2022/11/06 (Sunday)
- Lab in-personnel: Matt
| Status | Run 76 in progress |
|---|---|
| Setup | Cables 2/3/1 → diverter/nothing/nothing → Side2-readout HV CONN 1/3/2 → HV 1(L)/2(R) → DCRC50(3)/DCRC55(1), DCRC33(2)→HV control, NaI trigger signal → DCRCX(4) Lead/poly shield fully assembled. Boron-filled socks covering NaI detectors. PuBe behind lead wall on W side of fridge. NaI scan in progress, not set up for coincidence data |
| Cooled to base yesterday after twentieth 5K pumpout. Before cooldown IVC was closed at 5K and with mixture in dump. | |
| Temperature spikes began at about 2:20 am. | |
| Observations: when we don't leave the IVC closed for a day, temperature spikes usually start around 14 hours after cooling to base. When we left the IVC closed for 25 hours with the mixture in the fridge, spikes started around 7.5 hours after cooling to base. When we left the IVC closed for 25 hours with mixture in the dump, spikes started 10 hours after cooling to base. so, it kinda looks like there is both a leak from the dilution unit and a leak from outside the IVC. |
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| Note: Daylight Saving time ended this morning. | |
| 1352 | Begin LHe transfer @ MB = 34.9% |
| 1400 | MC/Coldplate = 27.8/145 mK, Still = 1.09 K / 0.080 mbar / 0 mW, G1/G2 = 113/121 mbar, 1K Pot = 45° / 1.57 K / 9.5±0.5 mbar |
| 1405 | Fill LN2 cold trap bath |
| 1425 | Plug in DCRCs 1&3 |
| 1430 | Check phonon channels. Relock all DCRC3 channels. After that all are close to -0.8 V baselines. |
| 1437 | End LHe transfer @ MB = 93.0% |
| 1450 | Adjust phonon offsets to get all baselines near -0.800 V |
| 1500 | MC is a bit warmer, had to adjust the offsets again. Probably makes sense to wait 30 minutes after turning on DCRCs. |
| 1500 | MC base = 29.3 mK. Most spikes peaking below 30, some above 32 mK. |
| 1540 | Phonon baselines crept up a little again, readjust offsets to get them near -0.800 V |
| 2245 | DCRC1pA/B/D/DCRC3pA/B/D baselines = -0.800/-0.796/-0.800/-0.796/-0.798/-0.796 V |
| 2320 | Start 0 V PuBe data series ## min long, SiHV-triggered with 1000 initial randoms, 5 Hz in-run randoms, trigger on DCRC1pB threshold 10. Start series with the Start Button |