Campuses:
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| imagerteleconnotes20171128 [2017/11/28 13:56] – kyoung | imagerteleconnotes20171128 [2017/12/05 13:39] (current) – hanany | ||
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| ====== Telecon 20171128 ====== | ====== Telecon 20171128 ====== | ||
| - | Attending: | + | Attending: |
| - | Notes by : \\ | + | Notes by : Karl \\ |
| === Agenda=== | === Agenda=== | ||
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| * Readout mux factor, wire count (Roger?) | * Readout mux factor, wire count (Roger?) | ||
| * Temperature stability from Planck? | * Temperature stability from Planck? | ||
| + | * Sun Shield configurations: | ||
| + | * {{:: | ||
| === Notes:=== | === Notes:=== | ||
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| Matt | Matt | ||
| - | |||
| ---- | ---- | ||
| + | __Minutes__ | ||
| + | |||
| + | Focal plane and noise: | ||
| + | * **Karl** to make memo of all assumptions going into these calculations | ||
| + | * Using curved focal plane with larger DLFOV. | ||
| + | * More flexibility in number pixels per band, can trade synchrotron pixels for CMB pixels | ||
| + | * with larger mirrors can do 28k bolos. | ||
| + | * CMB sensitivities for cases discussed last week. | ||
| + | * Numbers in presentation. | ||
| + | * Biggest effects: | ||
| + | * Emissivity to 0.06% from 1%, 20% gain in sensitivity | ||
| + | * stop to 6.5 K from 4 K, 10 % loss in sensitivity | ||
| + | |||
| + | Aside: observing efficiency | ||
| + | * Continuous 100% ? vs single shot 80-85% ADR | ||
| + | * Toki: may need downtime for data transfer. | ||
| + | * Jeff: SPIDER saw problems. | ||
| + | * Downlink time? Julian: 15 TB / day uncompressed. With fewer bits, compression ~ 1TB/day | ||
| + | * Amy: Possible tech (implementation in ~2 yrs) Ka band, 30 GHz, 150 Mb/ | ||
| + | * 1 Tb is about 10 hrs. Likely DSN time is limited to few hours. | ||
| + | * Shaul: We may need to do some amount of onboard preprocessing. | ||
| + | | ||
| + | Readout: | ||
| + | * need wire counts and mux factor. | ||
| + | * 100 mK --> 4 K | ||
| + | * Toki: what is cooling power? | ||
| + | * Just wire count for now. lengths and materials are helpful as well. | ||
| + | * Assuming: Achieved, x68. Can also do a possible value, x105 from EBEX or similar. | ||
| + | * Berkeley development working to x300. Requires significant work still. | ||
| + | * Do in next 1-2 wks. **Karl** relay number px and band layout, etc. | ||
| + | * Power use, Roger calculating | ||
| + | |||
| + | Simulations starting (Julian) | ||
| + | * software running, was developed and used for Planck. | ||
| + | * running noise map of few detectors. | ||
| + | * Andreas Zonker running this | ||
| + | * systematics group deciding what to include | ||
| + | * sidelobes (brad doing grasp calculations) | ||
| + | * calibration and gain variations | ||
| + | * metrics such as S/N on dipole | ||
| + | * Polarization calibration a work in progress | ||
| + | |||
| + | Sun shields | ||
| + | * options to get alpha = 30. | ||
| + | * Julian: alpha of 35 optimum was for LB. should recalculate optimum for PICO | ||
| + | * deployable shields | ||
| + | * for alpha 30, need 50 cm shields | ||
| + | * really shields need to be ' | ||
| + | * ' | ||
| + | * Does this make sense? | ||
| + | * Definitely would need more thermal modeling. | ||
| + | * Amy: Make everything a tulip? | ||
| + | * Amy: Useful for Team-X. Concept is currently volume limited telescope. | ||
| + | * In same vein, if telescope is cost limited we should have a design plan for this. Could have some smaller systems prepped. | ||
| + | | ||