2022/10/24 (Monday)
- Lab in-personnel: Zach, Himangshu
| 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 source in storage in PAN 443. |
| Cooled to base two days ago after sixteenth 5K pumpout | |
| Took low-threshold -80V SiHV-triggered bg data overnight. | |
| 0955 | MC base = 29.9 mK, most spikes below 32 mK, some above 34 mK. |
| 1005 | HV = -91.7 V, Vtest = -27.5 mV, Ileak = -30.2 uA, Vdet = -79.6 V (87%). As mentioned yesterday leakage is getting worse, surely because it has been warm the last couple days and we haven't been bothering with the E-box N2 purge (it doesn't seem necessary when the humidity in the lab is low). HV = -91.7 V, Vtest = -29.8 mV, Ileak = -32.7 uA, Vdet = -78.6 V (86%) - this was the worst leakage at 9:05 am. It has gotten a little better since. |
| 1010 | DCRC1pA baseline = -0.809 V |
| 1038 | Hook up E-box N2 purge |
| 1150 | HV = -91.7 V, Vtest = -22.8 mV, Ileak = -25 uA, Vdet = -81.7 V (89%). better. |
| 1235 | Begin NaI background spectrum scan. 0-12 MeV step 0.05, 30/400/800 seconds/step for 0-6/6-8/8-12 MeV. Should end tomorrow at 12:30pm. |
| 1240 | HV = -91.7 V, Vtest = -22.3 mV, Ileak = -24.5 uA, Vdet = -81.9 V (89%). |
| 1319 | MC/Coldplate = 30/150 mK, Still = 1.13 K / 0.100 mbar / 0 mW, G1/G2 = 112/121 mbar, 1K Pot = 60° / 1.58 K / 10±1 mbar, MB = 30.4% |
| 1320 | Filled LN2 cold trap dewar |
| 1510 | HV = -91.7 V, Vtest = -21.8 mV, Ileak = -24 uA, Vdet = -82.1 V (90%). |
| 1520 | DCRC1pA baseline = -0.806 V |
| 1605 | DCRC1pA baseline = -0.805 V |
| 1625 | Dial HV down to 0V |
| 1631 | Close V6 to stop circulation. |
| 1638 | V6 is now fully closed (light is off on IGH, Still pressure is rising, Condenser pressure falling). Turn off 3He pump |
| 1640 | Close 1K Pot needle valve |
| 1642 | Open V3 to let mixture from Condenser side into Still side. |
| 1643 | MC = 0.38 K |
| 1646 | Turn on Still and MC heaters to 20 mW each |
| 1648 | Turn off DAQ programs and unplug DCRCs 1&3 |
| 1707 | 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. |
| 1714 | MC/1KPot = 2.93/3.05 K |
| 1731 | Check pressure in IVC: 0.14 ubar. Start pumping out IVC with turbo pump. Correction, this was actually 0.014 ubar I misread it, it must be low because of the new fast warmup procedure? |
| 1750 | MC/1KPot = 3.92/3.94 K. G1(fridge) = 798 mbar |
| 1805 | G1(fridge) = 840 mbar. Open V9 to release pressure into the dump. |
| 1908 | Tower = 10.16 K. Turn off MC and Still heaters. |