2022/10/15 (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 source behind lead wall on West side of lead/poly shield. |
| NaI scan running overnight | |
| Fourteenth 5K pumpout, turbopumping IVC overnight. | |
| 1255 | MC/Still/1KPot/Sorb = 9.15/9.45*/>7/9.9 K. MC/Still heaters = 2/2 mW. G1(fridge) = 556 mbar |
| 1255 | Turbo on IVC = 1.0 nbar. With Turbo valved out for 1 minute IVC = 12 nbar. |
| 1300 | Close IVC valves on top of fridge |
| 1300 | Turn off MC and Still heaters |
| 1308 | Begin LHe transfer @ MB = 4.7% |
| 1330 | MB = 57%. High enough to start 1K Pot. |
| 1330 | 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 = 0.48 bar on mechanical gauge. Higher than usual. |
| 1335 | Pump out 1K Pot in stages. Normally I alternate between 1K Pot Speedivalve and V4a, opening V4a in brief spurts to keep 4He pump pressure low (below 5 mbar). This time I throttled the flow at the valve at the pump itself, opening just until the pump got louder, then waiting, then opening a little more, etc. |
| 1340 | Start pumping 1K Pot continuously |
| 1403 | End LHe transfer @ MB = 94.2% |
| 1410 | MC = 3.4 K. Dropped quickly to this point, then started cooling more slowly. |
| 1415 | MC/Still/1KPot/Sorb = 3.30/3.24*/2.96/<4.0 K. G1(fridge) = 396 mbar |
| 1420 | 1K Pot = 0° / 2.96 K / 3.0 mbar |
| 1420 | Open 1K Pot needle valve → 15°. 1K Pot → 2.52 K / 6.0 mbar |
| 1430 | Open 1K Pot needle valve → 30°. 1K Pot → 1.67 K / 7.5±0.5 mbar |
| 1500 | Open 1K Pot needle valve → 45°. 1K Pot → 1.56 K / 11±1 mbar |
| 1530 | MC = 2.07 K. G1(fridge) = 51 mbar |
| 1540 | MC kinked between 2.1 and 1.95 K (lambda point). |
| 1550 | Fill LN2 cold trap bath |
| 1905 | MC/Still = 1.68/1.72 K. G1(fridge) = 32 mbar |
| 1905 | Close V3 and V9, leaving 33 mbar mixture in dump (G2) |
| 1905 | 1K Pot = 1.57 K / 10±1 mbar |
| 1905 | Turn on 3He pump. G1(condenser) → 38 mbar. |
| 1910 | Start circulation through Trap 1. V6 → 12.6%. Condenser peaks at 197 mbar. MC(H35) → 1.45 K. Still → 1.48 K / 50 mbar |
| 1920 | V6 → 13.0%. Condenser(G1) peaks at 237 mbar. MC(H35) → 1.34 K. Still(P1) → 1.39 K / 14 mbar. |
| 1925 | V6 → 13.4%. Condenser(G1) peaks at 234 mbar. MC(H35) → 1.18 K. Still(P1) → 1.19 K / 4.5 mbar. |
| 1930 | V6 → 13.8%. Condenser(G1) peaks at 200 mbar. MC(H35) → 1.06 K. Still(P1) → 1.09 K / 2.0 mbar. |
| MC bounced around 1.05-1.07 K (Al transition) | |
| 1935 | V6 → 14.4%. Condenser(G1) peaks at 190 mbar. MC(H35) → 0.80 K. Still(P1) → 1.08 K / 1.3 mbar. |
| 1940 | V6 → 15.0%. Condenser(G1) peaks at 190 mbar. MC(H35) → 0.50 K. Still(P1) → 1.10 K / 0.75 mbar. |
| 1950 | V6 → 100.%. Condenser(G1) peaks at 177 mbar. MC(H35) → 0.11 K. Still(P1) → 1.08 K / 0.16 mbar. |
| 2005 | MC = 43 mK. Still = 1.09 K / 0.13 mbar. G1/G2 = 142/143 mbar. 1K Pot = 1.56 K / 10.5±0.5 mbar. |
| 2005 | Open V14 to pull the rest of the mixture out of the dump into circulation. Still peaks at 20 mbar, Condenser peaks at 171 mbar, MC peaks at 53 mK, then all relax again. 1K Pot unaffected. |
| 2050 | Still = 0.40 mbar. Close V14 |
| 2200 | MC = 27.8 mK. Still = 1.09 K / 0.110 mbar. G1/G2 = 120/119 mbar. 1K Pot = 1.58 K / 10±1 mbar. |