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imagerteleconnotes20170731

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imagerteleconnotes20170731 [2017/07/31 14:09] – bjohnsonimagerteleconnotes20170731 [2017/08/04 10:43] (current) – kyoung
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     *  {{::opendragone_packing_20170731.pdf|Update on packing of optical systems (UMN)}}     *  {{::opendragone_packing_20170731.pdf|Update on packing of optical systems (UMN)}}
     * Ray tracing examination of stray light and DLFOV comparison, {{::opticsstudy_20170731.pdf|Optics Study 2017-07-31}} (UMN)     * Ray tracing examination of stray light and DLFOV comparison, {{::opticsstudy_20170731.pdf|Optics Study 2017-07-31}} (UMN)
-    * Firing up far sidelobe analysis, {{::opticsstudy_20170731.pdf|Optics Study 2017-07-31}} (Brad)+    * Firing up far sidelobe analysis, {{::tran_et_al_2010.pdf|Tran et al. (2010)}} (Brad)
     * Anyone at JPL to run GRASP? (Amy)     * Anyone at JPL to run GRASP? (Amy)
     * Are we using the right shield geometry? (Amy)     * Are we using the right shield geometry? (Amy)
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     * Hydrazine or flywheels? What are reasonable spin and precession rates? (Amy)     * Hydrazine or flywheels? What are reasonable spin and precession rates? (Amy)
   * Focal Plane    * Focal Plane 
-    * current baseline: multi-chroic TES; anyone interested in developing other options so that we can point to concrete alternatives (e.g. KIDs)? +    * current baseline: multi-chroic TES; anyone interested in developing other options so that we can point to concrete alternatives (e.g. KIDs)? {{::2017_bjohnson_ltd17.pdf|multi-chroic MKIDs}}
     * Questions for the baseline (Jeff, Roger)      * Questions for the baseline (Jeff, Roger) 
       * what is the plan for detector technology for the high frequency bands of the imager?       * what is the plan for detector technology for the high frequency bands of the imager?
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 __Actions:__ __Actions:__
 +  * UMN, investigate DLFOV trade-off between crossed and open dragone
 +  * Amy, determine cost difference for larger mirrors
 +  * Brad, determine sidelobe analysis done for EPIC.  How was galaxy contamination accounted for.
 +  * Amy, find if anyone at JPL to run GRASP analysis.
 +  * Amy, begin a matrix of possible science outputs.
 +
 +
 +__Notes:__
 +
 +Attending: Jeff, Mike, Jamie, Julian, Shaul, Karl, Qi, Amy, Roger, ??
 +
 +Optics
 +  * Packing the open dragone.  The focal plane can be placed near the bus at 2-3 degree penalty in alpha.
 +  * Ray trace of possible sidelobes
 +     * cross dragone has clipping sidelobe as discussed previously
 +     * open dragone has no similar sidelobe.  Is straightforward to baffle.
 +  * comparison of DLFOV
 +     * when scaled by F*lambda open Dragone gives ~60% of the focal plane diameter of the crossed
 +     * however crossed will require larger pixels (large edge taper) to control sidelobes, while open can have small pixels (low edge taper) since sidelobes are controlled by baffling.
 +     * **UMN** to further investigate DLFOV trade-off between the systems
 +  * Goal of settling on system in 3-4 weeks.  **Amy** to look into cost difference for larger physical mirrors in the open dragone case.
 +  * Physical optics analysis:
 +     * Brad can run GRASP once a system is designed.
 +     * For EPIC  GRASP simulations were convolved with galaxy map to get polarization leakage.
 +        * **Brad** will continue investigating details of what was done.
 +        * Julian can also run full time domain simulations if/when needed.
 +     * JPL has a GRASP license.  **Amy** checking for person to run analysis.
 +
 +Scan
 +  * Julian points to work done for LiteBIRD({{::litebird_toast_20170123.pdf|LiteBIRD Scan Internal Memo}}) and CORE (https://arxiv.org/pdf/1707.04224.pdf). 
 +     * LiteBIRD looked at full focal plane and assessed uniformity of coverage, angle of attack of each pixel, beam distortion from spin and precession speeds, ability to calibrate on dipole.
 +       * saw broad minimum in coverage uniformity for alpha = 25-65 deg.
 +       * narrower range where dipole signal is strong for all scans.
 +       * condition is good with and without HWP (for full focal plane)
 +     * CORE looked at single detector maps to asses ability to control systematics.
 +     * further constraints on CMBP scans need our own simulation.  The machinery for this exists.
 +  * Decision to take alpha + beta = 95 deg as the standard for now, no reason for 100 deg.
 +  
 +Focal Plane
 +  * delayed to next week due to time.
 +  * one key question is the need to go to 800 GHz.  
 +    * needs input from Galactic science group
 +    * **Amy** will start a matrix of science outputs to help communicate between science goals and design trade-offs.
 +
 +
imagerteleconnotes20170731.1501528175.txt.gz · Last modified: 2017/07/31 14:09 by bjohnson

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