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Agenda

  • Operations
    • Starting Run 68: n,gamma coincidence with S101 (aka HV#4, Si HV prototype)
      • After failing to cool to 1K, warmed up fridge and opened cryostat to look for touch - none found. Closed it again.
        • theorized that maybe it wasn't a touch, maybe a problem with 1K Pot. Last time I let He gas in pot before LN2 transfer - since the gas is not very pure, this may have been a mistake, introducing to much contamination into pot that could cause ice blockages, or fill the pot partially with ice
      • Cooled down again, fridge blockage on Saturday, warmed up and cooled down again, got rid of the blockage
      • On Wednesday discovered we again couldn't cool to 1K (even worse this time)
        • now pretty confident that we have a problem with the pot. There seems to be a blockage preventing it from filling
        • consulted with Paul Crowell, learned that we can remove the needle valve shaft. A good possibility is that the shaft o-rings are worn out, air leaks in from the top
        • warming up again to investigate the 1K Pot
      • Confirmed PuBe source is available for us through end of August, minus a day for TA training (which Kevin may be able to schedule before we need the source).
      • continue to work on determining optimal source position from sims
  • 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)
      • starting to work on impact ionization model
    • Run 65 (Si 150mm 5Q 1/2-vacuum-interface)
      • 150 mm paper submitted to NIM A. Posted to arXiv.
    • 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)