2022/11/19 (Saturday)
- 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 - 5.13 MeV |
| Cooled to base two days ago after twenty-fourth 5K pumpout. Taking Run 68-style data overnight. | |
| 1005 | MC base = 29.7 mK. Most spikes peak below 33 mK, some above 38 mK. |
| 1005 | HV = -90.4 V, Vtest = -20.3 mV, Ileak = -22.3 uA, Vdet = -81.5 V (90%). |
| 1010 | DCRC1pA baseline = -0.788 V |
| At 9:37 the dump sizes started to vary significantly from the norm. However the baseline doesn't seem to have risen, so it seems that helium films haven't affected the phonon channels yet. | |
| 1016 | Start -81.5 V PuBe data series ## min long, SiHV-triggered with 1000 initial randoms, 5 Hz in-run randoms, trigger on DCRC1pA threshold 2. Start series with the Start Button |
| 1115 | DCRC1pA baseline = -0.775 V |
| 1145 | DCRC1pA baseline = -0.776 V. Pulses seem like they may be weaker |
| Between 10:45 and 11:30 there was a rise and fall in the MC base, maybe also a sign that phonon channels are about to go | |
| 1215 | DCRC1pA baseline = -0.773 V |
| 1410 | DCRC1pA baseline = -0.756 V and there are weird wiggles, weak pulses |
| 1410 | Close V6 to stop circulation. |
| 1415 | Dial HV down to 0V |
| 1415 | V6 is now fully closed (light is presumably off on IGH, Still pressure is rising, Condenser pressure falling). Turn off 3He pump |
| 1415 | Open V3 to let mixture from Condenser side into Still side. |
| 1515 | Close 1K Pot needle valve |
| 1520 | Fill LN2 cold trap bath |
| 1520 | Turn off DAQ programs and unplug DCRCs1&3 |
| 1535 | MB = 30.8% |
| 1540 | 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. |
| 1545 | MC/1KPot = 2.54/2.13 K. G1(fridge) = 124 mbar. |
| 1620 | MC/1KPot = 3.86/3.86 K. G1(fridge) = 749 mbar. |
| 1620 | Open V9 to release pressure into the dump. |
| 1650 | MC/1KPot = 3.46/4.37 K |
| 1655 | Check pressure in IVC: 8.6 nbar |
| 1700 | Start pumping out IVC with turbo pump. |
| 1845 | Tower = 10.00 K. Turn off MC and Still heaters |
| 6.38 K | 90 minutes |
| 7.22 K | 60 minutes |
| 8.17 K | 30 minutes |
| 10.0 K | 0 minutes |