2020/09/02 (Wednesday)
- 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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| 1400 | Zach body temp = 98.2 |
| 1425 | Zach arrives at lab. |
| 1435 | Tower/MC/Coldplate = 50/31.8/177 mK, Still = 1.16 K / 0.095 mbar / 0 mW, G1/G2= 258/271 mbar, 1K Pot = 1.69 K / 50±2 mbar. |
| 1350 | MB = 60.4% |
| 1500 | Filled LN2 cold trap dewar. |
| 1505 | Zach leaves lab. |
| 1700 | Write sequence for -250V @ 45.0 mV/s with prebias. Note: this follows the pattern of drift rate for -150V and -200V - for those, the drift rate seemed too high at the beginning but then flattened out. We'll see if that pattern repeats again. HVdrift_neg250V_pre15_2min_45p0mVps_multiloop10_60min.msl |
| 1716 | Start a 60 min series at HV = -250V, drifting 0.0450 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 = 8 Use sequence HVdrift_neg250V_pre15_2min_45p0mVps_multiloop10_60min.msl |
| 1717 | Tower = 50.9 mK |
| 1717 | Vtest = -10.8 mV shortly after drift begins. Drift appears to start at -254.0 V. 1.7% HV loss. |
| 1822 | Vtest = -16.7 mV then falls, indicating drift has ended: Lag Ratio ~ 1.10, good. HV at end of drift should be 417.1 V according to sequence, indicating 1.6% HV loss. |
| 1822 | Tower = 50.9 mK |
| later look at data shows Lag Ratio = 1.09 |
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| 2205 | Write sequence for -300V @ 43.1 mV/s with prebias HVdrift_neg300V_pre15_2min_43p1mVps_multiloop10_60min.msl |
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| 2227 | Start a 60 min series at HV = -300V, drifting 0.0431 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 = 8 Use sequence HVdrift_neg300V_pre15_2min_43p1mVps_multiloop10_60min.msl |
| 2227 | Tower = 50.4 mK |
| 2228 | Vtest = -13.0 mV shortly after drift begins. According to sequence drift starts at -305.2 V. 1.7% HV loss. |
| 2333 | Vtest = -19.7 mV then falls, indicating drift has ended: Lag Ratio ~ 1.10, good. HV at end of drift should be 460.2 V according to sequence, indicating 1.7% HV loss. |
| 2333 | Tower = 50.3 mK |
| later look at data shows Lag Ratio = 1.09 |
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| Turns out that noise is significantly worse in the later, flatter part |