2022/11/20 (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 - 5.13 MeV |
| Warmed up yesterday for twenty-fifth 5K pumpout. Turbopumping IVC overnight. | |
| 1041 | Begin LHe transfer @ MB = 5.0% |
| 1045 | Turbo on IVC = 0.74 nbar. With Turbo valved out for 1 minute IVC = 7.4 nbar. |
| 1045 | MC = 5.76 K. For some reason the MC cooled off a lot more this time than the last few times. |
| 1050 | Fill LN2 cold trap bath |
| 1055 | MB = 29.4% |
| 1055 | Turn on 4He pump. Open Recovery valve to 4He pump. Pump out line to 1K pot (speedivalve closed). Check pressure in 1K Pot (with V4a open, 4He pump inlet valve closed). 1K Pot = 0.33 bar on mechanical gauge. |
| 1100 | Pump out 1K Pot slowly, throttling the flow at the valve at the pump inlet, opening just until the pump gets louder, then waiting, then opening a little more, etc. With pump just a little loud, can see pressure go down at the mechanical gauge. When this is low, open valve a bit more. When P2 gets below 30 mbar open valve all the way. |
| 1105 | 4He pump valve open all the way. |
| 1105 | 1K Pot = 3.15 K / 3.2 mbar. G1 (fridge+dump)=411 mbar. MC = 5.68 K. |
| 1125 | 1K Pot = 2.93 K / 3.2 mbar. G1 (fridge+dump)=352 mbar. MC = 3.22 K. |
| 1135 | 1K Pot = 2.87 K / 3.2 mbar. G1 (fridge+dump)=339 mbar. MC = 3.19 K. |
| 1135 | Open 1K Pot needle valve → 15°. 1K Pot → 2.74 K / 5.0 mbar |
| 1140 | Open 1K Pot needle valve → 30°. 1K Pot → 2.59 K / 6.5 mbar |
| 1143 | End LHe transfer @ MB = 93.6% |
| 1145 | Open 1K Pot needle valve → 45°. 1K Pot → 2.37 K / 9.5 mbar |
| 1240 | MC/Still/1KPot = 2.16/1.94/1.52. G1(fridge+dump) = 60 mbar and getting flat. |
| 1245 | Close V3 and V9, leaving 57 mbar mixture in dump (G2) |
| 1245 | Turn on 3He pump. G1(condenser) → 76 mbar |
| 1245 | Start circulation through Trap 1. V6 → 12.6%. Condenser peaks at 401 mbar. MC(H35) → 1.66 K. Still → 1.60 K / 50 mbar |
| 1250 | V6 → 13.0%. Condenser(G1) peaks at 365 mbar. MC(H35) → 1.42 K. Still(P1) → 1.43 K / 9.5 mbar. |
| 1252 | V6 → 13.4%. Condenser(G1) → 315 mbar, doesn't peak. MC(H35) → 1.19 K. Still(P1) → 1.21 K / 3.6 mbar. |
| 1255 | V6 → 13.8%. Condenser(G1) → 267 mbar, doesn't peak. MC(H35) → 1.03 K. Still(P1) → 1.09 K / 1.8 mbar. |
| 1257 | V6 → 14.4%. Condenser(G1) → 232 mbar, doesn't peak. MC(H35) → 0.93 K. Still(P1) → 0.97 K / 0.6 mbar. |
| 1300 | V6 → 15.0%. Condenser(G1) → 192 mbar, doesn't peak. MC(H35) → 0.88 K. Still(P1) → 0.94 K / 0.40 mbar. |
| 1300 | 1K Pot = 1.53 K / 8.0 mbar |
| 1302 | Open 1K Pot needle valve → 60°. 1K Pot → 1.53 K / 8.0 mbar, no change really |
| 1305 | V6 → 100.%. Condenser(G1) peaks at 152 mbar. MC(H35) → 0.74 mK. Still(P1) → 0.89 K / 0.13 mbar. |
| 1310 | Open V14 to pull the rest of the mixture out of the dump into circulation. First open for several seconds then close again - Still peaks at 150 mbar, Condenser peaks at 160 mbar. Open and close again: Still peaks at 150 mbar, Condenser peaks at 168 mbar. Again: Still peaks at 160 mbar, Condenser peaks at 174 mbar. Open V14 and leave it open: Still peaks at 190 mbar, Condenser peaks at 231 mbar. |
| 1315 | MC = 0.32 K. 1K Pot = 1.57 K / 12 mbar. |
| 1315 | Plug in DCRCs 1 and 3 |
| 1335 | Still = 0.90 mbar. Close V14 |
| 1355 | MC = 40.0 mK |
| 1505 | MC = 28.8 mK |
| 2015 | Can't start a MIDAS run with DCRC1 enabled, DAQ programs crash. Will have to try powercycling it. |