2020/08/01 (Saturday)
- Lab in-person: Zach
- Virtual partner: Matt
| 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). |
|---|---|
| 0800 | Tower = 50.7 mK |
| 0953 | After falling from about 40 mV to about 30 mV, residual HV suddenly falls to about 18 mV for some reason. |
| 1050 | Write a new sequence to drift from 5V at nominal rate 23.5 mV/s using multiple loops. HVdrift_5V_23p5mVps_multiloop_nopre_60min.msl |
| 1056 | Start a 60 min series at HV = 5V, drifting 0.0235 V/s, no prebias, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,320,390,0)/(0,360,420,440) uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR randoms, trigger on DCRC1pD threshold = 8 Use sequence HVdrift_5V_23p5mVps_multiloop_nopre_60min.msl |
| 1057 | Vtest ~ 0.3 mV shortly after start of drift |
| 1100 | Tower = 50.6 mK |
| Regular pattern seen in Vtest | |
| 1110 | Vtest ~ 1.0 mV, HV = 21.5 V, Charge/Bias = 11.0067. Lag ratio ~ 14/12 ~ 1.16 |
| 1120 | Vtest ~ 1.4 mV, HV = 32.3 V, Charge/Bias = 10.7526. Lag ratio ~ 24/20 ~ 1.21 |
| 1135 | Vtest ~ 2.1 mV, HV = 49.7 V, Charge/Bias = 10.3476. Lag ratio ~ 39/32 ~ 1.20 |
| 1200 | Vtest ~ 3.0 mV, HV = 79.1 V, Charge/Bias = 9.6699. Lag ratio ~ 64/53 = 1.20 |
| 1208 | Vtest ~ 3.2 mV. HV = 88.5 V. Drift ends. |
| Total drift time was about 72 minutes. Lag ratio = 1.20 overall. That suggests about 1.00 seconds/step. |
| 1355 | Zach body temperature = 99.3 |
|---|---|
| 1417 | Zach arrives at lab. |
| 1422 | MB = 61.4% |
| 1427 | Tower/MC/Coldplate = 51.1/32.8/192 mK, Still = 1.50 K / 0.18 mbar / 5 mW, G1/G2= 381/352 mbar, 1K Pot = 1.63 K / 24±2 mbar. |
| 1435 | Tested stepper motor control from fridge computer. Nick installed new firmware to allow a series of moves with pauses. To control motor from a browser you can follow this link and set up an account: https://create.arduino.cc/editor/flyingfeet213/083dfa23-4f45-4eaa-87c7-e62b2ff1883e/preview |
| 1450 | Swap HV leads for negative biasing. |
| 1453 | Filled LN2 cold trap bath, used entire 5L dewar but the cold trap bath didn't fill completely. |
| 1505 | Zach leaves lab |
| 1524 | Start a 60 min series at HV = 5V, drifting 0.0235 V/s, no prebias, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,320,390,0)/(0,360,420,440) uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR randoms, trigger on DCRC1pD threshold = 8 Use sequence HVdrift_5V_23p5mVps_multiloop_nopre_60min.msl |
| actually it looks like only the meter's HV leads were swapped, because HP is reading negative but Vtest on Keithley is positive. | |
| 1525 | Vtest ~ 0.25 mV shortly after start of drift |
| 1525 | Tower = 51.0 mK |
| 1605 | Zach body temperature = 98.0 |
| 1609 | Vtest ~ 1.9 mV, HV = 47.9 V, Charge/Bias = 10.3935. Lag ratio ~ 45/31 ~ 1.45. Really? That much slower? |
| This time it's laggier at the beginning, then speeds up. Not so good. | |
| 1638 | Charge/Bias = 9.6645. |
| 1643 | Charge/Bias = 9.5187. |
| 1646 | Vtest ~ 3.3 mV, HV = 88.4 V, drift ends |
| Drift took 82 minutes, overall lag ratio = 1.37. | |
| 2040 | Write new sequence, multiloops, this time switching back to 10 second steps, which will hopefully make it less susceptible to variations in DAQ speed. Try to adjust the drift rate to be a little higher than before, since the last good data looked like maybe the gain was dropping a little over time, and also to account for the expected smaller lag ratio. HVdrift_5V_22p3mVps_multiloop10_nopre_60min.msl |
| 2046 | Start a 60 min series at HV = 5V, drifting 0.0223 V/s, no prebias, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,320,390,0)/(0,360,420,440) uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR randoms, trigger on DCRC1pD threshold = 8 Use sequence HVdrift_5V_22p3mVps_multiloop10_nopre_60min.msl |
| 2047 | Vtest ~ 0.25 mV shortly after start of drift |
| 2048 | Tower = 50.8 mK |
| 2056 | Vtest ~ 0.75 mV, HV = 16.5 V. Charge/Bias = 11.1206, Lag Ratio ~ 1.09, close to expected. |
| 2106 | Vtest ~ 1.25 mV, HV = 28.6 V. Charge/Bias = 10.8375, Lag Ratio ~ 1.10 |
| 2146 | Vtest ~ 3.0 mV, HV = 77.5 V. Charge/Bias = 9.7095, Lag Ratio = 1.10 |
| 2152 | Vtest ~ 3.3 mV, HV = 84.7 V. Drift ends. |
| 2120 | MB = 51.3% |
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| This is the flattest +5V drifted data yet. Increasing the step time to 10s does not seem to have hurt things. |