2022/09/03 (Saturday)
- Lab in-personnel:Giulia, 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 West side of lead/poly shield. |
| NaI trigger window: 7.6-11.2 MeV | |
| fourth 5K pumpout yesterday. Pumping IVC overnight. | |
| 1440 | MC/Coldplate = 9.53/19.6 K, Still = 14.7 K, G1/G2 = 558/502 mbar, 1K Pot = 6.99 K, MB = 68.2 % . |
| 1450 | Fill LN2 cold trap bath. |
| 1450 | Turbo on IVC = 1.4 nbar. With Turbo valved out for 1 minute IVC = 12 nbar. |
| 1450 | Close IVC valves at top of fridge. |
| 1455 | Turn on 4He pump. Open Recovery valve to 4He pump. Check pressure in 1K Pot (with V4a open, 4He pump inlet valve closed). 1K Pot = 0.19 bar on mechanical gauge. |
| 1455 | Pump out 1K Pot in stages, alternating 1K Pot Speedivalve and V4a, opening V4a in brief spurts to keep 4He pump pressure low. |
| 1500 | Start pumping 1K Pot continuously |
| 1505 | MC = 9.51 K, cooling slowly. 1K Pot = 3.64 K, cooling. Sorb = 4.3 K, cooling. |
| 1510 | 1K Pot = 3.40 K, cooling |
| 1515 | Open 1K Pot needle valve → 15°. 1K Pot → 3.17 K / 5.0 mbar |
| 1520 | Open 1K Pot needle valve → 30°. 1K Pot → 2.95 K / 9 mbar |
| 2000 | MC = 2.4 K, G1(Fridge) = 110 mbar, 1K Pot = 1.57 K / 10 mbar |
| 2000 | Turn on 3He pump |
| 2010 | Close V3 and V9, leaving 110 mbar mixture in dump |
| 2010 | Start circulation through Trap 1. V6 → 12.6%. Condenser peaks at 520 mbar. MC(H35) → 1.60 K. |
| 2015 | V6 → 13.0%. Condenser(G1) peaks at 433 mbar. MC(H35) → 1.42 K. Still(P1) → 21 mbar. |
| 2025 | V6 → 13.4%. Condenser(G1) peaks at 308 mbar. MC(H35) → 1.31 K. Still(P1) → 7 mbar. |
| 2030 | V6 → 13.8%. Condenser(G1) peaks at 316 mbar. MC(H35) → 1.23 K. Still(P1) → 4 mbar. |
| 2035 | V6 → 14.4%. Condenser(G1) peaks at 310 mbar. MC(H35) → 1.15 K. Still(P1) → 2.5 mbar. |
| 2040 | V6 → 15.0%. Condenser(G1) peaks at 322 mbar. MC(H35) → 0.80 K. Still(P1) → 2 mbar. |
| 2050 | V6 → 100%. Condenser(G1) peaks at 328 mbar. MC(H35) → 0.25 K. Still(P1) → 0.3 mbar. |
| 2055 | Open V14 to pull the remaining mixture out of the Dump and into circulation |
| Condenser peaks at 510 mbar then falls again. Still goes off-scale then falls again. MC rises from 0.13 K to 0.2 K then falls again. | |
| 2105 | 1K Pot fails, → 2.15 K, pressure falls from 17→10 mbar. Must have run dry. Probably overwhelmed it trying to condense all that mix at higher than usual temperature. Plus we only have the needle valve open to 30° G1 = 480 mbar and rising. MC reached minimum 80 mK, now rising. |
| 2120 | Still = 1.5 mbar. Close V14. |
| 2120 | Condenser = 745 mbar and rising, 1KPot = 2.7 K, MC = 95 mK. Close V6 to stop circulation. |
| 2130 | Condenser = 330 mbar and falling. 1KPot = 2.15 K and falling. MC = 1.0 K. |
| 2200 | MC = 1.47 K. 1K Pot = 1.53 K / 6.5 mbar. Condenser(G1) = 72 mbar. |
| Note: forgot to turn off DCRCs before cooling to base. |