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Agenda

  • Operations:
    • Infrastructure
      • Discovered that recovery system check valve was installed wrong. Implications.
      • New procedure for warmup: soften main bath vacuum jacket with He gas
    • Run 58 (USD1), now finished
      • HV setup - correcting grounding, dealing with chassis short
      • Breakdown seen at about 16.5 V, both polarities
      • Processing configuration solved
      • No peaks seen in data, don't know why.
    • Future runs:
      • G106a, second HV attempt. Also phonon collection efficiency versus mu-metal shield height. Possibly test DCRC RevD with adapter board from UCB. May want to study phonon noise more.
        • Queen's people visiting lab during collab meeting, would be good to be running G106a at that time
      • 6“ contact-free (aka vacuum interface)
      • Sidewall source ?
      • Theoretically, GeHV prototype test in September.
      • Consider short G106a, then 6”, then G106a again before collab meeting in August. Is this plausible??
  • DAQ and data pipe
    • Data storage and backup:
      • All old raw data (runs 53-56) copied to SLAC now. Procedures. Temporary backup on /data/chocula has been deleted (5.9 TB freed up).
      • Need to set up a system for copying incoming data
    • Code education - some progress on Allison and Nick's parts in understanding how to troubleshoot processing configurations.
  • Processing and Analysis
    • Progress in NSOF development for reprocessing
    • What should we plan to publish?
  • Physics
    • Low-energy NR peaks from neutron capture in Ge
      1. below are some very poorly labeled histograms, the left one is with a source with cutoff 5 MeV, the right is with true (higher energy) PuBe source
      2. blue curves are 50cm away with poly shielding between cryostat red curves are 70cm away with poly shielding
      3. 1 billion primaries thrown in all cases
      4. only NRs displayed
      5. energy scale is in MeV, the full scale is 0.0 to 2.5 keV

5 MeV Cutoff Source True PuBe Model

sim detector events approx rate capture events approx cap rate
5MeV, 70 cm 91,256 91.3 Hz 40 - 100 0.04 - 0.1 Hz
5MeV, 50 cm 476,536 476.5 Hz 700 - 1000 0.7 - 1.0 Hz
PuBe, 70 cm 140,510 140.5 Hz 75 - 150 0.075 - 0.15 Hz
PuBe, 50 cm 750,188 750.2 Hz 500 - 1000 0.5 - 1.0 Hz