2020/09/22 (Tuesday)
- Lab in-person: Matt
- Virtual partner: Zach
| 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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| A couple days after recooling. We can't seem to cool below around 64 mK (c/w 50 mK base earlier) and there are random occurrences of temperature excursions suggesting problems with helium films. | |
| 0905 | Tower = 63.6 mK. After last night's flash, it cooled but then spiked - but since that spike it has mostly just cooled overnight. In the last couple of hours the temperature has wandered but it's in the few 10ths of a mK range, a lot smaller than last night's excursions. |
| 0905 | Almost all the phonon channels are railed. |
| 0910 | Zap DCRC1&4 SQUIDs |
| 1015 | Check phonon channels - several had to have their QET biases increased from yesterday's new settings, presumably because the temperature is a little lower. Some were falling into s/c, one had strong oscillations. Then I noticed that now the Tower temperature is falling, so that exacerbates the issue. |
| 1020 | Tower = 62.8 mK and falling. Doesn't look quite like yesterday's temperature excursions, it's not falling as fast. Looks a little more like a DCRC thing, it's maybe out of a bad state, caused by adjusting the phonon channels, relocking etc. But hard to say, may be another helium-film random walk. |
| 1030 | Tower = 62.4 mK, settling |
| 1040 | Tower = 62.3 mK, currently flat |
| 1425 | Tower = 62.0 mK, it's been pretty flat. |
| 1425 | Complete IbIs measurements at 62.0 mK and select new QET biases appropriate to this temperature. Adjust offsets. Channels look OK. Standard DCRC1pD threshold=8 looks ok. |
| 1438 | Start a 60 min series at HV = +300V, drifting 0.0262 V/s, prebias 15% for 2min, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,240,290,0)/(0,320,290,325)uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pD threshold = 8 Use Root sequencer, function drift_sequence(300,0.0262) |
| 1438 | Tower = 62.0 mK |
| 1438 | Vtest = 10.7 mV shortly after drift begins. Drift was set to start at +313.3 V. 1.4% HV loss. |
| 1539 | Series ends, no apparent lag. Vtest = 10.7 mV. HV at end of drift should be 407.7 V according to sequence, indicating 1.0% HV loss |
| 1540 | Tower = 61.9 mK. Pretty flat for entire series. |
| later look at data shows Lag Ratio = 0.997 |
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| Something is wrong with this new +300V data. Not sure what - amplitudes look low in all channels. Whatever happened it's not permanent, later -100V data looks OK. |
| 1505 | Matt Fritts body temperature 98.1 F |
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| 1516 | MB = 59.1% |
| 1530 | Matt arrives in lab |
| 1535 | Tower/MC/Coldplate = 61.8/31.8/194 mK, Still = 1.47 K / 0.110 mbar / 0 mW, G1/G2= 178/167 mbar, 1K Pot = 1.66 K / 20±1 mbar. |
| 1540 | Fill LN2 cold trap bath |
| 1550 | Swap HV leads to negative polarity |
| 1555 | Matt leaves lab |
| 1749 | Start a 60 min series at HV = -100V, drifting 0.0280 V/s, prebias 15% for 2min, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,240,290,0)/(0,320,290,325)uA, 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(100,0.0280) |
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| 1749 | Tower = 61.9 mK |
| 1750 | Vtest = -4.2 mV shortly after drift begins. Drift appears to start at -106.1 V. 1.6% HV loss. |
| 1850 | Drift ends, no apparent lag. Vtest = -7.8 mV. HV at end of drift looks like -206.2 V, indicating 1.5% HV loss |
| 1850 | Tower = 61.7 mK |
| later look at data shows Lag Ratio = 0.996 |
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| New data looks ok - drift rate is maybe slightly low. Gain is lower, not surprising considering temperature / QET biases | |
| 2118 | 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 = (0,240,290,0)/(0,320,290,325)uA, 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(100,0.0305) |
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| 2118 | Tower = 61.7 mK |
| 2118 | Vtest = -12.4 mV shortly after drift begins. According to sequence drift started at -315.6 V. 1.6% HV loss. |
| 2218 | Drift ends, no apparent lag. Vtest = -15.9 mV. According to sequence HV at end of drift should be -425.3 V, indicating 1.5% HV loss |
| 2218 | Tower = 61.4 mK |
| later look at data shows Lag Ratio = 0.992 |
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| New data looks OK, gain is lower. | ydel looks ok (-3.0 mm looks odd - this is the first time we looked at this for -300V data |
| 2225 | Log into Arduino Editor, then double-click Arduino_Create_Bridge on desktop. Go to Monitor on editor, establish communication with board. |
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| 2230 | Do rd dwell, it says 15 ms. Set Dwell to 40 ms. Establishing communication with the source mover caused a temperature spike to 1.5 K. Then it cooled again. |
| 2240 | Tower = 120 mK |
| 2240 | Move source -4×83 steps with 4 minute pause after each move, mvNwait -4 240 83 This should move the source to y = -17.992 mm (not corrected for thermal contraction). Total sequence should take 5hr 32min, ending at 04:12 am. |
| first move spikes temperature to about 1.1 K. Later peaks at 1.1 K, minima at 0.85 K. |