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imagerteleconnotes20180405 [2018/04/04 10:46] – created hananyimagerteleconnotes20180405 [2018/04/04 15:43] (current) wenxx181
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-====== Telecon 20180405 ======+====== Telecon 20180404 ======
  
-Attending: +Attending: Kris,Brian, Toki, Tom, Jeff, Shaul, Karl, Qi
  
-Notes by : +Notes by : Qi
  
 === Agenda=== === Agenda===
 +
 +  * SPIE Papers 
 +    * {{::sutinspie_pico_v8.docx|Sutin Abstract}}
 +    * {{::kyoung_abstract_pico_spie_2018_v2.doc|Young Abstract}}
 +  * TeamX
 +    * {{::finalfocalplane_20180404.pptx|Final Focal Plane configuration}} 
 +    * {{::banddefinitions_v3.2.xlsx|Latest noise budget V3.2}} 
 +  * Setting Margins
 +    * {{::pico_sensitivity_calculations_teamx.pptx|PICO Noise Assumptions}}
 +  * {{::picoscienceprogram2.pdf|Any suggestions for workshop?}} 
 +
 +=== Notes ===
 +  * SPIE
 +    * in June, mostly technical
 +    * Apr 9, deadline for finalizing the author list and material 
 +
 +  * TeamX meeting
 +    * 2nd Instrument meeting; Mission meeting
 +    * Overall cost is the the most important product
 +    * no significant revelation
 +    * Focal plane
 +      * converged to one configuration; most compact, proper strehl ratio for high frequency
 +      * the other two, we have to change the optical design, to accommodate with high frequency
 +      * this focal plane has largest number of detectors; the difference compared to other two is very small though.
 +
 +  * Noise budget
 +    * V3.2: very little change from V3.1; noise 0.63 uK arcmin before, now 0.61 uK arcmin
 +    * compare values with CORE and LiteBird calculation, single detector
 +    * we are using two independent codes to calculate. Karl at UMN; Roger at JPL. Agree within 5%, slightly difference. Reasonable confidence. 
 +    * various assumptions
 +      * to what extend our assumptions agree with other experiments
 +      * in some bands, noise lower than LIteBird, some bands higher than LiteBird.
 +      * everything seems consistent, no major change
 +      * Psat, safety factor of 2, we haven chosen a factor of 2, it’s used by JPL folks, also by SPIDER AND KECK. We thought it’s reasonable.
 +      * Quantitative calculations will be done by next week: what T of elements (mirros) could bring us to a factor of 2
 +      * Efficiency
 +        * It varies between the bands
 +        * Detector: lenselet + antenna + bolo, 70%
 +        * Edge Taper: center 10 db, lower band and higher band have different values; low, center, high: 70%, 90%, 99%.
 +        * End to end, 50-70%
 +        * Optical efficiency can mess up the estimate on safety factor
 +      * Emissivity
 +        * We are using measured emissivity from Planck. We already know, for highest bands, we may need to change to be more conservative
 +
 +  * Margins
 +    * Space Mission, “current best estimate”, e.g. 100% yield; we are not likely to do better than 0.61 uK arkmin
 +    * What margin is the judge, successful or not.
 +    * Two paths: 
 +      * 1. start with assumptions 
 +        * each one assumption
 +        * "worst case"
 +      * 2. We can propagate backs from sigma_r 2*10^-5. 
 +      * 3. maybe a 3rd one, some factors on NET. 
 +      * Kris: instrument is one thing, how to get data to science is another
 +      * Raphael used mapping speed, assuming delensing on our own resolution. 1*10^-4 is the limit that Shaul said in AAS, which has margins from calculated value 2*10^-5.
 +        * It's not a trivial calculation
 +    * LiteBird 
 +      * does have margins
 +      * "large sections", different categories, based on what's typically achieved in lab and by ground experiments
 +      * quote r with margin in it
 +      * nominal performance and worst performance. Give both to science team. Worst case did not give too much science. Lately, increase number of detectors to improve “worst case”
 +    * Shaul is going to check with Planck team
 +
 +  * Workshop
 +    * suggestions:
 +      * Kris: 1) without modulator 2) arguments on margins
 +
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imagerteleconnotes20180405.1522856814.txt.gz · Last modified: 2018/04/04 10:46 by hanany