2022/12/08 (Thursday)
- 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 |
| Warmed fridge yesterday for thirty-first 5K pumpout. Turbopumping IVC overnight. | |
| 1300 | MB = 2.5% |
| 1300 | Turbo on IVC = 0.74 nbar. With Turbo valved out for 1 minute IVC = 7.4 nbar. Close IVC valves, for now. |
| We are going to do a full warmup. First: pump the mixture to the dump while the temperature is still below 10K | |
| 1315 | MC/Still/1K Pot/Sorb = 5.65/6.66/>7/9.6 K |
| 1320 | Close V13a, turn on 3He pump, open V6→13.0%. This will start pumping from the fridge (both sides) and from cold LN2 Trap 1 into the dump. (V12a+speedi, V1, V3, V9 all already open) |
| 1325 | Pumping out mixture caused a little cooling, MC/Still → 5.34/6.14 K, Sorb went down then started going up, → 11.1 K and rising. |
| 1330 | Open V6 → 30% (could have done this earlier, as soon as P1 started to fall) |
| 1338 | Close Still gate valve and V1, to pump just on LN2 Trap 1 until it's empty. |
| 1350 | Isolate LN2 Trap 1 which is now pumped out to dump (close V12a and speedivalve) |
| 1351 | Continue pumping on the fridge lines (open V1 and Still Gate Valve) |
| 1405 | Stop pumping out fridge (close V1, V3, Still Gate valve, Condenser speedivalve). G1(Dump) = 714.4 mbar |
| Barometric pressure = 30.29“ (source is https://w1.weather.gov/data/obhistory/KMSP.html.) G2 = 714.4 mbar. Corrected dump pressure = 726.9 mbar. |
Ptrue[mbar] = Pdisplay[mbar] + ( Pbar[inHg] - 29.92 ) * 33.86
| 1415 | MC = 5.51 K. Sorb = 14.1 K |
|---|---|
| 1415 | Close V6. G2 = 714.7 mbar. Corrected dump pressure = 727.2 mbar. |
| 1420 | Looking more closely, G2 was still slowly rising when I closed V6, I'm going to open V6 up again → 13% |
| 1421 | Open V6 → 30% |
| 1437 | Close V6. G2 = 715.8 mbar. Corrected dump pressure = 728.3 mbar. |
| 1445 | Isolate dump (close V9) and turn off 3He pump. |
| 1734 | Recovery = 700625.59 cuft (@ 17:34:23), 16.4 cuft/hr |
| 1745 | Quick leak checker test on IVC: 1.1e-5 mbarL/s = 11000 pbarL/s, quite high background. |
| 1750 | Switch MC thermometer from H35 to Cernox (12004) |
| 1750 | MC(Cernox)/Sorb = 5.98/14.3 K |