2020/08/25 (Tuesday)
- Lab in-person: Zach
- Virtual partner: Michael
| Setup | Run 73. DIB 1/3/4 → Stripline 43/48/41 → pi-filters 1/2/3 → Cable 3/1/2 → nothing/nothing/accessory_interposer → HV_Conn 1/3/2 → HV 1/2 → DCRCX(4)/DCRC55(1)-master; DCRC33(2) → HV control. DCRCs on overnight. Lead/poly shield erected (4 lead walls, 2 poly walls). |
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| 0658 | MB = 67.0%. We are turbo-pumping the cryostat vacuum jacket. |
| 0950 | Tower = 52.9 mK |
| 0951 | Start a 60 min series 0V, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,320,370,0)/(0,360,420,410)uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pD threshold = 12 Use sequence SimpleDataLoopNoFlash.msl |
| 1125 | Tower = 52.9 mK |
| 1131 | Start a 15 min series at HV = +100V, drifting 0.0301 V/s, prebias 15% for 2min, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,320,370,0)/(0,360,420,410)uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pD threshold = 12 Use sequence HVdrift_pos100V_pre15_2min_30p1mVps_multiloop10_15min.msl |
| 1132 | Vtest = 6.5 mV shortly after drift begins. Drift appears to start at +102.8 V. 2.4% HV loss. |
| 1148 | Vtest = 7.4 mV, HV = 129.7 V, drift ends. 2.3% HV loss. Lag ratio = 1.1ish. |
| 1148 | Tower = 53.0 mK |
| 1316 | Tower = 53.1 mK |
| 1320 | Start a 60 min series at HV = +100V, drifting 0.0301 V/s, prebias 0% for 1min, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,320,370,0)/(0,360,420,410)uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pD threshold = 12 Use sequence HVdrift_pos100V_1min_30p1mVps_multiloop10_60min.msl |
| 1320 | Vtest = 6.7 mV shortly after drift begins. Drift appears to start at +100.9 V. 2.7% HV loss. |
| 1426 | Vtest = 11.0 mV, HV = 208.6 V, drift ends. 2.1% HV loss. Lag ratio = 1.1ish. |
| 1426 | Tower = 52.9 mK |
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| 1500 | Zach body temp = 99.0 |
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| 1530 | Zach arrives at lab. |
| 1532 | Tower/MC/Coldplate = 53.3/31.8/206 mK, Still = 1.62 K / 0.10 mbar / 0 mW, G1/G2= 200/210 mbar, 1K Pot = 1.70 K / 55±5 mbar. |
| 1542 | Turbo on CVJ = 3.4 nbar. |
| 1544 | CVJ after 1min with turbo valved out = 0.14 ubar. On Aug 19 when I stopped pumping it out it was 0.30 ubar. This is may not be entirely comparable since there was no LHe in the bath then and the cryostat was around 12 K. |
| 1559 | MB = 52.6% |
| 1601 | Zach leaves lab. |
| 2100 | Zach body temp = 97.1 |
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| Currently (yellow) the main bath is boiling off more slowly than last time, but not as slowly as before the partial warmup. |
| Predicted time for Main Bath to reach 20% tomorrow: 11:14. This is better than before - if it were boiling as fast as last time, it would hit 20% at 10:14. But it's worse than before the partial warmup - at that rate it would have hit 20% at 12:05. |
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| Now it looks like the main bath is boiling off even more slowly than before the partial warmup. |
| New predicted time for Main Bath to reach 20% tomorrow: 12:03. |