UCSD-2019: Technical Working Group: SATs

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Charge

Generic L2 Parallel charge:

  • Identify key decisions that must be made (and justified) prior to CD-1
  • Make progress on (or actually make) those decisions,
  • Lay out a timeline and process for making each decision, consistent with the post-decision work and internal reviews that will be needed to complete preparations for CD-1,
  • Ensure that those timelines and processes are understood and supported by the collaboration, and that we (together) believe we can follow them.

Attempt at S4 SAT-specific “Goal” statement:

“In order to meet CD-1 and 3a goals by Spring 2021, the SAT group is organizing inputs for a key decision followed by review in early 2020. We anticipate this will entail a downselect between single-tube and three tube SAT cryostat options, including a definition of the interface between cryocoolers and telescope mounts, mount geometry, and configuration. Our goal for this October session is to identify the inputs we need to make a good decision in early 2020, confirm the path to getting those and the earliest possible timeline.”

Agenda

15:45 (10m) - SAT Intro, design drivers and approach (John)

15:55 (10m) - Roadmap to CD-1/3a (Besuner/Norton, already drafted by Gil)

16:05 (10m) - 3-tube vs 1-tube Matrix (Akito)

“Q: Specific budget for < 4K cryo loading, including optical loading on each < 4K stage, may be a key factor for PT/subK cooler configuration and consequently the 1-tube vs 3 tube downselect. Can we get reports of heritage S2/S3 designs, w/ loading numbers, from BK and SO, and evaluate how various choices map into cooling requirements? Nick(SO) + Jamie(BK)”

16:15 (15m) SO SAT review (N. Galitzki)

16:30 (15m) BICEP/Keck cryogenic loading and IR filter experience (Jamie B)

“Q: External Shielding may be a key factor for 1-tube vs 3-tube downselect. Do we have common agreement on design criteria for geometry trade study? Kirit K., Fred Matsuda”

16:45 (10m) SO SAT warm baffling and shielding design (Fred Matsuda)

16:55 (10m) BICEP warm baffling/shielding (Karkare)

“Q: subK cooler compatibility with mount, site, and other constraints may be a key factor in cryostat configuration decision. Do we have a clear enough idea of compatibilities and risks?: Ben S. (+ Nick)”

17:05 (10m) S4 SAT Sub-4K Coolers and Mount Interface Implications (B. L. Schmitt)

“Q: Can we be confident that magnetic/RFI shielding will be equally possible for the 3-shooter and 1-shooter designs?”

17:15 (10m total)

17:25-17:45 (20m) discussion

Remote attendance

https://lbnl.zoom.us/j/532894630

+1 669 900 6833 or +1 646 558 8656

Meeting ID: 532 894 630


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Notes

Please take notes on this live Google Doc