2022/04/06 (Wednesday)
- Lab in-personnel: Matt, Scott
| Status | Run 76 in progress |
|---|---|
| Setup | Cable 2/1/3 → diverter/nothing/nothing → DCRC50(3)/DCRC55(1)/DCRCX(4), NaI trigger signal → DCRC52(6) |
| 1145 | MC/Coldplate = 28.5/140 mK, Still = 1.10 K / 0.120 mbar / 0 mW, G1/G2= 195/210 mbar, 1K Pot = 18° / 1.63 K / 21±2 mbar, MB = 38.2%. |
| 1145 | Goldman = 71.7 mK @ 632 uV excitation |
| 1150 | Fill LN2 cold trap bath |
Looked at data taken after moving the source yesterday and it looks very much like the source is now on the +x axis. (UPDATE: later realized it's the -x axis.) But we thought we moved it along the +y axis. Need to doublecheck the orientation.
Double-checking it really looks right. This is a mystery. Couple possibilities: 1) the source mover didn't move correctly. 2) the channel map in processing is somehow incorrect. (Note however that in the data everything seemed consistent, the source seemed to be in the same place with respect to Side2 versus Side1.)
| 1205 | Prepare to move source. Source controller is powered and connected to laptop, NPA_PMX software still running. No need to reset X and Y, software shows they are where we left them, X=64 Y=64 (steps). |
|---|---|
| 1210 | Plug connectors from diverter board into source mover controller. Again notice this produces high frequency junk in DCRC3 channels. |
| 1215 | Something weird is happening. Channels aren't showing pulses and MC temperature is rising a few mK. Unplug the connectors again. |
| 1220 | Zap SQUIDs on DCRCs 1,3,4 |
| 1230 | Pulses look fine now. MC fell from 32.5 to 29.7 but then started rising again for some reason… |
| 1245 | MC peaked at 30.7 mK then started falling again. |
| 1250 | MC settling at 29.9 mK, pulses still OK. |
| 1315 | Had to reboot the lab laptop, so we need to start over with the source mover software. Started the software and it remembers where the source is: still says X64, Y64. |
| 1400 | Plug connectors from diverter board into source mover controller. Again notice this produces high frequency junk in DCRC3 channels. |
| Again, something goes wrong with the detector channels, and temperature starts rising. The noise from connecting the motors apparently causes the SQUIDs to go into bad states. Well, no big deal. | |
| 1410 | Run X and Y set ABSOLUTE to X64 Y96. This should position the source back at the center. Specifically here we are leaving the X motor in the same place, and rotating the Y motor to get the source back to what should be center. |
| MC rises to 0.32 K quickly, then starts falling. Check Goldman, looks like tower may have spiked as high as 0.6 K, cools to 2.4 K after a few minutes. G1 rises 195→210 in a few minutes, then continue rising linearly, reaching 222 mbar in 10 minutes. Still spiked to 0.26 mbar, then after a few minutes settled around 0.15 mbar. No effect in 1K Pot. | |
| This is a lot less cooling than the last move. Scott says the heat produced may be a function of how long the motors are powered. This time will be proportional to the greater of the two changes in position of the motors. In yesterday's move, this was 120 degrees - today it's half that. | |
| 1425 | G1 (condenser) peaks at 223 mbar then starts falling. |
| 1440 | MC = 42.0 mK and cooling. |
| 1510 | MC = 31.5 mK and cooling. |
| 1520 | Goldman = 77.4 mK and cooling. |
| 1525 | Check pulses, seeing some ugly ones… |
| 1525 | Zap SQUIDs in DCRCs 1,3,4 |
| 1540 | Pulses look OK. After zap, MC cooled to 29.7 mK but then bounced up for some reason to 31.0 mK |
| 1550 | Start LHe transfer @ MB = 32.1% |
| 1635 | End LHe transfer @ MB = 94.3% |
| 1715 | MC = 28.6 mK, it has cooled down some. |
| 1715 | Pulses all look good, and look like they're mostly around the same baselines (between -9.0 and -8.0 V), so probably dP/dI's are similar to yesterday. |
| 1720 | Adjust offsets on phonon channels to get baselines around -0.85 V |
| 1720 | Start 0V data series, 68 min long, with 1000 initial randoms, no in-run randoms, trigger on DCRC1pA threshold 8. Start series with the Start Button. |
| 1830 | MC = 28.3 mK |