2020/10/19 (Monday)
- Lab in-person: Matt and Ruiren
- Virtual partner: none
| 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). |
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| 0730 | MB = 30.5% |
| 0800 | This morning Tower seemed stuck around 120 mK. Zapped SQUIDs and now it is cooling again though slowly, down to 113 mK. But strangely, can see pulses in the Pulse Viewer. So there's no way the detector is this warm. Like yesterday, it seems the Tower thermometer temperature is reading much higher than the actual detector temperature. |
| 0910 | Finish IbIs on all 5 channels to find optimal QET biases. These were done at 106-117 mK according to the Tower thermometer, but the IbIs behavior suggests detector temperatures of 63-68 mK. This says there is a 45 mK offset between Tower and detector temperatures (with one outlier channel suggesting a 39 mK offset) |
| 0915 | Using a 45 mK offset to update the QET biases, channels all look OK. |
| 0932 | 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(64,30,45) |
| 0932 | Vtest = -1.8 mV shortly after drift begins. Rootsequencer says drift starts at -315.6 V. 0.23% HV loss. |
| Tower temperature ranged from 106.8 mK to 104.3 mK, generally falling throughout the series | |
| 1033 | Vtest = -2.2 V at end of drift. HV = -425.4 V according to RootSequencer. 0.21% HV loss. |
| 1107 | Start a 60 min series at HV = -10V, drifting 0.0225 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(10,0.0225,3600,0,0) Use QETbias_update.c, function sequence_update_QETbiases(60,30,45) |
| 1107 | Vtest ~ 0 mV shortly after drift begins. This may mean I started too early after last series(?). Drift starts at -11.1 V. |
| Tower temperature generally fell from 105.5 to 100.5 mK during series. | |
| 1207 | Vtest = -0.27 mV at end of drift. Final HV = -92.1 V. 0.12% HV loss. |
| 1210 | Matt Fritts body temperature = 98.0 F. Ruiren = 36 C |
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| 1330 | Matt enters lab |
| 1335 | Ruiren enters lab |
| 1335 | Tower/MC/Coldplate = 109/30.9/171 mK, Still = 1.13 K / 0.130 mbar / 0 mW, G1/G2= 241/214 mbar, 1K Pot = 1.63 K / 21±2 mbar. |
| 1440 | Start LHe transfer @ MB = 18.7% |
| 1455 | Swap HV leads to positive bias |
| 1500 | Fill LN2 cold trap bath |
| 1533 | End LHe transfer @ MB = 91.0% |
| 1600 | MB = 91.1% |
| 1615 | Matt and Ruiren exit lab |
| 1725 | Tower = 67.4 mK. It fell as low as 58 mK about 20 minutes ago, now climbing. |
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| guess I'll need to do IbIs again | |
| 1815 | Finished IbIs on 4 channels, but DCRC1pD has some ugly spikey noise, let's try a zap |
| 1815 | Zap DCRC1&4 SQUIDs |
| 1900 | Finish IbIs. Tower thermometer read 71-80 mK during the measurements but IbIs suggest detector is 56-63 mK. Tower thermometer is reading anywhere between 8-20 mK too high. The 20 value comes from the last IbIs, after the zap, and that one seems to work. |
| 1912 | Start a 60 min series at HV = 0V, 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 sequence SimpleDataLoopNoFlash.msl \\Use QETbias_update.c, function sequence_update_QETbiases(62,30,20) |
| Tower bounced between 82 and 84 mK for about 45 minutes then rose to 85 mK at the end. Not sure when the channels railed. | |
| 2004 | Most channels are railed. Abort series early. |
| 2110 | Took 7 consecutive IbIs measurements of DCRC1pD. The Tower thermometer temperature varied from 81-87 mK during the IbIs measurements but the apparent detector temperature varied much less, 59.8-60.5 mK. So the wanderings seem to have more to do with the thermometer. There does seem to be a correlation. Tdetector = 0.13*Tthermometer + 49.5 |
| 2120 | Modify QETbias Updater so that you can input a linear temperature recalibration |
| 2130 | Try to start a +300V series. But for some reason the HV doesn't seem to be changing. Or… just barely. HV falls from 0.09 to -0.13 V, when it should have increased by at least 20V. So something is wrong with the HV. Will have to check it out tomorrow. |
| We'll try another 0V series with the linear recalibration. | |
| 0934 | Start a 60 min series at HV = 0V, 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 sequence SimpleDataLoopNoFlash.msl \\Use QETbias_update.c, function sequence_update_QETbiases(62,30,0,0.13,49.5) |
| Tower thermometer wandered between 80.5 and 85.5 mK during series. The recalibration of the QETbias updater only varied the detector temperature between 60.0-60.6 mK (only a few uA variation in QET biases). |