| | Status: LHe in bath, Turbo pump on IVC |
| 0830 | MC/Tower = 6.8/6.9 K. IVC pumping/isolated = 2.5/25 E-6mbar. Still/ColdPlate = 7.0/10.2 K. Sorb/1KPot = 13.0/>7 K. Main bath = 26.4% |
| 0845 | Check Trap 1 after yesterday's cleaning (now at room temperature): 11.3 mbar on G1. Open to P2: 8.0 mbar. Pump out Trap 1. |
| 0900 | Return Trap 1 to LN2 cold trap Dewar and fill LN2 cold trap Dewar |
| 0905 | Isolate IVC |
| 0910 | pump GHS contents to dump. G2 reads 791.5 mbar. Let mix into Trap 1 through V13a; G2 falls to 743 mbar. |
| 0915 | Let mix into fridge through Condenser valve, V1, and Trap 1 speedivalve. |
| 0920 | G2 has fallen to 660 mbar, G1 has risen to 600 mbar. MC temperature rises, 1KPot and Sorb fall |
| 0935 | Start LHe transfer at 23.2% |
| 1020 | MC/Tower = 6.6/6.6 K. Still/ColdPlate = 5.1/9.2 K. Sorb/1KPot = 6.5/5.4 K. G1/G2 = 530/490 mbar. |
| 1045 | Cease LHe transfer (73.2%). He gas cylinder ran dry and we don't have a spare. |
| 1100 | G1/G2 increased after transfer stopped, to 640/555 mbar. |
| 1105 | Open 1KPot needle valve 45 degrees. 1KPot temperature doesn't change much, hanging at 5.2 K. This is a little worrying. |
| 1108 | Open 1KPot needle valve wide, a full turn. Still no temperature change. Return to 45 degrees. |
| 1112 | Close V13a to isolate some of the mix in the dump (G2 = 577.6 mbar). Start pumping on 1KPot. |
| 1115 | Pot falls quickly to 2K, pressure ~ 40 mbar. G1 (condensing mixture) and MC fall quickly. |
| 1120 | 1KPot = 1.71 K / 20 mbar. MC/Coldplate/Still/Sorb = 2.6/3.0/2.0/<4.0 K. G1 = 125 mbar. |
| 1125 | 1KPot a bit low, 1.61 K / 7.0 mbar. Open needle valve additional 5-10 degrees. Rises to 1.66 K / 12 mbar. |
| 1130 | G1 = 72.5 mbar. Open V13a to let more mixture into fridge. 1KPot pressure goes off scale, then begins to fall again. |
| 1135 | 1KPot pressure oscillating around 300 mbar, rather high - maybe it would be better to let mixture into fridge in little spurts. 1KPot at 1.83 K |
| 1305 | V12a now open 100% |
| 1310 | 1KPot = 1.77 K / 40 mbar. MC = 1.9 K. G1/G2 = 50 mbar. |
| 1310 | Open still line gate valve. P1 rises off scale. 1KPot pressure spikes then oscillates, temperature oscillates. G1/G2 rise by about 10 mbar then settle. Not sure why this happens… basically just allowing mix in still to expand. Settles down after a couple of minutes, G1/G2 = 55/50 mbar. |
| 1320 | Close V9 leaving 51 mbar of mixture in dump. |
| 1325 | MC/Still/Coldplate = 1.92/1.88/2.25 K, G1/G2 = 55 mbar, 1KPot = 1.77 K / 38 mbar |
| 1327 | Start circulation: open V6 to 12%. Increase V6 in steps. |
| 1335 | At V6 = 13.2% some response seen: G2 increases to 60 mbar. Still temp goes down a little faster. |
| 1325 | V6 = 13.5%, MC/Still/Coldplate = 1.71/1.63/2.01 K, G1/G2 = 120/150 mbar, 1KPot = 1.77 K / 38 mbar |
| 1355 | Open V6 to 14%, G2 rises above 250 mbar then falls. MC cooling quickly. |
| 1400 | V6 = 14%, MC(H35)/Still/Coldplate = 1.26/1.17/1.29 K, G1/G2 = 140/170 mbar, 1KPot = 1.76 K / 34 mbar. Still pressure falls to readable range. |
| 1420 | Adjusted V6 up to 15%, no significant response. Open V6 100% |
| 1425 | V6 = 100%, Still = 1.26 K / 0.26 mbar, MC/Coldplate = 0.25/0.43 K, G1/G2 = 130/140 mbar, 1KPot = 1.76 K / 36 mbar |
| 1425 | Still = 1.07 K / 0.15 mbar, MC/Coldplate = 62/170 mK, G1/G2 = 90/95 mbar, 1KPot = 1.76 K / 34 mbar |
| 1455 | Open V14 to add the rest of the mixture from the dump into circulation. MC had fallen to 32 mK then rose after opening V14. |
| 1640 | Close V14 (after meeting), with dump (P1) down to 0.19 mbar. MC got down to 29 mK even with V14 open. |
| 1645 | Still = 1.14 K / 0.11 mbar, MC/Tower/Coldplate = 28.7/43.7/168 mK, G1/G2 = 110/110 mbar, 1KPot = 1.74 K / 28 mbar |
| 1710 | Perform electrical checkout. LEDs do not read on meter in diode mode, but when trying to do so the tower temperature spikes to ~700 mK. I guess that's how it works at so low a temperature. Otherwise checkout looks fine. |
| 1725 | Fill LN2 cold trap full. |