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Agenda
- Run 69 (GeHV n,gamma NR calibration) is finished.
- Tower removed
- Want to study calibration, threshold, noise further. Superconducting and normal noise data taken
- SC noise fits hint at higher fridge temps: 07190318_1058_temp_fits.png
- Run 70 plan - modification of Run 69
- Replace standard 4K heat-sinking. Removing it seems to have increased temperatures at SQUET which would make the noise worse.
- Change how we wire HV to the electrode:
- Run 70 modification: bypass SQUET. Diverter board at stripline-SQUET connection, disconnect wires from SQUET, solder wires to diverter board to plug into unused tower face. At tower face side coax connection (unused), plug pins in and solder wire to electrode. (Also bypasses side coax)
- Lab
- Sten has returned DCRC55(1) (we've been doing OK without it though. Should ask him again in a couple weeks if he has time to look at it.)
- 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”.
- Helium recovery:
- Calculations suggest we are only collecting 17% of 4He pump exhaust.
- Purchased pump rebuild kit, pump rebuild finished. Tested pump, it's working fine.
- Run 68 (n,gamma with S101) analysis:
- Working on analysis task list
- First pass trigger efficiency:
- Simulation. 1 day of livetime acquired.
- 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)
- 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?
