2021/12/07 (Tuesday)
- Lab in-personnel: Matt, Himangshu
| Status | Beginning Run 75. Started circulation yesterday. |
|---|---|
| 1035 | MC(H35) = 29.8 mK, Still = 0.130 mbar / 0 mW, G1/G2 = 73/76 mbar. 1K Pot = 40° / 1.66 K / 50±3 mbar |
| 1155 | Tower/Goldman/MC/Coldplate = 186/53.5/29.7/178 mK, Still = 1.38 K / 0.130 mbar / 0 mW, G1/G2= 73/77 mbar, 1K Pot = 1.69 K / 50±3 mbar. MB = 28.0% |
| Yesterday I noticed Tower & Goldman thermometers rising as the fridge cooled to base - now they are down again, though Tower is a little higher than yesterday's minimum of 181 mK. Goldman is lower than yesterday, maybe it will continue to cool… | |
| 1250 | Start MIDAS and connnect DCRCs: DCRC55(1)/DCRC50(3)/DCRCx(4) → Cables 2/1/3 → Tower Faces 5/3/2. Start DAQ programs. |
| Goldman temperature spikes to 0.22 K then falls to 61.0 mK, a little elevated. Note that Goldman thermometer sometimes can't be read by LakeShore bridge. I increased voltage excitation from 6.3 to 20 uV to get it to read. |
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| 1255 | Tried turning off 15VPower on DCRC1, Goldman temperature shot up. Turned it on again. Temperature fell back to 65 mK. |
| 1315 | Set DCRC phonon settings on ODB to some default values. Then try starting a run. |
| 1320 | See some pulses in DCRC1pA - woohoo! |
| Pulse viewer seems to be locking up frequently, particularly when viewing railed channels. Maybe should try it with just one DCRC at a time. | |
| 1459 | Begin LHe transfer @ MB = 22.1% |
| 1510 | Fill LN2 cold trap bath |
| 1531 | End LHe transfer @ MB = 84.6% |
| Currently we are running the detector with only DCRC1 enabled. We'll look at phonon channels one DCRC at a time. | |
| 1625 | Try tuning SQUID on DCRC1pB. This seems to work fine. Look for a working QET bias: 300 uA works, seeing pulses! Good. |