2022/09/14 (Wednesday)
- Lab in-personnel: Zach
| 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 behind lead wall on West side of lead/poly shield. |
| NaI trigger window: 7.6-11.2 MeV | |
| Cooled to base on Monday, Sixth 5K pumpout. Taking +100V NaI-triggered data overnight | |
| Temperature spikes become worse overnight | |
| 0957 | Previous data run wont stop? Stop DCRC programs, does nothing. Cant log into cdms1, I think because I (Zach) lost permissions |
| 1120 | Matt was able to log into cdms1. Killed and restarted MIDAS. Stopped the data series. |
| 1124 | HV = 97.8 V, Vtest = 15.5 mV, Ileak = 17.1 uA, Vdet = 91 V (93%). |
| 1130 | Pulses look ok |
| 1133 | Start +97.8 V PuBe data series 43 min long, SiHV-triggered, with 1000 initial randoms, 5 Hz in-run randoms, trigger on DCRC1pB threshold 10. Start series with the Start Button |
| 1220 | Made the mistake of enabling DCRC2 for a second when it was on version 3.1 instead of 3.0, so bias went very high for a minute (sorry Matt) |
| 1221 | Dial HV up to +230V nominal, +228.5V actual, for 15% prebias |
| 1227 | HV = 228.5 V, Vtest = 316.2 mV, Ileak = 347.9 uA, Vdet = 89.4 V (39%). |
| Leakage very bad, not dropping at all | |
| 1228 | Dial HV down to +200V nominal, +198.4V actual |
| 1230 | HV = 198.4 V, Vtest = 245.9 mV, Ileak = 270.5 uA, Vdet = 90.2 V (45%). |
| It seems around 90V is the max we can get at the detector | |
| 1232 | Dial HV down to 0 |
| 1400 | Check phonon channels. Pulses look fine but five of the channels have very different baselines c/w before the “jolt”. Relocking restored two of them… |
| 1410 | Adjusted offsets on the remaining three to get baselines near -0.8V. One good thing - on DCRC3pA&D the offsets aren't as extreme as before. |
| Let's try nominal 115V prebias, 100V bias like yesterday, see if the leakage is the same | |
| 1414 | Dial HV up to +115V nominal, 112.9 V actual using RootSequencer |
| 1420 | HV = 112.9 V, Vtest = 16.7 mV, Ileak = 18.4 uA, Vdet = 105.6 V (93%). Seems to be better than yesterday. |
| 1421 | Dial HV down to +100V nominal, 97.9 V actual |
| 1427 | HV = 97.9 V, Vtest = 11.2 mV, Ileak = 12.3 uA, Vdet = 92.9 V (95%). Better than yesterday. |
| 1427 | Dial HV up to +150V nominal, 148.0 V actual |
| 1430 | HV = 148 V, Vtest = 124.4 mV, Ileak = 136.8 uA, Vdet = 93.3 V (63%). Vtest seems flat. Not good. |
| 1431 | Dial HV down to +130V nominal, 128.0 V actual |
| 1433 | HV = 128 V, Vtest = 78.5 mV, Ileak = 86.4 uA, Vdet = 93.5 V (73%). |
| 1434 | Dial HV down to +120V nominal, 118.1 V actual |
| 1435 | HV = 118.1 V, Vtest = 57.2 mV, Ileak = 62.9 uA, Vdet = 92.9 V (79%). |
| 1436 | Dial HV down to +115V nominal, 112.9 V actual |
| 1437 | HV = 112.9 V, Vtest = 47 mV, Ileak = 51.7 uA, Vdet = 92.2 V (82%). So there's hysteresis. Leakage was much better at this bias just 20 minutes ago. |
| 1439 | Dial HV down to +100V nominal, 97.9 V actual |
| 1441 | HV = 97.9 V, Vtest = 14.8 mV, Ileak = 16.3 uA, Vdet = 91.4 V (93%). OK finally back up above 90% (though a bit worse than earlier). Looks like +100V nominal is the highest we can go. |
| 1442 | Dial HV down to 0V |
| 1459 | MC/Coldplate = 30.6/150 mK, Still = 1.13 K / 0.075 mbar / 0 mW, G1/G2 = 134/126 mbar, 1K Pot = 45° / 1.59 K / 13±1 mbar, MB = 33.7% |
| 1510 | Begin LHe transfer @ MB = 33.6% |
| 1525 | Fill LN2 cold trap bath |
| 1550 | Ended LHe transfer @ MB = 94.0% |
| The transfer seems to have affected G1 and G2, G1 rose to 145 then fell to 120 and is now settling at 130 | |
| 1730 | Check phonon channels. They seem OK although DCRC1pA baseline has shifted (that was the one that was still good after the “jolt”). |
| 1740 | Tune all offsets to get baselines near -0.80 V. We can see if/when they start drifting. |
| 2200 | Traces still look OK. Presumably they'll be dead by morning. |
| 0430 | No pulses, elevated baselines - TESs have gone normal |