2022/08/28 (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 West side of lead/poly shield. |
| Third day after 2nd 5K pumpout. Had temperature spikes the last couple days but detector didn't show signs of problems with helium films yesterday. Today looks worse though. | |
| 1300 | MC base is around 31.5 mK with spikes peaking mostly below 40 mK, some as high as 65 mK. |
| 1300 | No pulses in phonon channels… |
| 1350 | Mini-IbIs on DCRC3pD - seems to be stuck in normal state |
| 1355 | Mini-IbIs on DCRC3pB - seems to be stuck in normal state |
| This is similar to the first bad signs after the last 5K pumpout. Let's warm up and pump out again. | |
| 1400 | Close V6 to stop circulation. |
| 1405 | MC/Coldplate = 31.5/164 mK, Still = 1.26 K / 1.20 mbar / 0 mW, G1/G2 = 125/131 mbar, 1K Pot = 60° / 1.62 K / 21±1 mbar, MB = ?? % |
| 1410 | Turn off 3He pump |
| 1510 | MC = 0.6 K and flat |
| 1510 | Open V3 to connect Still to Condenser. |
| 1510 | Turn on Still and MC heaters to 20 mW each |
| 1620 | Close 1K Pot needle valve |
| 1625 | Fill LN2 cold trap bath actually only a partial fill, Dewar ran empty. I'll wait till tomorrow to refill it. |
| 1640 | 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. |
| 1642 | MB = 65.1% |
| 1655 | MC/Coldplate/Still/1KPot/Sorb = 3.28/4.61/3.30/3.53/4.4 K, rising |
| 1750 | G1(fridge) = 900 mbar. Open V9 to release mixture into dump |
| 1805 | MC/1KPot/Sorb = 5.74/4.34/5.4 K |
| 1935 | MC/1KPot/Sorb = 5.87/5.91/7.4 K. Temperatures look pretty flat, probably because the helium in the IVC is anchoring them to the bath. |
| 1935 | Check pressure in IVC: 0.10 ubar. Start pumping out IVC with Scroll pump MC and 1K Pot temperatures start rising |
| 2150 | MC/1KPot/Sorb = 10.6/4.34/8.0 K |
| 2150 | Turn off MC and Still heaters |