2020/10/18 (Sunday)
- Lab in-person: Ruiren
- 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. Lead/poly shield erected (4 lead walls, 2 poly walls). |
|---|---|
| 0730 | MB = 66.0% |
| 0850 | Tower = 63.5 mK. Having trouble locking some of the SQUIDs and not seeing pulses… |
| 0855 | Zap DCRC1&4 SQUIDs |
| 0900 | Ruiren temperature = 36.6C |
| 1033 | Tower/MC/Coldplate = 63.4/31.7/178 mK, Still = 1.21 K / 0.130 mbar / 0 mW, G1/G2= 239/215 mbar, 1K Pot = 1.63 K / 22±2 mbar. |
| 1030 | refill lN2 cold trap dewar |
| 1035 | swap HV leads from positive to negative |
| 1039 | Ruiren leaves lab |
| 1050 | Still having trouble keeping channels locked and seeing pulses in DCRC1pD. |
| 1050 | Zap DCRC1&4 SQUIDs |
| 1145 | Managed to get pulses back in DCRC1, after looking at SQUID modulation in DCRC1pD and adjusting offset. But now DCRC4 is out of time sync. This happened before… |
| 1150 | Stop and restart DAQ programs, being careful that DCRC2 is not reset to version 3.1 on the ODB. Now seeing pulses and DCRC4 sync is restored. |
| 1150 | but then strangely, when I reset QET biases appropriate to the current temperature, lose lock in many channels and no pulses in DCRC1pD. Relock all channels and increase QET biases, pulses are back… |
| 1215 | Can get channels working again if I set QET biases well above the optimal, but not if I set them to the optimal settings. Frustrating. |
| 1230 | In particular DCRC4pC keeps falling into s/c if I try to set the QET bias to “optimal”. |
| worth noting that for the last couple days all data series were taken at temperatures in the high 50s, 60.5 tops. Now we are around 63 mK. So maybe the optimal QET bias curves don't work as well there. | |
| 1235 | Zap DCRC1&4 SQUIDs |
| 1300 | Tower temperature rises to 92 mK over 10 minutes for some reason, then starts cooling |
| 1435 | Perform IbIs on DCRC4 channels at around 65.5 mK. The optimal QET biases (dI/dP = 0.005) for DCRC4pB/C are 277/332 uA, much higher than last time we took IbIs at around this temperature - in fact these QET biases are appropriate for a temperature around 56 mk. |
| 1535 | Finish IbIs on DCRC1 channels as well. In general the IbIs curves are behaving as if the Tower temperature is actually 7.9±1.4 mK lower than what the thermometer currently says. It's as if the current Tower temperature is 57 mK, although it is reading 65 mK. |
| 1550 | Modify QETbias Updater so that you can input an offset temperature |
| 1603 | Start a 60 min series at HV = -300V, drifting 0.0305 V/s, prebias 15% for 2min, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = set automatically to track temperature, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pD threshold = 8 Use RootSequencer.c, function drift_sequence(300,0.0305) Use QETbias_update.c, function sequence_update_QETbiases(64,30,7.9) |
| 1603 | Vtest = -2.2 mV shortly after drift begins. Rootsequencer says drift starts at -315.6 V. 0.28% HV loss. |
| Tower temperature started around 64.2 mK, rose to 65.3 mK in the first 12 minutes, then generally fell to around 63.1 mK. | |
| 1704 | Vtest = -2.5 V at end of drift. HV = -425.4 V according to RootSequencer. 0.24% HV loss. |
| 1754 | Start a 60 min series at HV = -10V, drifting 0.0220 V/s, no prebias, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = set automatically to track temperature, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pD threshold = 8 Use RootSequencer.c, function drift_sequence(10,0.0220,3600,0,0) Use QETbias_update.c, function sequence_update_QETbiases(60,30,7.9) |
| 1754 | Vtest = -0.05 mV shortly after drift begins. Drift starts at -11.1 V. 0.18% HV loss. |
| Tower temperature mostly bounced between 64.4 and 65.3 mK during series. In the last 10 minutes it fell to as low as 63.7. | |
| 1855 | Vtest = -0.32 mV at end of drift. Final HV = -90.2 V. 0.14% HV loss. |
| Drift may have been slightly too slow in this series. | |
| 1930 | MB = 48.4% |
| 1945 | Tower = 61.6 mK. Coldest it has been today. Maybe should do a quick IbIs again. |
| 2000 | IbIs on DCRC1pD suggests its temperature is 57.5 mK while Tower thermometer reads 61.15 mK. So looks like Tower thermometer is reading 3.65 mK high, not as big a discrepancy as before. This channel's discrepancy was relatively low compared to the others - we'll adopt an offset of 4.7 mK. |
| 2012 | Start a 60 min series at HV = -100V, drifting 0.0285 V/s, prebias 15% for 2min, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = set automatically to track temperature, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pD threshold = 8 Use RootSequencer.c, function drift_sequence(100,0.0285) Use QETbias_update.c, function sequence_update_QETbiases(64,30,4.7) |
|---|---|
| 2012 | Vtest = -0.52 mV shortly after drift begins. Drift starts at -108.1 V. 0.19% HV loss. |
| Tower temperature started around 61.2 mK and fell to 59.8 mK over the first 30 minutes of the series then was mostly flat for the rest. | |
| 2112 | Vtest = -0.92 V at end of drift. HV = -210.0 V. 0.18% HV loss. |
| Arduino browser tab shows no connection to Arduino, since the computer rebooted this morning | |
| 2120 | Double-click Create_Arduino_Bridge on desktop. Still don't see communication with Arduino - refresh browser page and click Monitor. Arduino says hello. At this point Tower temperature spikes to 1.8 K then falls. |
| 2125 | Do “rd dwell”: dwell is 15 ms. Do “wr dwell 40”, then check with “rd dwell”. Dwell is now 40 ms. |
| 2130 | Move source -4×100 steps with 4 minute pause after each move, mvNwait -4 240 100 This should move the source to y = -36.116 mm warm (-35.975 mm cold, after correction for differential contraction). Outer part of pD. Total sequence should take 6hr 40min, ending at 4:10 am |