2022/11/05 (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 scan in progress, not set up for coincidence data |
| Warmed up two days ago for twentieth 5K pumpout. Left IVC closed overnight with all mixture in dump. | |
| 1230 | Check pressure in IVC: 10 nbar. Close IVC valves again. |
| 1235 | MC/1KPot/Sorb = 5.60/>7/13.7 K. G1(condenser)=0.9 mbar, P1(still)=0.14 mbar, G2(dump+Trap1)=675 mbar. |
| 1235 | Fill LN2 cold trap bath |
| 1235 | Open V12a+speedivalve to let mixture back into fridge. MC rises from 5.6→6.1 K |
| 1240 | 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 = 0.18 bar on mechanical gauge. |
| 1240 | 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 20 mbar open valve all the way. |
| 1245 | 4He pump valve open all the way. |
| 1245 | 1K Pot = 3.31 K / 2.4 mbar. G1 (fridge+dump)=533 mbar. MC =6.04 K. |
| 1300 | 1K Pot = 3.09 K / 2.4 mbar. G1 (fridge+dump)=490 mbar. MC =5.60 K. |
| 1300 | Open 1K Pot needle valve → 15°. 1K Pot → 2.94 K / 5.0 mbar |
| 1305 | Open 1K Pot needle valve → 30°. 1K Pot → 2.69 K / 6.5 mbar |
| MC drops quickly from 5.2 → 3.4 K | |
| 1310 | Open 1K Pot needle valve → 45°. 1K Pot → 2.69 K / 9.5 mbar |
| 1315 | MB = 69.2% |
| 1315 | MC/Still/1KPot = 3.22/3.10/2.60. G1(fridge+dump) = 383 mbar and falling. |
| 1335 | MC/Still/1KPot = 2.90/2.82/2.38. G1(fridge+dump) = 275 mbar and falling. |
| MC temperature kinks a couple of times between 2.10 K and 1.97 K, lambda point apparently | |
| 1530 | MC/Still/1KPot = 1.69/1.74/1.54. G1(fridge+dump) = 33 mbar and pretty flat. |
| 1535 | Close V3 and V9, leaving 52 mbar mixture in dump (G2) |
| 1535 | Turn on 3He pump. G1(condenser) → 40 mbar |
| 1535 | Start circulation through Trap 1. V6 → 12.6%. Condenser peaks at 226 mbar. MC(H35) → 1.39 K. Still → 1.43 K / 24 mbar |
| 1540 | V6 → 13.0%. Condenser(G1) peaks at 230 mbar. MC(H35) → 1.16 K. Still(P1) → 1.19 K / 4.5 mbar. |
| 1545 | 1K Pot = 1.58 K / 12±1 mbar. |
| MC temperature kinks around 1.1 K, Al transition apparently | |
| 1545 | V6 → 13.4%. Condenser(G1) peaks at 175 mbar. MC(H35) → 0.87 K. Still(P1) → 1.13 K / 2.6 mbar. |
| 1555 | V6 → 13.8%. Condenser(G1) peaks at 165 mbar. MC(H35) → 0.55 K. Still(P1) → 1.14 K / 1.7 mbar. |
| 1600 | V6 → 14.4%. Condenser(G1) peaks at 170 mbar. MC(H35) → 0.24 K. Still(P1) → 1.16 K / 0.7 mbar. |
| 1610 | V6 → 15.0%. Condenser(G1) peaks at 160 mbar. MC(H35) → 0.20 K. Still(P1) → 1.14 K / 0.5 mbar. |
| 1615 | V6 → 100.%. Condenser(G1) peaks at 164 mbar. MC(H35) → 54 mK. Still(P1) → 1.10 K / 0.13 mbar. |
| 1630 | MC = 50.0 mK. Still = 1.10 K / 0.13 mbar. G1/G2 = 150/168 mbar. 1K Pot = 1.58 K / 9.5±0.5 mbar. |
| 1630 | Open V14 to pull the rest of the mixture out of the dump into circulation. Still peaks at 26 mbar, Condenser peaks at 185 mbar, MC peaks at 69 mK, then all relax again. 1K Pot mostly unaffected. |
| 1725 | Still = 0.30 mbar. Close V14 |
| 1745 | MC = 27.6 mK |