2018/07/03 (Tuesday)
| Setup: DIB1/3/4 → 3.2 MHz filters 2/3/1 → cable 3/1/2 → gender changer 3/?/2 → HVConn 1/3/2 → HV 1/2 → DCRC55(1)/DCRC50(3) | |
| overnight: 1K pot drifting down. At 06:45 it failed: 1K Pot fell to 1.38 K / 1.45 mbar, then Pot temperature started rising, then at 6:50 Pot temperature and circulation/still pressures began rising. | |
| 0740 | G1/G2 = 800/750 mbar, 1K Pot = 4 K. Close V6 and open V14 to stop circulation and relieve pressure. G1/G2 begin to fall. |
| 0900 | Tower = 1.57 K, Still pressure offscale / 1.5 mW, G1/G2 = 108/96 mbar, V6/V14 = closed/open, 1K Pot = 2.14 K / 1.4 mbar. MB = 35.2% |
| 0900 | Open 1K Pot needle valve about 20 degrees more. 1K Pot → 1.7 K / 70 mbar then drifts down. Condenser pressure falls. |
| 0905 | Detector bias was left at 50 V. Run script changeHV-50_0.msl to dial it down to 0 V. |
| 0905 | Turn off Still heat from 1.5 mW to 0 mW. |
| 0910 | 1K Pot pressure falls to 10 mbar then spontaneously spikes and falls again - pot goes into oscillatory mode. |
| 0930 | 1K Pot = 1.62 K / 22 mbar. G1/G2 = 60/52 mbar and flat. Tower = 1.63 K |
| 0930 | Close V14 leaving 53 mbar mixture in dump |
| 0930 | Start circulation through Trap 1. V6 → 12.8%. Condenser peaks at 110 mbar. |
| 0945 | V6 → 13.2%. Condenser peaks at 67 mbar. Tower → 1.53 K. |
| 0950 | V6 → 13.5%. Condenser peaks at 160 mbar. Tower → 1.43 K. Still falls into readable range. |
| 1000 | Fill LN2 cold trap full. |
| 1005 | V6 → 13.8%. Condenser peaks at 230 mbar. Tower → 1.28 K. Still → 12 mbar. |
| 1015 | V6 → 14.2%. Condenser peaks at 200 mbar. Tower → 0.97 K. Still → 2.4 mbar. |
| 1020 | V6 → 15.0%. Condenser peaks at 180 mbar. Tower → 0.86 K. Still → 0.75 mbar. |
| 1030 | V6 → 100%. Condenser peaks at 185 mbar. Tower → 0.42 K. Still → 0.12 mbar. |
| 1125 | Tower = 34.4 mK, G1/G2 = 118/111 mbar, Still = 0.080 mbar, all pretty flat. 1K Pot = 1.51 K / 6 mbar |
| 1125 | Open V14 to let rest of mix into circulation. Tower peaks at 115 mK, Condenser peaks at 210 mbar, then both begin to fall. |
| 1200 | Tower = 38.4 mK and falling, G1/G2 = 113/107 mbar and flat, Still = 0.5 mbar |
| 1200 | Close V14 |
| 1205 | Tower = 34.8 mK and falling, G1/G2 = 113/106 mbar and flat, Still = 0.080 mbar. 1K Pot = 1.51 K / 5.5 mbar |
| 1205 | Turn on Still heater to 1.0 mW |
| 1230 | Tower = 30.5 mK and settling, G1/G2 = 127/121 mbar , Still = 0.100 mbar / 1 mW. 1K Pot = 1.50 K / 5.5 mbar |
| 1455 | Tower = 30.6 mK, G1/G2 = 123/117 mbar , Still = 0.095 mbar / 1 mW. 1K Pot = 1.45 K / 4.0 mbar |
| 1502 | Start LHe transfer @ MB = 26.4% |
| 1544 | End LHe transfer @ MB = 91.7% |
| Transfer caused a brief spike in Tower temperature 30.6 → 32.3 mK then a significant drop → 26.8 mK but then it came back up as the transfer ended. Condenser pressure rose significantly during transfer. |
|
| 1615 | Tower = 32.1 mK, G1/G2 = 232/216 mbar , Still = 0.080 mbar / 1 mW. 1K Pot = 1.41 K / 3.8 mbar |
| 1650 | Fill LN2 cold trap bath |
| 1655 | Tower = 32.2 mK, G1/G2 = 227/209 mbar , Still = 0.080 mbar / 1 mW. 1K Pot = 1.41 K / 3.6 mbar |
| 1655 | Open 1K Pot needle valve another ~15 degrees further. Temperature spikes to 1.9 K, pressure goes off scale. |
| 1700 | Tower = 30.9 mK, G1/G2 = 262/242 mbar , Still = 0.110 mbar / 1 mW. 1K Pot = 1.72 K / 400 mbar, falling |
| 1705 | Tower has increased back to 32 mK. Since the base and condenser pressure are somewhat higher since the transfer I wonder if the temperature jolt from the transfer changed things (maybe knocking some snow loose and causing a partial blockage). |
| 1710 | Tower = 32.0 mK, G1/G2 = 279/257 mbar , Still = 0.110 mbar / 1 mW. 1K Pot = 1.67 K / 50 mbar |
| 2322 | Tower = 32.9 mK, G1/G2 = 251/230 mbar , Still = 0.050 mbar / 1 mW. 1K Pot = 1.40 K / 2.8 mbar |
| 0032 | Tower = 33.1 mK, G1/G2 = 253/231 mbar , Still = 0.050 mbar / 1 mW. 1K Pot = 1.39 K / 2.2 mbar. Open 1K Pot needle vlave +20 degrees. 1K Pot = 1.8 K and falling / >1000 mbar |
| 0042 | 1K Pot = 1.73 K / 450 mbar and falling |