Agenda

Operations
- End of Run 64 (S1502, Si 6“ diam 1”-thick 5Q device).
  - Tower deinstalled
  - DCRC tests of the freezing readout problem:
    - recall that DCRC3(50) has had the problem, and DCRC1(55) recently developed it. DCRC4(X) had the problem in the past but it disappeared after Sten looked at it.
    - Testing with randoms. Hold time before freezing seems to scale roughly inversely with randoms rate. (Hold time is random though)
    - Experimenting with trace lengths: problem seems to disappear at most trace length settings…
      - Standard trace length is 3.2768 ms. At end of Run 64 charge had been set to 30.2768 ms
      - 30.2768 ms is a “bad” value which causes freezing. Standard trace length does not cause freezing. Other values (higher and lower) also don't cause freezing. This seen in both DCRC1 and DCRC3.
      - Update: DCRC4 shows the same behavior, gets stuck when running with “bad” charge trace length.
      - not entirely sure what the pattern is
      - Meanwhile DCRC52 arrived from Berkeley. We've given it the MIDAS name “DCRC6”. Haven't tested it yet. Also haven't retested DCRC4 with “good” and “bad” trace lengths
      - Studying how DAQ works and how DCRCs behave in telnet sessions. Still haven't reproduced freezing without MIDAS DAQ.
- Prepare Run 65, repeat of Run 64 with shorts fix (S1502, Si 6“ diam 1”-thick 5Q device).
  - need to fix detector shorts
  - DCRCs seem like they can be used - more tests to verify, continue to study freezing problem, watch for new problems.
- Plan for Run 66: 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
  - have begun process of removing mixture from pump, plan to change oil on Tuesday
  - OKed to pay to service/repair back-up He-3 pump, need to send to Oerlikon/Leybold
Processing and Analysis
- Run 64: look for lines in the shorted channels (thought I saw lines in earlier data). Would be useful to understand this more to see if our Am rates are good.
- Run 63 (Ge iZIP pathfinder)
  - need to analyze Cf data
- Run 62 (HV#4, Si)
  - n,gamma coincidence: timing improvements
- Run 61, HV#2 (Ge)
  - z-fiducialization studies
- Run 56/Run 54: see Allison's thesis! No further analyses needed that I know of
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