order to determine the length dependence of pulse dispersion and power loss in a step-index multi-mode fiber. | Nease, Brant Buan, John | Nease, Brant | Buan, John | 855x | Blue Binders Optics 1 | |||||
| 1984-01-01 00:00:00 | Misc | A Study of Earth Tides | This study consisted of the design, construction, and use of a tilt meter intended to measure the tilting of the Earth's crust due to gravitational interactions with the moon. | Samuelson, Robert K. | Samuelson, Robert K. | 849x | Blue Binders General Physics 2 | ||||||
| 1984-01-01 00:00:00 | Particle Experiments | Experimental Test of the Temperature-Dependent Shift of the Mossbauer Spectrum | The Mossbauer effect is studied in Fe-57. Specifically, the energy shift of the Mossbauer Spectrum in stainless steel as a function of the source-absorber temperature difference, the Pound-Rebka-Josephson temperature shift, was measured. | Dummer, Dan Ferrell, Jim | Dummer, Dan | Ferrell, Jim | 842x | Blue Binders Particle Physics 2 | |||||
| 1984-01-01 00:00:00 | Particle Experiments | Radiation from Rainwater | We have searched for radioactivity in rainwater. This study was prompted by Dr. George Freier's new theory, which suggests that radiation from radon-222 might play an important role in raindrop formation. | Haines, Paul Johnson, Steve | Haines, Paul | Johnson, Steve | 842x | Blue Binders Particle Physics 2 | |||||
| 1984-01-01 00:00:00 | Particle Experiments | The Variation of Cosmic Ray Muon Intensity with Time and Barometric Pressure | The purpose of this experiment was to measure the variation of cosmic ray muon intensity as a function of time and barometric pressure. While we found no direct correlation between pressure and intensity, we did find some very large (100%) variations in muon intensity as a function of time. | Roelofs, Greg Tang, Karen | Roelofs, Greg | Tang, Karen | 842x | Blue Binders Particle Physics 2 | |||||
| 1984-01-01 00:00:00 | Atomic Physics | ESR Spectrum of Cr(3+) in Synthetic Ruby | The fine structure spectrum of the Cr(3+) in the single crystal of synthetic ruby at 300 K, as a function of rotation of the crystal in an external magnetic field, using electron spin resonance spectroscopy. | Kani, Iraj Johnson, Doug Molin, Jon | Kani, Iraj | Johnson, Doug | Molin, Jon | 844x | Blue Binders Atomic Physics 1 | ||||
| 1984-01-01 00:00:00 | Optics | Period Study of V566 Ophiuchi | Three complete primary minima of the W Ursae Majoris-type binary star system V566 Ophiuchi were observed. | Olson, Timothy S. | Olson, Timothy S. | 845x | Blue Binders Optics 1 | ||||||
| 1984-01-01 00:00:00 | Acoustic | Deterministic Chaos in an LRC Circuit | We verify that a driven non-linear LRC circuit exhibits period-doubling bifurcation, chaotic behavior, and windows of intermittence predicted by recent mathematical theory. In this experiment we also generate return maps for the circuit, and show that these conform to theory. | Mevissen, John Seal, Rebecca Waters, Laurie | Mevissen, John | Seal, Rebecca | Waters, Laurie | 847x | Blue Binders General Physics 1 | ||||
| 1984-01-01 00:00:00 | Atomic Physics | Observations of Time Varying Concentrations of Atmospheric CO2 Using Mass Spectroscopic Techniques. | Observations have been made of time-varying atmospheric CO2 levels near the University of Minnesota physics department. | Montean, Michael Nemzek, Robert Safar, Nabil | Montean, Michael | Nemzek, Robert | Safar, Nabil | 844x | Blue Binders Atomic Physics 1 | ||||
| 1983-01-01 00:00:00 | Atomic Physics | Experimental Measurement of the Proton g Factor | During the spring and summer of 1993, an attempt was made to measure the proton g factor using nuclear magnetic resonance. However, detection of the proton resonance was never achieved. Coauthor Charles Tiku. | Flekke, Gregg A. Pishko, Eugene Sengenberger, Ricardo | Flekke, Gregg A. | Pishko, Eugene | Sengenberger, Ricardo | 834x | File Cabinet | ||||
| 1983-01-01 00:00:00 | Condensed Matter Physics | Critical Temperatures of Superconducting Lead/Tin Alloys | An investigation of the superconducting critical temperatures of lead/tin alloys indicates that low levels of lead impurity in tin raise the critical temperature of the allow to nearly the critical temperature of lead. | Rutkiewicz, Bob Taylor, John Farrell, Jim | Rutkiewicz, Bob | Taylor, John | Farrell, Jim | 833x | Blue Binders Condensed Matter 2 | ||||
| 1983-01-01 00:00:00 | Acoustic | Elimination of Harmonics with a Mute | This experiment compares the sound from a trumpet when the trumpet is played with and without a mute. Our data shows that the mute eliminates some of the lower harmonics of the signal. | Gronseth, Phil Otto, Scott | Gronseth, Phil | Otto, Scott | 837x | Blue Binders General Physics 1 | |||||
| 1983-01-01 00:00:00 | Optics | Absolute Raman Cross Section of Gramacidin-A | The purpose of our experiment was to measure the absolute cross section of Ga under Raman scattering | Anderson, Charles D. Hanson, David | Anderson, Charles D. | Hanson, David | 835x | Blue Binders Optics 1 | |||||
| 1983-01-01 00:00:00 | Condensed Matter Physics | A Primary Measuring Instrument for Small Forces. | Design criteria for an accurate, small sized, low cost, measuring instrument for very small forces. | Van Asten, Francis C. | Van Asten, Francis C. | 833x | Blue Binders General Physics 1 | ||||||
| 1983-01-01 00:00:00 | Condensed Matter Physics | Test of Gravitational Force Dependence on the Inverse Square of Separation Length of Lab Distances | Our experiment was designed to test the Newtonian law of gravitation; in particular it was our intention to check the validity of the r^2 dependence of less than 10 centimeters. Co-author Peter Rekow. | Asimos, George Dummer, Daniel Chaniotakis, Manos | Asimos, George | Dummer, Daniel | Chaniotakis, Manos | 833x | Blue Binders General Physics 1 | ||||
| 1983-01-01 00:00:00 | Condensed Matter Physics | Cloud Charges | To study the mechanics of charge separation in storm clouds, via the use of simulated cloud conditions. | Ryan, Greg Wagener, Fred Olson, Shaun | Ryan, Greg | Wagener, Fred | Olson, Shaun | 833x | Blue Binders General Physics 1 | ||||
| 1983-01-01 00:00:00 | Condensed Matter Physics | Superconducting Critical Temperatures of Low Lead Concentration Lead/Tin Alloys | An investigation of the superconducting critical temperatures of tin/lead allows indicates that low concentrations of lead in tin raises the critical temperature of the allow to nearly the critical temperature of pure lead. The crucial area appears to be around 5% lead in tin. | Schult, Dennis T. | Schult, Dennis T. | 833x | Blue Binders Condensed Matter 2 | ||||||
| 1983-01-01 00:00:00 | Particle Experiments | Semiconductor Memory Chip Failures Due to Charged Particles | We intended to investigate the effects of charged particles on silicon memory chips. Specifically, the effect of beta rays (electrons) on the MCM 5810 (1K RAM, Motorola). Note: No observed failure in over 100 hours of running the experiment. | Nelson, Charles Clinton, Robert | Nelson, Charles | Clinton, Robert | 832x | Blue Binders Particle Physics 2 | |||||
| 1983-01-01 00:00:00 | Particle Experiments | Induced EMFs in Flames | An experiment in Magneto-Hydrodynamic (MHD) power generation. Although the present experiment did not efficiently generate power, it demonstrated that rapidly moving charged particles were present in the flames. Co-authored by Todd (1983) | Amundson, Derubeis, Steinmetz, | Amundson, | Derubeis, | Steinmetz, | 832x | Blue Binders General Physics 1 | ||||
| 1983-01-01 00:00:00 | Optics | An Undergraduate Experiment for Measuring the Velocity of Light | A simple, easily constructed, and convincing experiment is developed for measuring the velocity of light in air. This technique can be used as a demonstration experiment or as an exercise in an undergraduate physics lab. | Spannring, Ron Marchand, Louis | Spannring, Ron | Marchand, Louis | 835x | Blue Binders Optics 1 | |||||
| 1983-01-01 00:00:00 | Particle Experiments | Laboratory Report: Compton Scattering | The goal of this experiment is to measure E' (energy of scattered photon) and the recoil electron energy E(e)=E-E' and compare the measurements with the prediction . . . , thereby testing the Compton hypothesis that what takes place can be considered an elastic collision between discrete particles. | Rosen, David | Rosen, David | 832x | Blue Binders Particle Physics 2 | ||||||
| 1983-01-01 00:00:00 | Condensed Matter Physics | Speed of Second Sound in Liquid Helium II | We measured the speed of second sound in liquid helium II as a function of temperature. We were able to get a fairly accurate method of getting immediate results compared to the previous methods of waiting until the experiment was done. | Goldstein, Authur Scofield, Paul | Goldstein, Authur | Scofield, Paul | 833x | Blue Binders Condensed Matter 2 | |||||
| 1983-01-01 00:00:00 | Particle Experiments | A Study of Secondary Cosmic Rays | This experiment consisted of the design, construction, and testing of a scintillator detector to study secondary cosmic rays. co-author Uwe Thomanschefsky | Meyer, Bill Samuelson, Bob Scmid, Pete | Meyer, Bill | Samuelson, Bob | Scmid, Pete | 832x | Blue Binders Particle Physics 1 | ||||
| 1983-01-01 00:00:00 | Condensed Matter Physics | Quantization of Liquid Crystal Film Thickness | This experiment . . . Investigates the third dimension -- the thickness of liquid crystal films. We wish to investigate how optical techniques (reflectivity) are used to measure this and confirm what recent experiments have shown, that the thickness of these films is quantized into layers. | Dudero, Phillip Fell, Tim | Dudero, Phillip | Fell, Tim | 833x | Blue Binders Condensed Matter 2 | |||||
| 1982-01-01 00:00:00 | Condensed Matter Physics | Absorption and Resorption Currents in Teflon (Polytetrafluoroethylene) | We reproduced data obtained by previous studies of absorption and resorption currents in Teflon capacitors which have shown totally reversible currents obeying the relationship I=At^-n, n about = 1. | Nisson, Joel Stark, John Williams, Paul | Nisson, Joel | Stark, John | Williams, Paul | 823x | Blue Binders Condensed Matter 1 | ||||
| 1982-01-01 00:00:00 | Nonlinear Systems | Measuring Gravity | Our experiment consisted of four coils that stopped and started timing circuits by the pulse induced in them when a magnet passed through after having been dropped. | Finseth, Steve Greenwald, Tom Picard, Mike | Finseth, Steve | Greenwald, Tom | Picard, Mike | 828x | Blue Binders General Physics 1 | ||||
| 1982-01-01 00:00:00 | Acoustic | 1/f (flicker) Noise in Animal Audio Signals | We show that, within the range of frequencies studied, the power spectra of the animal audio signals studied exhibit a similar 1/f behavior to that of music and human speech. | Boxrud, John J. Franklin, Julie E. | Boxrud, John J. | Franklin, Julie E. | 827x | Blue Binders General Physics 1 | |||||
| 1982-01-01 00:00:00 | Optics | Speed of Light by Microwave Interference | The speed of light is obtained by knowing the microwave source frequency and from measuring the number of beats for a particular distance traveled by a moving object. | Vernstrom, George Golben, John | Vernstrom, George | Golben, John | 825x | Blue Binders Optics 1 | |||||
| 1982-01-01 00:00:00 | Atomic Physics | Using DPPH as a Standard in the Determination of the Lande Spin Factor,g, Using ESR. | An ESR experiment using DPPH as a reference. | Horowitz, J. Scott | Horowitz, J. Scott | 824x | Blue Binders Atomic Physics 1 | ||||||
| 1982-01-01 00:00:00 | Condensed Matter Physics | Measuring the Work Function of a Metal Alloy and the Value of h/e Using the Photoelectric Effect | A procedure for measuring both the work function of a metal alloy and the value of h/e is described in detail. | Knox, Ralph Kangas, Cary Palagi, Mark | Knox, Ralph | Kangas, Cary | Palagi, Mark | 823x | Blue Binders Condensed Matter 1 | ||||
| 1982-01-01 00:00:00 | Particle Experiments | The Muon Lifetime Measurement Experiment | We have measured the lifetime of cosmic ray muons in scintillator oil. . . Using the data of 5200 events collected over 2.5 days. | Fujisawa, Hiroshi Brown, Robert | Fujisawa, Hiroshi | Brown, Robert | 822x | Blue Binders Particle Physics 1 | |||||
| 1982-01-01 00:00:00 | Particle Experiments | An Analysis of Background Radiation as it Affects the Study of Cancer | Tests on the normal background radiation reveal an initial rise followed by a decline as a function of the number of floors from the roof of a university research building. | Van Asten, Francis C. | Van Asten, Francis C. | 822x | Blue Binders Particle Physics 2 | ||||||
| 1982-01-01 00:00:00 | Particle Experiments | Neutron Energy Spectrum (1-100ev) for 92-U-238 (p,n) | This experiment was intended to measure the neutron energy spectrum in the range 1-100 ev for proton induced fission of U-238 by the time of flight method. | Johnson, Jeff C. | Johnson, Jeff C. | 822x | Blue Binders Particle Physics 1 | ||||||
| 1982-01-01 00:00:00 | Particle Experiments | Single Photon Emission Tomography | The sensitivity and resolution of a single photon Emission Computerized Tomography imaging system (ECT) was evaluated. | Mollo, Subec | Mollo, Subec | 822x | Blue Binders Particle Physics 1 | ||||||
| 1982-01-01 00:00:00 | Acoustic | Impedance of Tubes | In the brass and reed woodwind instruments . . . When (bursts of air) are of the proper frequency, they coincide with a pressure maxima at the mouthpiece of the instrument. The playing frequencies of the instrument coincide with the frequencies of the impedance maxima of the instrument. | Adams, John Landis, Brian | Adams, John | Landis, Brian | 807x | Blue Binders Optics 1 | |||||
| 1982-01-01 00:00:00 | Condensed Matter Physics | A Measurement of the Sputtering Rate for He3 Ions on Thin Films of Pd. | Using a W filament in a vacuum chamber, Pd was evaporated onto glass slides to various depths. Simultaneous deposition on an independently calibrated crystal oscillator provided thickness measurements for these deposits. | Kenny, T Hobbie, E | Kenny, T | Hobbie, E | 823x | Blue Binders Condensed Matter 1 | |||||
| 1981-01-01 00:00:00 | Atomic Physics | An Examination of Electron Spin Resonance | This paper outlines the elements of electron paramagnetic resonance (EPR) techniques. This paper gives the theory, equipment and significance of EPR research, along with the results of our experiment with DPPH and CuSO4-7H2O | Hirsch, M. Osen, J. | Hirsch, M. | Osen, J. | 814x | Blue Binders Atomic Physics 1 | |||||
| 1981-01-01 00:00:00 | Atomic Physics | Electron Paramagnetic Resonance Spectra and g Factor of a Free Radical Salt | A sharp first derivative DPPH peak was observed with a center g value of 1.957+/-0.003 and a line width of 10 gauss. Spectra of Cu(SO4)-H2O and MnCl2-4H2O were also observed. | Souther, Larry Hogenkamp, Harry | Souther, Larry | Hogenkamp, Harry | 814x | Blue Binders Atomic Physics 1 | |||||
| 1981-01-01 00:00:00 | Atomic Physics | Measurement of the g-factor | We determined the g-factor of DPPH, Cu and Mn. | Arbogast, Todd Higashi, Robert | Arbogast, Todd | Higashi, Robert | 814x | Blue Binders Atomic Physics 1 | |||||
| 1981-01-01 00:00:00 | Condensed Matter Physics | Second Sound Velocity in Liquid He4 | This paper describes a method of measuring the velocity of second sound by measuring the travel time of heat pulses injected into a cylinder immersed in liquid helium. | Leyh, Ron Knutson, Zach | Leyh, Ron | Knutson, Zach | 813x | Blue Binders Condensed Matter 1 | |||||
| 1981-01-01 00:00:00 | Condensed Matter Physics | The Verification of Second Sound's Velocity | The velocity of temperature waves (second sound) in liquid helium II has been determined to be a function of temperature in the range of 1.4 K to 2.125 K. A time of flight method was used. | Orr, Brad Olsen, Noreen | Orr, Brad | Olsen, Noreen | 813x | Blue Binders Condensed Matter 1 | |||||
| 1981-01-01 00:00:00 | Condensed Matter Physics | Measurement of h/e Using the A.C. Josephson Effect. | Measurement of the period of this (the magnetic field through the junction) oscillation provides an evaluation of the ratio of Planck's constant to the electron charge. | Arndt, Thomas | Arndt, Thomas | 813x | Blue Binders Condensed Matter 1 | ||||||
| 1981-01-01 00:00:00 | Condensed Matter Physics | The Relation of Temperature and Resistance at Low Temperatures in a Resistor | The low temperature characteristics of an 87 ohm resistor are discussed in this paper. | Orr, Brad Olsen, Noreen | Orr, Brad | Olsen, Noreen | 813x | Blue Binders Condensed Matter 1 | |||||
| 1981-01-01 00:00:00 | Particle Experiments | Measurements of the Lifetime of Muons produced from the Decay of Pi Mesons in secondary Cosmic Rays | We have measured the distribution function of the decay times of muons and found that the distribution curve was best fitted by a decreasing exponential with a time constant Tau=2.18 +/- 0.1 microsecond. | Copie, T. B. Pearson, N. M. | Copie, T. B. | Pearson, N. M. | 812x | Blue Binders Particle Physics 1 | |||||
| 1981-01-01 00:00:00 | Particle Experiments | A Measurement of the Muon Lifetime | Five values of the lifetime were measured. The first three values were obtained with successively more complex apparatus, and the final two were obtained with modifications of the most complex set-up. | Blilie, Charles Horberg, Shelley | Blilie, Charles | Horberg, Shelley | 812x | Blue Binders Particle Physics 1 | |||||
| 1981-01-01 00:00:00 | Condensed Matter Physics | Curie Temperature of Gadolinium | In this experiment an attempt was made to find the Curie temperature of Gadolinium. Gadolinium is ferromagnetic and has a maximum magnetic susceptibility at its Curie temperature. | King, James Schram, Rick | King, James | Schram, Rick | 813x | Blue Binders Condensed Matter 1 | |||||
| 1981-01-01 00:00:00 | Atomic Physics | "Yet Another Optical Pumping Experiment" | A relatively simple experiment can be set up to observe the phenomenon of optical pumping. If the magnitude of the Earth's local magnetic field is known, the apparatus can be used to confirm the values of the angular momenta of the nuclei of rubidium isotopes. | Brekke, Lee Feyma, Dan | Brekke, Lee | Feyma, Dan | 814x | Blue Binders Atomic Physics 1 | |||||
| 1980-01-01 00:00:00 | Optics | A Speed of Light Measurement Technique | We have developed a speed of light measurement of low cost and relative ease of use, suitable as an undergraduate laboratory project. | Gogins, Mark Khosraui, Fereidoon | Gogins, Mark | Khosraui, Fereidoon | 805x | Blue Binders Optics 1 | |||||
| 1980-01-01 00:00:00 | Optics | Some Properties of the Sodium Doublet | We have measured (1) the mean wavelength of the Na doublet, (2) the separation of the doublet wavelengths, (3) their spectral widths, and (4) the coherence length. | Biglow, Lawrence Amin, Abu | Biglow, Lawrence | Amin, Abu | 805x | Blue Binders Optics 1 | |||||
| 1980-01-01 00:00:00 | Acoustic | Flicker (1/f) Noise in Music and Speech | Account is given of the spectral densities of the audio power of different types of music and speech. Time averages were only over the length of the individual piece, which was always less than 4 minutes. | Lindahl, Kerry M. | Lindahl, Kerry M. | 807x | Blue Binders General Physics 1 | ||||||
| 1980-01-01 00:00:00 | Acoustic | Spectral Decomposition of Music | Structure and rhythm of a variety of musical types are examined. Power spectrum of music exhibits an approximate 1/f response. The relationship was discovered by R.F. Voss. | Miller, Ted Stenstrom, Richard | Miller, Ted | Stenstrom, Richard | 807x | Blue Binders General Physics 1 | |||||
| 1980-01-01 00:00:00 | Optics | Coherent Optical Information Processing Systems | By using a system of lenses it is possible, by the use of spatial filters, to process optical information in a manner that blocks out pre-chosen information. These optical filters consist of transparencies which are inserted in an appropriate location in the optical system. | Boike, Leonard L. | Boike, Leonard L. | 805x | Blue Binders Optics 1 | ||||||
| 1980-01-01 00:00:00 | Optics | Making and Viewing Transmission Holograms | We made a transmission hologram by creating an interference pattern on a photographic medium (emulsion) by exposing the medium to two beams of coherent light,both originating from the same HeNe laser. . . (coauthor William Putikka) | Boike, Leonard L. Evans, Darrell Kanayo, Abanukam | Boike, Leonard L. | Evans, Darrell | Kanayo, Abanukam | 805x | Blue Binders Optics 1 | ||||
| 1980-01-01 00:00:00 | Optics | Vacuum Vapor Deposition Control via Optical Monitoring | An attempt was made to duplicate the function of an Inficon Sentinel 200 continuous evaporation process controller. | Christenson, Kurt Franklin, Julie | Christenson, Kurt | Franklin, Julie | 805x | Blue Binders Optics 1 | |||||
| 1980-01-01 00:00:00 | Condensed Matter Physics | Investigation of the Current Carriers in N and P Type Germanium | Using the doped Ge bars from the AAPT set we measured the minority lifetime, the mobility (mu), and the diffusion coefficient D. | Peterson, Vince | Peterson, Vince | 803x | Blue Binders Condensed Matter 1 | ||||||
| 1980-01-01 00:00:00 | Condensed Matter Physics | Energy Gap in Superconducting Films | By measuring the current-voltage characteristic due to the Quantum mechanical tunneling effect across two superconducting metals separated by a thin insulating film, we have observed the non-linear curve which (agrees with) the Bardeen, Cooper, Schrieffer theory. | Bandli, Timothy J. Blaha, Cynthia A. Bot, Lawrence V. | Bandli, Timothy J. | Blaha, Cynthia A. | Bot, Lawrence V. | 803x | Blue Binders Condensed Matter 1 | ||||
| 1980-01-01 00:00:00 | Condensed Matter Physics | An Investigation Into a Josephson Junction Analog's Critical Exponents | This paper reports on a PLL Josephson Junction analog's behavior for large (Omega). | Couture, William Schnider, Kurt | Couture, William | Schnider, Kurt | 803x | Blue Binders Condensed Matter 1 | |||||
| 1980-01-01 00:00:00 | Condensed Matter Physics | Experiments on Semiconductor Material | We measured the minority lifetime, resistance as a function of temperature, diode voltage as a function of current, and the drift mobility in Germanium. | Martinez, Kurt Peterson, Vince | Martinez, Kurt | Peterson, Vince | 803x | Blue Binders Condensed Matter 1 | |||||
| 1980-01-01 00:00:00 | Particle Experiments | Ionization Chamber and Electrometer Circuit | The goal of my experiment was to measure and study the variation in ionization current with applied voltages for different gases, pressures and radiation. | Denzer, Scott | Denzer, Scott | 802x | Blue Binders Particle Physics 1 | ||||||
| 1980-01-01 00:00:00 | Condensed Matter Physics | Glow Discharge | The purpose of this experiment was to investigate the electrical discharge between two electrodes inside a tube containing air. The experiment was also performed with a helium filled tube. | Heinze, Terrell G. | Heinze, Terrell G. | 803x | Blue Binders General Physics 1 | ||||||
| 1980-01-01 00:00:00 | Particle Experiments | Experimental Physics Diffusion Cloud Chamber | This chamber used a methyl alcohol vapor at atmospheric pressure and was particularly desirable because of its simplicity . . .it required no complicated heating and refrigerating systems . . . and could be made entirely out of Plexiglas. | Schram, Rick King, James | Schram, Rick | King, James | 802x | Blue Binders Particle Physics 1 | |||||
| 1980-01-01 00:00:00 | Optics | Speed of Light Measurement Using a Pockels Cell | We attempted to measure the speed of light by phase retardation using a pockels cell. | Goppelt, David Tang, Andrew | Goppelt, David | Tang, Andrew | 805x | Blue Binders Optics 1 | |||||
| 1971-01-01 00:00:00 | Condensed Matter Physics | Semiconductor Resistance Experiment | The mechanism of solid state conduction is investigated through the use of temperature dependent processes. . . . Samples of N and P type Germanium were subjected to high and low temperatures while their resistance was monitored. | Giganti, J. R. | Giganti, J. R. | 713x | Blue Binders Condensed Matter 1 | ||||||
| 1971-01-01 00:00:00 | Particle Experiments | The Ionization Chamber | This experiment uses an ionization chamber and electrometer circuit to study the variation of ionization current with applied voltage for 3 different gases, helium, argon, and air at different pressures, 0.5, 1, 1.5 atmospheres, using alpha particles and gamma rays as sources of ionizing radiation. | Hinz, Mike | Hinz, Mike | 712x | Blue Binders Particle Physics 1 | ||||||
| 1971-01-01 00:00:00 | Condensed Matter Physics | Semiconductor Resistance | The resistance values of one sample of p type and one sample of n type germanium crystal are measured over a temperature range of approximately -190 C to 200 C. | Cristoffel, John | Cristoffel, John | 713x | Blue Binders Condensed Matter 1 | ||||||
| 1970-01-01 00:00:00 | Condensed Matter Physics | X-ray Diffraction | This experiment uses x-ray diffraction to determine the structure of a crystal. Working with known structures and then verifying the accepted results. | Rye, Ralph J. | Rye, Ralph J. | 703x | Blue Binders Condensed Matter 1 | ||||||
| 1970-01-01 00:00:00 | Atomic Physics | Electron Paramagnetic Resonance | An r-f bridge and lock-in-amplifier detection system have been used to measure the Lande g-factors of DPPH and CuSO4. | Bargabus, David | Bargabus, David | 704x | Blue Binders Atomic Physics 1 | ||||||
| 1970-01-01 00:00:00 | Atomic Physics | Electron Paramagnetic Resonance | 1) the calibration of a Nuclear magnetic resonance gaussmeter, (2) the observation of electron paramagnetic resonance spectrum of DPPH in both the concentrated solid form and in dilute liquid samples, and the observation of the electron p.m. spectrum of rare earth impurities in CaCl2 xtals. | Franey, Michael | Franey, Michael | 704x | Blue Binders Atomic Physics 1 | ||||||
| 1970-01-01 00:00:00 | Condensed Matter Physics | Laue Diffraction of X-rays | Through the use of Laue transmission photographs, we attempted to understand how X-rays can be used to give valuable information on the structure of crystals, NaCl in particular. | King, Gary | King, Gary | 703x | Blue Binders Condensed Matter 1 | ||||||
| 1970-01-01 00:00:00 | Particle Experiments | Calibration of Time Coincidence Equipment | Calibration of the base line and the discriminator bias controls, and a measurement of the resolving time were performed using a Sturrup time coincidence unit. | Johnson, Brian C. | Johnson, Brian C. | 702x | Blue Binders Particle Physics 1 | ||||||
| 1970-01-01 00:00:00 | Particle Experiments | The Mossbauer Effect | This experiment consisted of observing the Mossbauer effect using a ten millicurie Co57 source and several different absorbers, including Stainless steel, Iron, and Iron oxide. | Gensmer, Charles | Gensmer, Charles | 702x | Blue Binders Particle Physics 1 | ||||||
| 1970-01-01 00:00:00 | Particle Experiments | Characteristics of the Geiger Counter | The objective . . . of this experiment is to test statistical distribution for various counting rates against the parent distribution and to determine dead time of the Geiger-Muller tube by the two source method. | Sjolander, Gary W. | Sjolander, Gary W. | 702x | Blue Binders Particle Physics 1 | ||||||
| 1970-01-01 00:00:00 | Particle Experiments | Electron Optics | The foci and principal planes for a symmetric two tube electrostatic lens are determined as a function of voltage ratio. | Salo, Rodney | Salo, Rodney | 702x | Blue Binders Particle Physics 1 | ||||||
| 1970-01-01 00:00:00 | Particle Experiments | Slow Neutron Experiment | . . . an experiment which was designed to measure the stopping distance of thermal neutrons and indium resonance neutrons in water. | Koepke, James A. | Koepke, James A. | 702x | Blue Binders Particle Physics 1 | ||||||
| 1970-01-01 00:00:00 | Particle Experiments | The Scintillation Counter | Investigations of the energy spectra of several gamma ray sources (Na-22, Co-60, and Cs-137) and of characteristic K-alpha x-rays for lead and tantalum were conducted using a NaI(Tl) scintillation counter. | Meyer, Edward Mcleod, Gary | Meyer, Edward | Mcleod, Gary | 702x | Blue Binders Particle Physics 1 | |||||
| 1970-01-01 00:00:00 | Particle Experiments | Alpha Range and Stopping Power Experiment | The range of naturally occurring alpha radiation from 212-Bi and 212-Po was determined in air and in argon. | Giganti, J. R. | Giganti, J. R. | 702x | Blue Binders Particle Physics 1 | ||||||
| 1970-01-01 00:00:00 | Condensed Matter Physics | Test of Superconducting Solenoid | The objective of our work is to obtain a persistent field of 5000 gauss in a superconducting solenoid and to be able to measure this field with a search coil. | Sjolander, Gary W. | Sjolander, Gary W. | 703x | Blue Binders Condensed Matter 1 | ||||||
| 1970-01-01 00:00:00 | Condensed Matter Physics | The Thermal Characteristics of Helium and of Carbon Resistors at Low Temperatures | The temperature dependencies of thermal waves in liquid helium and of a carbon-composition resistor immersed in the liquid are discussed. | Riess, Robert | Riess, Robert | 703x | Blue Binders Condensed Matter 1 | ||||||
| 1970-01-01 00:00:00 | Condensed Matter Physics | Low Temperature | Theory and history of second sound and resistance thermometers are presented. Results of second sound are compared with Lane and Fairbank and Clement and Quinnell's semi-empirical resistance-temperature constants are computed. | Hoglund, Barry Johnson, Neil L. | Hoglund, Barry | Johnson, Neil L. | 703x | Blue Binders Condensed Matter 1 | |||||
| 1970-01-01 00:00:00 | Atomic Physics | The Franck-Hertz Experiment | . . . An experiment . . . Designed to measure the excitation energy of the mercury atom corresponding to the prominent mercury spectrum line at 2537 Angstroms. | Koepke, James | Koepke, James | 704x | Blue Binders Atomic Physics 1 |