Agenda

Operations
- Run 68: n,gamma coincidence with S101 (aka HV#4, Si HV prototype)
  - Cryogenic status:
    - Last week, tower was warmed above 4K, then circulation restarted
    - After that achieved 30 mK with DCRCs on, better even than earlier in the run. Base stable.
    - 1K Pot not stable, requires needle valve to be opened wider on at least daily. Ran dry early Tuesday, suspended circulation remotely before pressures got too high
    - Have been attempting LHe transfers without blowing off initial gas; Tuesday transfer probably produced a thermal shock… and looks like maybe base is becoming unstable again
  - More test data taken, with PuBe source in place. Am peaks still easy to see.
    - updated noise-versus-bias, looks like 40V is optimal
    - Also took data to test neutralization hold time and the time-shifting glitch
Lab infrastructure
- He-3 circulation pumps
  - still need to send back-up He-3 pump to Oerlikon/Leybold for service/repair
Processing and Analysis
- Run 67 (re-run of USD1)
  - new work on impact ionization model:
    - https://josephss.github.io/run67/physical_model/physical_model.html
    - https://josephss.github.io/run67/physical_model_rates.html
- Run 65 (Si 150mm 5Q 1/2-vacuum-interface)
  - 150 mm paper Posted to arXiv. After revision, accepted to NIM A, working with typesetters.
- LIPs search using Run 66 GeHV data.
- Need to start Phonon Collection Efficiency paper (HV2, HV4, iZIP pathfinder)
- Run 62 (HV#4, Si)
  - planning to work on low-energy calibration, in prep for Run 67
- Run 63 (Ge iZIP pathfinder)
  - need to analyze Cf data
Old/continuing items:
- exploring ideas for improvements without upgrade: 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)
- 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)