2022/12/03 (Saturday)
- Lab in-personnel: Giulia
| 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 W side of fridge. NaI array undergoing scan, trigger threshold varies. |
| Cooled to base yesterday after twenty-ninth 5K pumpout. Temperature spikes began around 2:10 am | |
| The strange MC temperature and pressure instabilities that started yesterday continue today. They look different from the temperature spikes - they're not spiky, much more gradual. |
| Is it a precursor to a fridge blockage? | |
| 1000 | All channel baselines are around 14-16 mV lower than last night, indicating more detector cooling overnight. The weird new temperature variations don't seem to be affecting the detector. |
| 1005 | Adjust phonon offsets to get all baselines near -0.800 V |
| 1010 | Actually tuning the baselines feels a bit like a moving target this morning, like the detector is cooling at the moment relatively quickly… |
| 1155 | MC/Coldplate = 31.7/149 mK, Still = 1.11 K / 0.095 mbar / 0 mW, G1/G2 = 159/135 mbar, 1K Pot = 45° / 1.58 K / 10.0±1.0 mbar, MB = 71.0% |
| 1205 | Fill LN2 cold trap dewar |
| 1230 | Adjust offsets again. This time they were higher than before by around 10 mV. Seems like the detector temperature is maybe less stable now. |
| Let's take more data like Nov 24, when I was scanning a lot of different biases and doing low threshold SiHV triggering | |
| 1241 | Dial HV up to -52.9V nominal, -51.2V actual, for 15% prebias (using RootSequencer) |
| 1247 | Dial HV down to -46.0V nominal, -44.5V actual |
| 1255 | HV = -44.5 V, Vtest = -2 mV, Ileak = -2.2 uA, Vdet = -43.6 V (98%). |
| 1255 | Start -46.6 V PuBe data series ## min long, with 1000 initial randoms, 5 Hz in-run randoms, trigger on DCRC1pA threshold 2. Start series with the Start Button |
| 1300 | DCRC1pA baseline = -0.789 V |
| 1335 | HV = -44.5 V, Vtest = -1.5 mV, Ileak = -1.7 uA, Vdet = -43.8 V (99%). |
| 1335 | DCRC1pA baseline = -0.793 V |
| 1407 | Dial HV up to -64.4V nominal, -62.9V actual, for 15% prebias (using RootSequencer) |
| 1412 | Dial HV down to -56.0V nominal, -54.4V actual |
| 1415 | HV = -54.4 V, Vtest = -1.9 mV, Ileak = -2.1 uA, Vdet = -53.5 V (98%). |
| 1418 | Start -53.5 V PuBe data series ## min long, with 1000 initial randoms, 5 Hz in-run randoms, trigger on DCRC1pA threshold 2. Start series with the Start Button |
| 1420 | DCRC1pA baseline = -0.785 V |
| 1600 | Looks like the weird temperature and pressure fluctuations have stopped. |
| 1610 | Dial HV up to -75.9V nominal, -74.4V actual, for 15% prebias (using RootSequencer) |
| 1615 | Dial HV down to -66.0V nominal, -64.6V actual |
| 1620 | HV = -64.5 V, Vtest = -2.5 mV, Ileak = -2.7 uA, Vdet = -63.4 V (98%). |
| 1622 | Start -63.4 V PuBe data series ## min long, with 1000 initial randoms, 5 Hz in-run randoms, trigger on DCRC1pA threshold 2. Start series with the Start Button |
| 1625 | DCRC1pA baseline = -0.783 V |
| 1732 | Dial HV up to -87.4V nominal, -86.1V actual, for 15% prebias (using RootSequencer) |
| Going up about 10V at a time this is the first bias where the leakage doesn't just fall to a minimum, but rises to a new plateau after reaching a minimum. | |
| 1738 | Dial HV down to -76.0V nominal, -74.7V actual |
| 1740 | HV = -74.7 V, Vtest = -3.7 mV, Ileak = -4 uA, Vdet = -73 V (98%). |
| 1744 | Start -73.0 V PuBe data series ## min long, with 1000 initial randoms, 5 Hz in-run randoms, trigger on DCRC1pA threshold 2. Start series with the Start Button |
| 1745 | DCRC1pA baseline = -0.783 V |
| 1852 | Dial HV up to -98.9V nominal, -97.4V actual, for 15% prebias (using RootSequencer) |
| 1857 | Dial HV down to -86.0V nominal, -84.4V actual |
| After flattening for a few minutes the leakage started increasing again to a new plateau. | |
| 1905 | HV = -84.5 V, Vtest = -10.4 mV, Ileak = -11.4 uA, Vdet = -79.9 V (95%). |
| 1906 | Start -79.9 V PuBe data series ## min long, with 1000 initial randoms, 5 Hz in-run randoms, trigger on DCRC1pA threshold 2. Start series with the Start Button |
| 1910 | DCRC1pA baseline = -0.786 V |
| 2011 | Dial HV up to -110.4V nominal, -109.3V actual, for 15% prebias (using RootSequencer) |
| 2017 | Dial HV down to -96.0V nominal, -94.7V actual |
| 2020 | HV = -94.7 V, Vtest = -26.2 mV, Ileak = -28.8 uA, Vdet = -83.2 V (88%). |
| Usually I don't bother to take data with leakage this bad but we'll take more for consistency. | |
| 2025 | Start -83.2 V PuBe data series ## min long, with 1000 initial randoms, 5 Hz in-run randoms, trigger on DCRC1pA threshold 2. Start series with the Start Button |
| 2025 | DCRC1pA baseline = -0.790 V |
| 2100 | Dial HV down to 0V |
| 2305 | DCRC1pA baseline = -0.730 V |