2022/04/05 (Tuesday)
- Lab in-personnel: Matt
| Status | Run 76 in progress |
|---|---|
| Setup | Cable 2/1/3 → diverter/nothing/nothing → DCRC50(3)/DCRC55(1)/DCRCX(4), NaI trigger signal → DCRC52(6) |
| 0850 | Check rate of TTL signals being sent to DCRC6 from the NaI array. Count 31 pulses in 125 3.2768-ms traces, so 76±8 Bq. The scaler in the NIM crate yesterday seemed to show only 20 Bq. |
| I tried a test dataset a few days ago triggering on the NaI trigger signal and found that DCRC6 triggered properly for a few seconds then started triggering constantly. That was at ~300 Bq I think. Let's try again at a lower rate. | |
| 0900 | Start test data series, DCRC1 & DCRC6, 13 min long, no initial or in-run randoms, trigger on DCRC6pA threshold 100, baseline/sample = 16/5. PhononWaveFormLength to 8192, standard, on both DCRCs. Start series with the Start Button. |
| 0900 | Screwy trigger behavior again from DCRC6. 598 good triggers, so about 8 seconds maybe, then I don't know, maybe constant triggering. |
| 1130 | MC/Coldplate = 29.1/140 mK, Still = 1.11 K / 0.110 mbar / 0 mW, G1/G2= 200/203 mbar, 1K Pot = 18° / 1.63 K / 21±2 mbar, MB = 73.3%. |
| 1135 | Goldman = 72.0 mK @ 632 uV excitation |
| 1135 | Fill LN2 cold trap bath |
| 1250 | Prepare to move source. Source controller is powered and connected to laptop. As on March 28, restart software and run X and Y set ABSOLUTE.prg, setting the software to X=0 Y=96. |
| 1305 | Plug connectors from diverter board into source mover controller. Again notice this produces high frequency spikes in DCRC3 channels, but not the other DCRCs. |
| 1313 | Run X and Y set ABSOLUTE to X64 Y64. This should position the source on the positive y axis over pC (both sides). |
| MC rises to 0.7 K quickly, then slowly rises further. Check Goldman, looks like tower may have spiked as high as 3 K, cools to 2.4 K after a few minutes. G1/G2 rise 200→235 in a few minutes, then continue rising linearly, reaching 270 mbar in 10 minutes. Still spiked to 0.4 mbar, then after a few minutes settled around 0.2 mbar. No effect in 1K Pot. | |
| 1328 | MC/Goldman = 0.34/0.75 K and cooling. |
| 1330 | G1 (condenser) peaks at 291 mbar then starts falling. |
| 1413 | MC/Goldman = 45.6/178 mK and cooling. |
| 1443 | MC/Goldman = 41.6/162 mK and cooling. |
| 1500 | MC seems to be plateauing around 41.7 mK |
| 1510 | Check phonon channels, unlock several of them. This seems to allow more cooling, MC falling again. |
| 1513 | MC/Goldman = 37.0/98 mK and cooling. |
| 1543 | MC/Goldman = 30.6/76.7 mK and cooling. Pulses seen again. So about 2.5 hours to cool to close to base (less than 1 mK higher than before we did the move). |
| 1605 | Ugly-ass pulses in DCRC4pC. Let's zap SQUIDs. |
| 1605 | Zap SQUIDs in DCRCs 1,3,4 |
| after zap pulses look fine | |
| 1635 | Do mini-IbIs on DCRC1pA. dP/dI=1.0uV is at 172.5 mK, very close to previous 172.3 mK. So let's leave the QET biases where they are. |
| 1645 | Adjust offsets on phonon channels to get baselines around -0.85 V |
| 1646 | Start 0V data series, 63 min long, with 1000 initial randoms, no in-run randoms, trigger on DCRC1pA threshold 8. Start series with the Start Button. |