2022/11/22 (Tuesday)
- Lab in-personnel: Zach
| 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 array trigger window = 4.73 - 5.13 MeV |
| Cooled down to base two days ago after 25th 5K pumpout. Taking 0V data overnight, SiHV-triggered with low threshold. | |
| 0950 | DCRC1pA baseline = -0.798 V |
| 1045 | MC base = 32.0 mK. Most spikes peak below 36 mK, some above 40 mK |
| 1045 | DCRC1pA baseline = -0.798 V |
| 1130 | DCRC1pA baseline = -0.790 V |
| 1155 | DCRC1pA baseline = -0.765 V. Pulses are weak and there are occasional baseline wiggles. He films have killed the phonon channels. |
| Looking at dump sizes there was a change at 8:10 am. That would be 43 hours after cooling to base - that's close to the amount of time before we lose the phonon channels in recent cycles. And yet we had apparently good baselines later than that. Could be that the variations in baseline come and go, and the problems started around 8:10. There was also an excursion in MC temperature starting around 8:20 | |
| 1205 | Close V6 to stop circulation. |
| 1220 | V6 is now fully closed (light is presumably off on IGH, Still pressure is rising, Condenser pressure falling). Turn off 3He pump |
| 1329 | MB = 29.5% |
| 1330 | Fill LN2 cold trap bath |
| 1334 | Turn off DAQ programs and unplug DCRCs1&3 |
| 1335 | Open V3 to let mixture from Condenser side into Still side. |
| 1336 | Close 1K Pot needle valve |
| 1338 | MC = 0.64 K |
| 1340 | Turn on Still and MC heaters to 20 mW each |
| 1346 | Close 1K Pot speedivalve, V4a, 4He pump inlet valve. Turn off 4He pump. Close recovery valve to 4He pump outlet. NOTE: remember to open recovery valve when the pump is turned back on. |
| 1432 | MC/1KPot = 3.88/3.84 K. G1(fridge) = 760 mbar. |
| 1432 | Open V9 to release pressure into the dump. |
| 1532 | MC/1KPot = 5.87/4.37 K |
| 1535 | Check pressure in IVC: 86 nbar |
| 1537 | Start pumping out IVC with turbo pump. |
| 1720 | Tower = 10.00 K. Turn off MC and Still heaters |