Agenda

Run 70 (GeHV n,gamma NR calibration)
- Setup:
  - Replaced standard 4K heat-sinking.
  - Changed how we wire HV to the electrode to bypass SQUET
  - Modified one unused SQUET channel by shorting the TES leads. The purpose is to study noise, IbIs etc during cooling to get a better handle on the SQUID card temperature.
- Status: Warming up
- Have a few more weeks of PuBe data
- Ended with one-shot tests to look for evidence of the wirebonds going superconducting in the test channel
  - Evidence of wirebonds going in and out of superconducting
  - This means in the normal setup the Al wirebonds are too warm to superconduct. For future runs with phonon-channel-only detectors could consider anchoring Still tower stage to Coldplate stage (remove Still rod, or at least disconnect it)
- Write efficiencies have been calculated for different setups
Run 71 prep
- Motorized source mover ready to go. Need to decide on initial position and placement of copper-tape blocker
- will use 100mm iZIP G106a
- need a set of 3 SQUETs with four working phonon channels each, and two with working charge channels
SQUET recall
- Martin wants 5 of our 9 SQUETs sent back to Colorado. Should keep the best four.
  - actually Martin wants the best-performing SQUIDs, i.e. largest modulation depths. But we probably don't have that info.
- We have 2-3 months to deal with this
Analysis status:
- Run 68 (n,gamma with S101)
  - Migdal analysis
  - Yield measurement
  - Data not yet looked at:
    - Trigger study data
    - Hold-time runs at different biases done, haven't looked at them yet
    - Have reprocessed -80V Na data. Used -125V balancing factors, still need to check if those are optimal (if not we should redo it)
- Run 71
- Presentation for GEMADARC general meeting on ~~Thursday~~: Updates on Run 71 and Run 68 analysis plans
  - actually this has been delayed to Oct 3
- SiHV event reconostruction
Lab and infrastructure
- Leak detector: Pump rebuilt. Need to fill with oil and test it.
- Transferring old raw data from /cdms1 to Google shared drive. Have moved 4.6 TB so far.
- PuBe source: plan is to take over the source on our permit, house it in PAN443b, the right cleanroom. We've been storing it in the steel box there with lead, now we will use the “howitzer”.
- Sten returned DCRC55(1) a while ago. We're currently using it. We should ask him again some time if he can diagnose some of the DCRC glitches.
Future 150mm runs
- 150mm w/phonons - need to design 600mK rod to accommodate 150mm cans
- Received 4/3-inch DIBs from TAMU - now we can house either detector for phonon readout (would need to machine faces on 4/3-inch housing for DIBs)
- S1501 and S1502 sent back to TAMU
- We have decided we can run 8 phonon channels
  - Preferred DIB-pad layout: two DIBs separated by 120 degrees
  - Himangshu's mask design: PDF download
  - Will use existing vacuum-interface electrode, mounted on side opposite the phonon side
  - Will connect directly to two DCRCs, with one diverter board to route one tower wire to HV connection
  - We'll want LEDs - are there some mounted on the DIBs? We can mount external LEDs too - existing electrode has mounts.
- First 150mm phonon detector will be monolithic, but “donut+hole” arrangement (active veto) proposed as well.
- Aiming for May to finish fabrication and start run.
Other future runs
- Future HVeV runs?
  - Berkeley can help us with a Soudan-style housing mount (3“ or 4”?)
  - then use original tower, can try different heatsinking for colder SQUID card
  - would need to install optical fiber
    - through top or through stripline tube? need vacuum feedthrough
    - Look at Prisca's deuterium lamp/monochromator/filters, glass UV fiber
  - Is PuBe NR calibration feasible?
    - 1×1×0.4 cm^3 is 630× smaller than SNOLAB detector. Anthony estimates 25 events/day (over full spectrum) for Si, 250 events/day for Ge. any chance we could get multiple chips?
    - Nick's idea: sandwich between two 4“ Ge detectors for gamma coincidence (large solid angle coverage)
- Other ideas:
  - run SiHV with Nick's movable Am source (or with multiple Am sources)
  - run SiHV with no 4K heatsinking
  - re-run USD1? do we have any additional ideas to test it?
  - anything else?