2021/03/17 (Wednesday)
- Lab in-person: Ruiren
- Virtual partner: Matt, Derek
| Status | Run 74 in progress. |
|---|---|
| Setup: DIB1/2+acc → SL 41/43 → 3.2 MHz filters → cables 2/3 → nothing/HV_diverter_board → DCRC50(3)/55(1). Kepco 0-40V supply → HV BNC. No lead/poly shield. | |
| 0900 | MB = 30.5% |
| 0945 | Tower = 90.2 mK |
| 0950 | Noise in DCRC3qI/qO/DCRC1qI/qO = 1.9/1.1/3.6/1.7 e-6 @ 10 kHz |
| 1330 | Ruiren enters lab |
| 1346 | Start 31min series of +10V/-10V data (bias applied after 1 min), with 1000 beginning randoms, trigger threshold 40/40/40/40 on DCRC3qI/qO/DCRC1qI/qO, no in-run randoms, with 1.6384 ms pulses (8192 length) and 400 us prepulse (500 length). Use sequence r74_takeandflash_dcrcbias.msl |
| Tower temperature went up when bias was applied. Pretty sure this is from the HV bias on Side2, because we saw this before when only biasing Side2 and we haven't seen it when DCRC biasing Side1 only. It rose from 90 mK to peak at 113 mK after about 10 minutes, then began to fall. So maybe the heating occurs only from when the bias is first increased. | |
| 1356 | Constantly triggering because noise is too high. Reset triggering to trigger only on DCRC1qI, since that's q4, the center channel where the source is. So trigger thresholds changed to off/off/80/off. |
| 1428 | Tower/MC/Coldplate = 205.8/54.5/191 mK, Still = 1.76 K / 0.130 mbar / 0 mW, G1/G2 = 368/335 mbar, 1K Pot = 1.68 K / 40±2 mbar. |
| 1428 | Taking temperature and pressure shortly after a flash |
| 1446 | Begin LHe transfer @ MB = 20.5% |
| 1516 | End LHe transfer |
| 1532 | MB = 73.5% |
| The 250L Dewar didn't have enough left in it for us to do a full transfer. We'll need to do another LHe transfer tomorrow. |