2022/11/13 (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 array trigger window = 4.73 - 5.93 MeV |
| Cooled to base two days ago after twenty-second 5K pumpout. | |
| Taking -82V data overnight. Trying lower NaI trigger window, targeting a different strong line in the Si (n,gamma) spectrum | |
| 1030 | MC base = 30.0 mK. Most spikes peak below 33 mK, some above 35 mK |
| 1035 | HV = -91.8 V, Vtest = -22.3 mV, Ileak = -24.5 uA, Vdet = -82 V (89%). |
| 1040 | DCRC1pA baseline = -0.771 V. Seems like it may already be elevated… |
| like last time it looks like the phonon channels are affected by helium films around 44-45 hours after cooling to base (or maybe 43). Shorter than it was in the past. | |
| 1159 | Start -82.0 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 |
| 1200 | DCRC1pA baseline = -0.759 V. Seems even more elevated… |
| Other channels also look like they have elevated baselines and there may be wiggles in the traces from helium films. | |
| 1235 | DCRC1pA baseline = -0.728 V. Seems even more elevated… Pulses look weak too. |
| 1250 | Dial HV down to 0V after stopping data series. Turn off DAQ programs. |
| 1255 | Close V6 to stop circulation. |
| 1305 | V6 is now fully closed (light is presumably off on IGH, Still pressure is rising, Condenser pressure falling). Turn off 3He pump |
| 1205 | Open V3 to let mixture from Condenser side into Still side. |
| 1450 | Close 1K Pot needle valve |
| 1450 | MC = 0.57 K |
| 1450 | Turn on Still and MC heaters to 20 mW each |
| 1455 | Fill LN2 cold trap bath |
| 1455 | MB = 28.9 % |
| 1530 | 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. |
| 1605 | MC/1KPot = 3.82/4.08 K. G1(fridge) = 717 mbar. |
| 1605 | Open V9 to release pressure into the dump. |
| 1610 | MC/1KPot = 3.24/4.04 K. Gonna start pumping out a bit earlier than usual. |
| 1615 | Check pressure in IVC: 0.01 ubar. Start pumping out IVC with turbo pump. |
| 1705 | MC/1KPot/Sorb = 3.40/4.39/5.5 K. |
| 1845 | Tower = 10.66 K. Turn off MC and Still heaters |