2018/07/20 (Friday)
| Status: circulation and 1K Pot suspended. Mixture in dump. MC and Still heaters on at 3 mW each. Pumping out IVC with turbo pump overnight. | |
| overnight: Tower steady at 13 K, Sorb at 16K | |
| 0740 | Turn off MC and Still heaters |
| 0745 | Turbo on IVC = 2.5 nbar |
| 0810 | Open V9 and V13a to let mix in dump cool in Trap 1. Open V12a + speedivalve |
| 0815 | Fill LN2 cold trap bath |
| 0815 | Open V1 and V3 to let mixture into fridge. Condenser speedivalve and Still gate valve are open. 3He pump is off. G1/G2 → 540/530 mbar |
| 1110 | Tower/Sorb/1K Pot = 11/9.4/>7 K. Sorb is now flat, Tower falling steadily. G1/G2 = 570/525 mbar, flat. |
| 1115 | IVC = 25 nbar with Turbo valved out. Open valve to Turbo again, we'll pump IVC continuously. |
| 1120 | Start pumping on 1K Pot. Alternate between opening 1K Pot speedivalve and V4a, to not overstress pump. Pressure ~ 0.2 bar first time speedivalve opened. With both valves open, 1K Pot/Sorb → 4.8/6.2 K |
| 1125 | 1K Pot = 4.3 K / 0.65 mbar Open 1K Pot needle valve → 10°. 1K Pot → 3.4 K / 3.4 mbar Open 1K Pot needle valve → 20°. 1K Pot → 2.9 K / 6.0 mbar |
| 1130 | Open 1K Pot needle valve → 30°. 1K Pot → 2.7 K / 9.0 mbar |
| 1135 | Open 1K Pot needle valve → 40°. 1K Pot → 2.4 K / 10.0 mbar Open 1K Pot needle valve → 50°. 1K Pot → 2.4 K / 14.0 mbar |
| 1140 | Open 1K Pot needle valve → 60°. 1K Pot → 2.2 K / 17.0 mbar |
| 1140 | Tower = 10.1 K, Condenser = 472 mbar, both falling |
| 1150 | Tower = 3.4 K (fell fast). Condenser = 435 mbar 1K Pot = 2.7 K / 8 mbar. Pressure has been falling. |
| 1150 | Open 1K Pot needle valve → 70°. 1K Pot → 2.4 K / 17.0 mbar |
| 1155 | Open 1K Pot needle valve → 80°. 1K Pot → 2.2 K / 26.0 mbar |
| 1200 | Tower = 3.1 K, Condenser = 362 mbar, both falling |
| 1220 | Fill LN2 cold trap full. |
| 1230 | Tower = 2.5 K, Condenser = 142 mbar. 1K Pot = 1.9 K / 5.5 mbar. Open 1K Pot needle valve → 90°. 1K Pot → 1.6 K / 18.0 mbar |
| 1250 | Tower = 2.1 K, Condenser = 61 mbar. 1K Pot = 1.5 K / 5.0 mbar. Open 1K Pot needle valve → 100°. 1K Pot → 1.6 K / 9.0 mbar |
| 1303 | Start LHe transfer (MB = 37.5%) |
| 1315 | Tower = 1.88 K, Condenser = 49 mbar. 1K Pot = 1.4 K / 4.5 mbar. Open 1K Pot needle valve → 110°. 1K Pot → 1.5 K / 7.5 mbar |
| 1330 | Tower temperature suddenly dips from 1.85→1.75 K. Condenser pressure flattens out a bit. |
| 1335 | Tower = 1.73 K, Condenser = 38 mbar. 1K Pot = 1.4 K / 4.5 mbar. Open 1K Pot needle valve → 120°. 1K Pot → 1.6 K / 22 mbar |
| 1355 | Tower = 1.70 K and flattish, Condenser = 32 mbar and still falling. 1K Pot = 1.5 K / 6.5 mbar. |
| 1355 | End LHe transfer (MB = 89.9%) |
| 1415 | Tower = 1.67 K, Condenser = 29 mbar. 1K Pot = 1.5 K / 5.0 mbar. |
| 1420 | Turn on 3He pump. This pushes mixture that's behind pump into the fridge. G2 rises a little. |
| 1430 | Tower = 1.67 K, Condenser = 28 mbar. 1K Pot = 1.5 K / 5.0 mbar. Open 1K Pot needle valve → 130°. 1K Pot → 1.6 K / 16 mbar |
| 1430 | Close V9, leaving 33 mbar of mixture in dump. Close V3. |
| 1435 | Start circulation through Trap 1. V6 → 12.8%. Condenser peaks at 75 mbar. Tower falls to 1.6 K. |
| 1440 | V6 → 13.2%. Condenser peaks at 108 mbar. Tower → 1.51 K |
| 1450 | Tower temperature is actually rising slowly, 1.5→1.52 K |
| 1440 | V6 → 13.6%. Condenser peaks at 220 mbar. Still → 40 mbar. Tower → 1.41 K |
| 1505 | V6 → 14.0%. Condenser peaks at 280 mbar. Still → 3.4 mbar. Tower → 1.06 K |
| 1515 | V6 → 14.4%. Condenser continues to fall. Still → 1.8 mbar. Tower → 0.82 K |
| 1520 | V6 → 15.0%. Condenser peaks at 166 mbar. Still → 0.75 mbar. Tower → 0.34 K |
| 1535 | V6 → 100% |
| 1555 | Tower = 42.4 mK, Condenser = 122 mbar and falling, Still = 0.065 mbar, 1K Pot = 1.47 K / 5.5 mbar |
| 1625 | Tower = 31.0 mK, Condenser = 106 mbar, Still = 0.060 mbar, 1K Pot = 1.48 K / 5.5 mbar |
| 1625 | Open V14 to pull the rest of the mixture into circulation. Still peaks at 16 mbar then falls. Condenser peaked at 145 mbar then fell, Tower peaked at 51 mK then fell, then bounced up a bit to 33 mK |
| 1650 | Fill LN2 cold trap bath |
| 1650 | Still = 0.7 mbar, low enough: close V14 |
| 1710 | Tower = 29.4 mK, Condenser = 113 mbar, Still = 0.070 mbar, 1K Pot = 1.48 K / 5.0 mbar |
| 1730 | Tower = 29.0 mK, Condenser = 123 mbar, Still = 0.070 mbar, 1K Pot = 1.48 K / 5.0 mbar |
| 1930 | Tower = 29.6 mK, Condenser = 118 mbar, Still = 0.060 mbar, 1K Pot = 1.47 K / 4.5 mbar |