2022/10/17 (Monday)
- Lab in-personnel: Zach, Himangshu
| Status | Run 76 in progress |
|---|---|
| Setup | Cables 2/3/1 → diverter/nothing/nothing → Side2-readout HV CONN 1/3/2 → HV 1(L)/2(R) → DCRC50(3)/DCRC55(1), DCRC33(2)→HV control, NaI trigger signal → DCRCX(4) Lead/poly shield fully assembled. Boron-filled socks covering NaI detectors. PuBe source behind lead wall on West side of lead/poly shield. |
| NaI trigger window: 7.6-11.2 MeV | |
| Cooled to base two days ago after fourteenth 5K pumpout. | |
| 0930 | Since DCRC1 channels are railed, try powercycling DCRC1. Still railed. Note - MC temperature is elevated, DCRC is in a bad state probably. MC was 27.8 mK base earlier, has been at 33.5 mK overnight. |
| 0940 | Unplug both DCRC1&3. Reseat DCRC1 connection to HV box. |
| 0945 | Plug both DCRCs back in and try again. DCRC1 looks ok. DCRC3 has a couple channels I can't unrail by snapping… |
| 0950 | Powercycle DCRC3 |
| 0955 | Looks like all phonon channels are working again. Also it looks like the MC temperature is coming down. |
| 1330 | MC base is around 29.8 mK now (down from when the DCRC was in a bad state). Spikes peaking mostly below 33 mK, some above 36 mK |
| 1335 | Adjust phonon offsets to get all baselines close to -0.80 V |
| 1400 | MC/Coldplate =30/150 mK, Still = 1.12 K / 0.110 mbar / 0 mW, G1/G2 = 130/119 mbar, 1K Pot = 60° / 1.58 K / 10±1 mbar, MB = 33.7% |
| 1416 | Begin LHe transfer @ MB = 32.3 % |
| 1430 | Filled LN2 cold trap dewar |
| 1520 | MC/Coldplate =29.3/149 mK, Still = 1.11 K / 0.110 mbar / 0 mW, G1/G2 = 107/99.8 mbar, 1K Pot = 60° / 1.55 K / 10±1 mbar, MB = 92.3% |
| 1539 | Dial HV up to -109.25V nominal, -107.2V actual, for 15% prebias (using RootSequencer) |
| 1546 | Dial HV down to -95V nominal, -92.9V actual |
| 1550 | HV = -92.9 V, Vtest = -22.8 mV, Ileak = -25.1 uA, Vdet = -82.9 V (89%). |
| Vdet is a little under 90% so let's tweak the HV down a tad, to -94V nominal | |
| 1550 | Dial HV down to -94V nominal, -91.9V actual |
| 1551 | HV = -91.9 V, Vtest = -21.3 mV, Ileak = -23.4 uA, Vdet = -82.5 V (90%). |
| 1600 | Start -82.6 V PuBe data series ## min long, SiHV-triggered with 1000 initial randoms, 5 Hz in-run randoms, trigger on DCRC1pA threshold 2. Start series with the Start Button |
| 1600 | HV = -91.9 V, Vtest = -21.1 mV, Ileak = -23.3 uA, Vdet = -82.6 V (90%). |
| 1605 | MC base = 29.3 mK |
| 2050 | HV = -91.8 V, Vtest = -21.2 mV, Ileak = -23.3 uA, Vdet = -82.5 V (90%). |
| 2315 | MC base started rising around 21:00. Dumps are still as big as early in the series, but I think DCRC1pA baseline is elevated. Early in the series I think it was around -0.78, now it looks like it's around -0.76. |
| 2500 | (aka 1:00 am) Now the dumps look smaller than before, DCRC1pA baseline is around -0.75 V, and pulses definitely look weak. I'll go ahead and stop the data series. |
| 2505 | (aka 1:05 am) Dial HV down to 0V |
| 2505 | MC base 30 mK, most spikes peaking below 33 mK, some above 35 mK |
| 2510 | Close V6 to stop circulation |
| 2515 | Turn off 3He pump |