Telecon Notes May 9, 2018
Attendance: Amy, Shaul, Al
Notes by: Karl
Agenda
Notes
Report from workshop + Action Items
SH: p 7. From Steve Ritz, planning for decadal. NASA talking delay due to JWST delay. If no delay, white papers this year (science papers). Project papers ~ 1 year after that.
SH: p 9. PICO-S4 tension discussion. could submit a single set of CMB science papers, not advocating for particular projects at that point.
SH: when project papers called for, could also have complementarity paper.
SH: quotes on p 10.
AK: need to be a clear space case, or NASA may conclude that ground can do it all and not support CMB space resources.
Other items for the near future
Final imager configuration and sensitivity, final cryogenic assessment still pending
AT: Status. Thermal analysis wrapping up now. SPIE paper numbers likely final. Are there other noise/sensitivity issues outstanding? SH: no, just temperatures.
SH: Some temperatures have changed, so AT-SH will discuss details offline.
SH: FDM vs TDM noise ends up not making a difference. total noise difference is ~2%, which is beyond the accuracy we can expect from this study. Essentially no difference between TDM/FDM.
Requirements vs best case estimates (started here, 5/09)
SH: Artificial to set a requirement. We're foreground limited, sims don't exist (yet) to say how well we can do. So r = 1×10^-4 requirement doesn't set a real noise goal until we have full sims.
SH: for other science goals, possible route to setting requirements,
Planck was within 20% of original design. We could degrade our numbers by ~20%. But this ignores the new set of issues with TES arrays (e.g. uniformity and yield).
Suggestion: reduce our numbers by a Planck factor (20%) and add a factor for yield/uniformity.
AT: requirements must be met for flight. If ground tests put you close then costs and work grow to ensure meeting requirements. Seen past missions where requirement is factor of 2 lower.
SH: add yield too, 20% degradation may be low.
AT: cost analysis assumed 90%, so reasonable place to start. (SH: 90% seems fine)
SH: So what is the additional degradation? How about sqrt(2)? AT: 1.5 or 1.6?
AK: lay out chain of logic. show where numbers are coming from. so assumptions
SH: This goes to costers and decadal. goals slightly different. For decadal we need to show high quality science. For costers need to ensure we're not making to aggressive assumptions which drive costs.
AT: 2 stories. Science objective is X, need Y sensitivity to reach that. Prediction is A, that is below Y by some margin which is enough for …