2020/10/15 (Thursday)
- Lab in-person: Matt, Michael
- 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). |
|---|---|
| 0725 | MB = 37.5% |
| 0810 | Tower = 57.5 mK. Fairly constant at the moment, within about 0.1 mK |
| 0820 | Matt Fritts body temperature = 97.3 F |
| 0902 | Tower = 57.4 mK, QET biases = (0, 270, 325, 0)/(0, 345, 350, 370)uA |
| 0906 | Start a 60 min series at HV = +10V, drifting 0.0203 V/s, prebias 15% for 2min, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = see above&below, 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(10,0.0203) |
| Prebiasing algorithm didn't really work at this low bias… RootSequencer set prebias to 11.5V, actually lower than the targeted drift start of 12.7V. Should look into the code, see what went wrong. | |
| 0906 | Vtest = 0.23 mV shortly after drift begins. Drift appears to start at 11.7 V. 0.79% HV loss |
| 0908 | Tower = 57.6 mK, QET biases = (0, 265, 325, 0)/(0, 345, 345, 370)uA |
| 0918 | Tower = 57.8 mK, QET biases = (0, 265, 325, 0)/(0, 340, 345, 365)uA |
| 1006 | Drift ends, no apparent lag. Vtest = 0.69 mV. HV at end of drift looks like 84.7 V, indicating 0.32% HV loss |
| Looks like drift was not fast enough |
| 1000 | Michael arrives in lab. Body temp 98.4 |
|---|---|
| 1010 | Tower/MC/Coldplate = 57.8/46.6/195 mK, Still = 1.49 K / 0.120 mbar / 0 mW, G1/G2= 226/209 mbar, 1K Pot = 1.63 K / 22±2 mbar. |
| 1015 | Incomplete fill of LN2 cold trap. LN2 dewar empty. |
| 1035 | Matt enters lab |
| 1116 | Begin LHe Transfer at MB = 31.1% |
| 1148 | End LHe transfer @ MB = 90.3% |
| 1205 | Attend SCDMS group meeting |
| 1250 | Switch HV leads to negative polarity |
| 1300 | MB = 90.3% |
| 1315 | Fill LN2 cold trap bath from freshly refilled Dewar |
| 1315 | Matt and Michael leave lab |
| 1535 | Write a ROOT macro to update the QET biases based on the current Tower temperature. /home/hep/cdmssoft/scdmsDAQ/MidasDAQ/online/scripts/rootsequencer/QETbias_update.c. This macro will read the most recent Tower temperature from the log written to /chocula. The macro has the optimal-QET-bias-versus-temperature functions that I derived from IbIs for each channel. The function update_QETbiases() will read the temperature and write the appropriate QET biases to the ODB, one time. The function sequence_update_QETbiases(int duration_min, int repeat_sec) will run for a duration in minutes set by the first argument and will update at intervals in seconds set by the second argument. |
| 1545 | Tower = 61.6 mK. Has wandered up from around 58.0 mK an hour ago. |
| 1550 | Check phonon channels, relock DCRC4pB |
| 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(70,30) |
| 1603 | Vtest = -2.4 mV shortly after drift begins. Rootsequencer says drift starts at -315.6 V. 0.30% HV loss. |
| Tower temperature started around 61.8 mK and fell steadily to 59.8 mK during series. The QETbias updater increased the DCRC1pD bias from 341 to 347 uA, for example. | |
| 1704 | Vtest = -3.0 V at end of drift. HV = -425.4 V according to RootSequencer. 0.28% HV loss. |
| Drift was too slow. | |
| 1805 | Tower = 60.5 mK, looks like it's done cooling after flash. |
| 1813 | 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(70,30) |
| 1813 | Vtest = -0.6 mV shortly after drift begins. Drift starts at -108.3 V. 0.22% HV loss. |
| Tower temperature started around 60.4 mK and fell steadily to 59.8 mK during series. | |
| 1914 | Vtest = -1.2 V at end of drift. HV = -210.6 V. 0.23% HV loss. |
| This data series was not written. Logger must have been turned off. I could be that I had the pulseviewer going so that a new series was not started. | |
| 2010 | Tower = 60.3 mK, seems to be done cooling mostly |
| 2017 | 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(70,30) |
| 2017 | Vtest = -0.06 mV shortly after drift begins. Drift starts at -11.8 V. 0.20% HV loss. |
| 2025 | Temperature not very stable. Seeing lots of spiky noise triggers. Increase trigger threshold 8→16 Still pretty many noise triggers, Increase trigger threshold 16→24 |
| 2030 | Temperature rising, DCRC4 channels railed. This data is garbage. |
| 2031 | Abort series. Stop series on MIDAS page. Then stop RootSequencer. Check DCRC2qI then use changeq() to step it to 11.59 (0V) in 35 1-second steps. Set Logger/Write Data to n. |
| 2035 | Relock all the channels |
| 2040 | Double-click Create_Arduino_Bridge. Monitor on Arduino Editor browser tab indicates communication established with source mover motor. Type “help” to verify. Tower temperature spikes to 1.5 K then falls, maybe just creating the bridge? not sure. |
| 2045 | Check dwell on Arduino: 15 ms. Change dwell to 40 ms. |
| 2048 | Move source -4×46 steps with 4 minute pause after each move, mvNwait -4 240 46 This should move the source to y = -24.077 mm warm (-23.974 mm cold, after correction for differential contraction). This is well into pD territory. Total sequence should take 3hr 4min, ending at 23:52. |
| 2050 | First move only caused the Tower temperature to go up from 0.140 to 0.145 K. Seems like something must be wrong… |
| 2053 | Second move caused a heating from 0.10 to 0.12 mK. Strange. (Normal peak is 1.1 K) |
| 2057 | Third move caused a heating from 0.096 to 0.11 mK. |
| 2114 | Last three moves all cause peaks at a little over 0.10 K, falling to a little below 0.09 K between. 10× lower than normal. |
| I wonder if I correctly reset the dwell from 15 ms to 40 ms. The output shows “wr dwell = 40”. Does that mean I typed that = sign in? If so it probably didn't take. Or it may have been set to zero. Crud. | |
| 2115 | Matt Fritts body temperature = 97.6 F |
plan after this mvNwait finishes at 11:53:
- do “rd dwell”. If it's 40, then dunno what's happening - just try taking data. If 15 or 0 then:
- do mvNwait 4 15 46. This should reverse whatever was done before. Should only take 11.5 minutes (shouldn't matter, no overheating problem)
- do “wr dwell 40”
- do “mvNwait -4 240 46”
| 2400 | “rd dwell” shows 0. oops. try “mv +4”. Tower peaks a little above 80 mK, similar to the -4 step moves |
|---|---|
| 2405 | do “mvNwait +4 15 2”. Tower peaks around 96 mK. do “mvNwait +4 30 2”. Tower peaks around 102 mK. |
| 2410 | do “mvNwait +4 15 3”. Tower peaks around 119 mK. |
| 2415 | do “mvNwait +4 25 3”. Tower peaks around 115 mK. do “mvNwait +4 30 5”. Tower peaks around 125 mK. |
| 2423 | do “mvNwait +4 40 30”. Peaked around 125 mK. |
| OK, if it moved at all, it should be “undone” now. | |
| 2445 | do “wr dwell 40”. do “rd dwell”, it returns 40. OK good. |
| 2448 | Move source -4×46 steps with 4 minute pause after each move, mvNwait -4 240 46 This should move the source to y = -24.077 mm warm (-23.974 mm cold, after correction for differential contraction). This is well into pD territory. Total sequence should take 3hr 4min, ending at 3:52 am. |
| Tower peaks at 1.0 K after first move. OK good. |