| | Overnight status: Main bath full of LHe, turbo pumping the IVC. |
| 0915 | Sorb = 14.8 K, 1K Pot > 7 K, Still = 8.8 K, Cold plate = 15 K, Tower = 10.0 K, MC(Cernox) = 9.9 K, MC(H35) = 9.6 K, IVC pumping = 0.54e-6 mbar, Main bath = 75.5% |
| | MC warmed at some point yesterday, at 15 K as of 2100. Cooling since then. Sorb warmed steadily between 2100 and 0100, then plateaued. |
| 0920 | Fill LN2 cold trap Dewar |
| 0925 | IVC = 4.0e-6 mbar. Isolate IVC. |
| 0935 | V9 is open, 3He pump is on. G2 reads 789.8 mbar. Open V5, V1, V3 to pump GHS contents to dump, then close them again. G1 decreases from 4 to 0.1 mbar. |
| 0940 | Open V6 to pump still pumping line to dump. G2 doesn't change significantly. P1 decreases from 0.33 to 0.016 mbar. |
| 0945 | Open V13a to let mix into LN2 cold trap 1. G2 falls to 736 mbar. |
| 1000 | Open condenser valve, V1, cold trap 1 speedivalve to let mix into fridge (slowly through closed V12a). |
| 1015 | G2 falls to 652 mbar, G1 rises to 721 mbar. Sorb falls to 8 K, 1K Pot falls to 6.8 K, Still falls to 7.0 K. |
| 1031 | Open 1K Pot needle valve 45 degrees. 1K Pot temperature falls quickly to 4.4 K, then starts to slowly increase. G2 drops about 15 mbar then slowly increases. Sorb drops to 5 K then slowly increases. |
| 1055 | Sorb = 7.8 K, 1K Pot = 6.5 K, Still = 6.2 K, Cold plate = 14 K, Tower = 9.6 K, MC(Cernox) = 9.5 K, G2 = 650 mbar |
| 1105 | Turn on 1KPot pump (the Trivac, not the scroll pump). Open pump valve and V4a. |
| 1110 | Close V13a isolating most mix in dump. Close needle valve - we'll start the pot pumping like this and see how the pump does. |
| 1115 | Open 1K Pot speedivalve. Pressure drops quickly, temperature drops but starts to increase again right away. Open needle valve 45 degrees. |
| 1120 | 1K Pot settling at about 1.8 K / 22 mbar. G2 falls to 240 mbar, still falling. MC temperature falling. |
| 1130 | 1K Pot = 1.67 K / 9 mbar. Sorb = 4 K, flat (min?). MC(Cernox) = 2.4 K. Still/Coldplate/Tower = 2.1/3.7/2.7 K. G2 = 86 mbar |
| 1135 | Open V13a to trickle mix from dump to fridge (through closed V12a). 1K Pot increases to 1.8 K / 28 mbar. |
| 1140 | G1/G2 = 120/580 mbar, both dropping |
| 1235 | 1K Pot = 1.7 K / 20 mbar. G1/G2 = 60 / 195 mbar. MC(H35)/Tower = 1.8/1.9 K. |
| 1240 | Open V12A 100%, let mix flow freely to fridge. Very brief spike in MC temp. 1K Pot jumps to 70 mbar then falls, less than 0.1 K change in temperature |
| 1310 | 1K Pot = 1.7 K / 20 mbar, G1/G2 = 45/40 mbar. |
| 1315 | Close V6. Close V12a temporarily, then open still line gate valve. G1 rises 5 mbar for some reason. Oscillation in 1K Pot, ΔP = 10 mbar, ΔT = 0.1 K. About 5 oscillations in 4 minutes seen in the pressure, with amplitude steadily decreasing. Sort of like the mixture is sloshing back and forth. |
| 1320 | Close V9 leaving 37 mbar of mix in dump. |
| 1325 | 1K Pot = 1.7 K / 22 mbar and steady. MC(H35) = 1.78 K. Still = 1.96 K. |
| 1326 | Ready to start circulation. Open V6 to 12%. |
| 1330 | Increasing V6 in steps. At 13.3% response seen: G1/G2 rise to 50 mbar, Still falls about 0.05 K to 1.91 K. |
| 1335 | Open V6 to 14%. G1/G2 → 200 mbar, Still → 1.7 K, 1K Pot → 1.8 K / 45 mbar. |
| 1340 | P1 falls into readable range. G1/G2 start to fall, peak = 240 mbar. 1K Pot pressure peaked at 60 mbar and falling. Still/MC = 1.31/1.35 K and cooling. |
| 1350 | Some spikes in still pressure, while MC rises from 1.15 K to 1.4 K, G1/G2 rise to 380 mbar. Increase V6 to 14.5%. |
| 1400 | MC = 1.00 K. Still = 1.15 K / 3 mbar. G1/G2 = 200 mbar and falling. 1K Pot = 1.7 K / 10 mbar. |
| 1405 | Open 1K Pot needle valve additional 20 degrees. |
| 1410 | V6 = 15%, Still = 1.16 K / 2.2 mbar. G1/G2 = 175 mbar. MC = 655 mK. Cold plate = 690 mK. 1K Pot = 1.8 K / 36 mbar. |
| 1410 | V6 = 16%, Still = 1.14 K / 0.75 mbar. G1/G2 = 175 mbar. MC/Tower = 298/290 mK. Cold plate = 680 mK. 1K Pot = 1.8 K / 34 mbar. |
| | Cold plate temperature is a little concerning. It cooled a lot faster last run. When MC was where it is now, cold plate was below 500 mK. |
| 1430 | V6 = 17%, Still = 1.10 K / 0.36 mbar. G1/G2 = 140 mbar. MC/Tower = 150/150 mK. Cold plate = 555 mK. 1K Pot = 1.8 K / 34 mbar. |
| 1445 | V6 = 18%, Still = 1.09 K / 0.22 mbar. G1/G2 = 115 mbar. MC/Tower = 85/88 mK. Cold plate = 238 mK. 1K Pot = 1.8 K / 32 mbar. |
| | OK that's reassuring. Cooling seems slower than last time. Maybe it's because we're using the Trivac pot pump - it may not be as strong, so the pot level may be lower. |
| 1515 | V6 = 19.5%, Still = 1.08 K / 0.16 mbar. G1/G2 = 100 mbar. MC/Tower = 36.5/42.5 mK. Cold plate = 142 mK. 1K Pot = 1.8 K / 32 mbar. |
| 1625 | open V6 to 100%, Still = 1.04 K / 0.075 mbar. G1/G2 = 95 mbar. MC/Tower = 27.3/35.5 mK. Cold plate = 136 mK. 1K Pot = 1.8 K / 30 mbar. |
| 1635 | open V14 to pump remainder of mix from dump into fridge. |
| 1655 | close V14 with 1.2 mbar left in dump. |
| 1700 | Open valves from 1K Pot pump outlet to He recovery |
| 1705 | Fill LN2 cold trap Dewar |
| 1730 | Still = 1.06 K / 0.11 mbar. G1/G2 = 110 mbar. MC/Tower = 26.4/34.8 mK. Cold plate = 136 mK. 1K Pot = 1.8 K / 30 mbar. Main bath = 63.1%. |