2022/11/03 (Thursday)
- 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 two days ago after nineteenth 5K pumpout. As a test we waited a day at 5K with the IVC closed before cooling. | |
| Taking 0V SiHV-triggered data overnight, with DCRC4 disabled (no NaI). Main purpose is just to see when He films kill the phonon channels. | |
| 0950 | Baselines for DCRC1pA/B/D/DCRC3pA/B/D = -0.734/-0.699/-0.725/-0.702/-0.700/-0.702 V. These are definitely elevated. And pulses are weak. |
| At 5:30 am the base MC temperature rose from about 30 to about 31 mK, also a familiar sign that He films are about to kill the phonon channels. | |
| At 8:35 am the dump sizes started to change. Rather than dropping off, the increased from a pretty constant 68M to around 100M and became much less stable, falling as low as 45M sometimes. | |
| 1030 | Stop data series |
| 1030 | Close V6 to stop circulation. |
| 1036 | V6 is probably now fully closed (light is probably off on IGH, Still pressure is rising, Condenser pressure falling). Turn off 3He pump |
| 1255 | Close 1K Pot needle valve |
| 1255 | Open V3 to let mixture from Condenser side into Still side. |
| 1255 | Turn off DAQ programs and unplug DCRCs 1&3 |
| 1255 | MC = 0.65 K |
| 1255 | Turn on Still and MC heaters to 20 mW each |
| 1300 | 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. |
| 1555 | MC/1KPot = 5.59/5.91 K. G1(fridge) = 930 mbar. All flat. |
| 1555 | Open V9 to release pressure into the dump. (Should have done this earlier) |
| 1705 | MC/1KPot = 5.58/5.98 K. G1(fridge+dump) = 547 mbar. |
| 1705 | Check pressure in IVC: 0.14 ubar. Start pumping out IVC with turbo pump. |
| 2040 | Tower = 3.6 K. Turn off MC and Still heaters. Supposed to do this at 10.0 K, forgot. Hopefully it won't be too hard to cool down. |