2022/06/15 (Wednesday)
- Lab in-personnel: Matt, Anthony, Kitty, Anton
| 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. |
| 1055 | MC/Coldplate = 29.1/152 mK, Still = 1.07 K / 0.100 mbar / 0 mW, G1/G2 = 114/119 mbar, 1K Pot = 45° / 1.55 K / 8.0±0.5 mbar, MB = 43.5% |
| MC and Coldplate are both a bit elevated. There was a temperature spike yesterday at 11am and it seems it hasn't cooled all the way to base since then, possibly some issue with the SQUIDs. | |
| 1100 | Fill LN2 cold trap bath. |
| 1150 | Bring PuBe source in paraffin drum into K100 lab, set up on wood platform behind lead wall. Start NaI rate test. |
| 1155 | MIDAS crashed at some point. Restart MIDAS and restart DAQ programs. |
| 1200 | Check phonon channels. Relock most of them. But they all look OK after that, baselines around -0.8 or so as usual, despite the somewhat elevated temperature. |
| Let's take some data in the current configuration: PuBe present and boron shielding installed. | |
| 1205 | Start 0 V PuBe data series 62 min long, with 1000 initial randoms, 5 Hz in-run randoms, trigger on DCRC3pD threshold 10. Start series with the Start Button. |
| 1400 | After multiple NaI rate tests, return PuBe to storage in PAN 443 |
| NaI rate comparisons show that background rates above 3MeV are significantly lower with boron socks present. But the lowest detectors in the vertical stack, 17-20, don't show as much improvement. So we suspect that the boron socks are bunched up at the bottom and not providing as good shielding down there. | |
| 1445 | Remove lead from South wall of lead/poly shield. Find that the leftmost sock (orange) is folded over on itself at the bottom. |
| 1450 | Straighten the boron socks. |
| 1455 | Tie a string around the bottom of the boron socks, to hold them closer to the detectors on the cryostat side. |
| 1510 | Replace lead on South wall of lead/poly shield. |
| 1542 | Begin LHe transfer @ MB = 37.0% |
| 1630 | End LHe transfer @ MB = 94.9% |
| 1715 | Bring PuBe source in paraffin drum into K100 lab. Start NaI scans. We did some scans with the PuBe in the standard place (on wood platform behind lead wall) and also on the North side, with no lead brick shielding. |
|---|---|
| 1745 | Finish scans, return PuBe to storage in PAN 443 |
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