Agenda

Operations
- Run 64 (S1502, Si 6“ diam 1”-thick 5Q device).
  - Cooldown went well, tower base ~ 70 mK, MC 60 mK, cold plate warmer & still colder than with 600mK rod. (Could be interesting to try warming the still.)
  - First pulses seen, 0 bias - and there is no ringing like there was in Run 60 with flex side coaxes
  - All 5 channels seem to work. But three of them may be shorted, according to electrical checks during cooling…
    - Shorts seen during stack assembly between qA, qB, qE were apparently fixed, temporarily at least
    - With side coaxes in place all interchannel resistances read 13 nS at 300K (two 40 MΩ bias resistors plus small crystal resistance ~ 100 Ω)
    - During cooling, resistances to qC and qD rose - but between qA & qB & qE they stayed at 13 nS
    - First processed data seems to confirm channels are shorted. Should cut run short, fix shorts, reinstall. Probably do some short-ish tests first.
  - DCRC issues: DCRC 55(1) & 33(2) are OK. DCRC X(4) has non-functioning charge channels. DCRC 50 (3) has working charge channels but has “stuck readout” problem.
    - so may only be able to read out two of the three DIBs simultaneously.
    - note - warming issue with DCRC 33(2) - the RevC one - has been solved. Blame the SQUID-tuning GUI, I think…
- Plan for next run: re-run HV#2
  - can more channels be connected?
  - should we reduce shunt resistances?
  - should we try floating the DCRCs?
Lab infrastructure
- He-3 circulation pump somewhat noisier
  - ignoring it for this run, but should change oil before next run
  - should have our back-up He-3 pump repaired, but need to determine whether we have the money
- plans to try to improve helium recovery
  - add length of copper tubing to recovery line, to warm helium on the way to the meter. We have used it and it seems to do something. But no indication yet that it is improving recovery.
  - maybe try to recover helium while waiting for the transfer stick to cool before hookup
Processing and Analysis
- Run 63 (Ge iZIP pathfinder)
  - need to analyze bkg data (phonon collection efficiency) and Cf data
- Run 62 (HV#4, Si)
  - n,gamma coincidence: timing improvements
- Run 61, HV#2 (Ge)
  - z-fiducialization study (in progress)
- Run 56/Run 54
Old/continuing items:
- exploring ideas for improvements without upgrade: float DCRCs for symmetric biasing Proposed Scheme, decrease Rshunt in SQUETs (had a look at this, a little hard to set up: SQUET picture), sidewall sources?
- Run 62 (HV#4, Si) post-mortem: two “bad” channels seem not to be wiring problems, maybe the problem is on the detector (photos)
- Run 60, 6“ detector paper - Plan to edit and publish without 5Q data
- Lab infrastructure
  - Update on He recovery efficiency, slow transfer test
- DAQ and data pipe
  - DAQ upgrade - discussed with Bruno about IbIs tool development
  - Data storage and backup:
    - Need to copy all Run 60 and some Run 61 data to SLAC
  - Autoprocessing and data organization development:
    - currently autoprocessing suspended, no “official” processing for Runs 60, 61, 62
    - clean up database - some info missing. Consider adding additional info
- Possible plan to modify DCRCs (resistor swap) so we can increase front-end gain, improve IbIs (suggestion from Bruno)
- IF (not likely) new DCRC RevC.2 arriving from Bruce in Denver then
  - missing resistors on 3 QET channels, we've ordered some