2022/12/07 (Wednesday)
- Lab in-personnel: Zach
| Status | Run 76 in progress |
|---|---|
| Setup | Cables 2/3/1 → diverter/nothing/nothing → Side1-readout HV CONN 1/3/2 → HV 1(L)/2(R) → DCRC55(1)/DCRC50(3), DCRC33(2)→HV control, NaI trigger signal → DCRCX(4) Lead/poly shield fully assembled. Boron-filled socks covering NaI detectors. PuBe removed from lab. NaI trigger window to 4.73-5.13 MeV |
| Cooled to base two days ago after thirtieth 5K pumpout. | |
| 0920 | DCRC1pA baseline = -0.792 V |
| 0928 | Start -82.2 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 |
| 0930 | HV = -91.7 V, Vtest = -21.6 mV, Ileak = -23.8 uA, Vdet = -82.2 V (90%). |
| DCRC1pA pulses seem strangely weak. Is it possible I got the QET bias wrong when I reset things yesterday? | |
| 0935 | DCRC1pA baseline = -0.793 V |
| 1020 | DCRC1pA baseline = -0.793 V |
| 1030 | DCRC1pA baseline = -0.791 V and there are wiggles in the trace |
| 1110 | DCRC1pA baseline = -0.779 V, significantly elevated. Pulses look weaker in other channels. |
| about a 44 hour hold time between starting circulation and losing the phonon channels. Typical. So leaking He gas around the stripline elbow two days ago did not make things worse. | |
| 1125 | Dial HV down to 0V |
| 1128 | Fill LN2 cold trap bath |
| 1130 | Close V6 to stop circulation. |
| 1134 | V6 is now fully closed (light is off on IGH, Still pressure is rising, Condenser pressure falling). Turn off 3He pump |
| 1135 | Close 1K Pot needle valve |
| 1136 | Stop DAQ programs and unplug DCRCs 1&3 |
| 1140 | Open V3, releasing pressure from Condenser side to Still side |
| 1141 | Turn on Still and MC heaters to 20 mW each |
| 1145 | 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. |
| 1242 | MC/1KPot = 3.93/4.13 K. G1(fridge) = 801 mbar. |
| 1243 | Open V9 to release pressure into the dump. |
| 1327 | MC/1KPot = 5.80/4.38 K and flat-ish |
| 1329 | Check pressure in IVC: 86 nbar |
| 1330 | Start pumping out IVC with turbo pump. |
| 1513 | Tower = 10.00 K. Turn off MC and Still heaters |