Agenda

Operations
- End of Run 64 (S1502, Si 6“ diam 1”-thick 5Q device).
  - Some cryo tests - applying still heat made temperature more stable and somewhat lower. Tower/MC/Coldplate = 73.0/56.5/370 mK
  - Some neutralization info - saw reduced trigger rates (shorter files) over time. Hold time was longer at higher biases.
  - Warmed up over weekend so we can fix the shorts then start a new run. Disassemble and try to repair shorts this week.
  - DCRC issues getting worse: our best one, DCRC 55(1), recently started showing the “stuck readout” problem.
    - DCRC 50(1)(C.1): stuck readout. DCRC 33(2)(C): OK. DCRC X(4)(C.1): non-functioning charge channels, used to have stuck readout but not any more. DCRC 50(3)(C.1): stuck readout.
    - attempts to reproduce symptoms without DAQ, so we can show Sten
    - Bruno is sending us the Berkeley Rev C.1. But it sounds like it's got the same problem! Also seen in TAMU's RevC.1!
      - “I notice while doing some oscillation study that the phonon can suddenly rail when the oscillation gets bad…. Besides rebooting nothing seems to work to fix it.”
      - “Just a warning, I have some troubles time to time with the board at Berkeley. Sometimes I suddenly get a flat line on all channels and I need to reboot to get it working afterwards. I don’t have any issues when it is connected to mini-bob so it is unclear what is going on. Perhaps a power supply issue. A similar problem seem to happen with DCRC at Texas A&M (also a Rev. C.1).”
- 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
  - will change oil before next run
  - should have our back-up He-3 pump repaired, but need to determine whether we have the money
Processing and Analysis
- Run 64: look for lines in the shorted channels (thought I saw lines in earlier data)
- Run 63 (Ge iZIP pathfinder)
  - Phonon collection efficiency
  - need to analyze Cf data
- Run 62 (HV#4, Si)
  - n,gamma coincidence: timing improvements
- Run 61, HV#2 (Ge)
  - Update on phonon collection efficiency
  - 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
  - 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
  - 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