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Agenda

  • Operations
    • Starting Run 68: n,gamma coincidence with S101 (aka HV#4, Si HV prototype)
      • Last Friday, at 77K discovered short (300 Ohm) from a QET to chassis. (also fridge blockage - but no IVC leak)
        • this channel has extra-long wirebond, and showed a short at RT if you pressed to hard on the DIB
        • attempted fix, wound up simply removing that bond (side2 channel, only need one side connected for biasing)
      • Yesterday (Wednesday), at 77K found this channel shorted AGAIN. (Higher resistance this time, 4 kOhm). (Throughput was fine, no IVC leak.)
        • warming up again. This is demoralizing.
      • Pattern with fridge blockages: if we cryoclean the same day as the LN2 transfer we're good, but if we leave it overnight and transfer first thing in the morning we get a blockage.
      • PuBe source should be available after last lab on April 30. We won't need it that soon.
      • 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)
      • Joseph has set up an external site for HTML documentation for Run 67
    • Run 65 (Si 150mm 5Q 1/2-vacuum-interface)
      • 150 mm paper submitted to NIM A. Will post to arXiv.
    • LIPs search - planning to use Run 66 data, best 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)