| 0925 | Perform mixture throughput test at MC = 77 K using above procedure with 3He pump on. Let G1 rise to 547 mbar before Step 3, then it falls to 70 mbar, then rises. Throughput = 43.2 mbar/min. A little higher than last time, 2022 March 15 |
| 0930 | Pump IVC with Leak Detector, Turbo valved out |
| 0935 | Open mixture to both sides of the fridge and cold LN2 Trap 1. |
| 0935 | IVC = 3900 pbarL/s. Why so high? |
| 0940 | Begin blowing out LN2. Main bath (G3) → 680 mbar+1atm |
| 0945 | IVC = 3870 pbarL/s, MB = 673 mbar+1atm |
| 0950 | IVC = 3830 pbarL/s, MB = 686 mbar+1atm |
| 0955 | IVC = 3810 pbarL/s, MB = 690 mbar+1atm |
| 1000 | IVC = 3790 pbarL/s, MB = 263 mbar+1atm, falling, looks like blowout is nearly over |
| 1003 | IVC = 3840 pbarL/s, MB = 186 mbar+1atm, flattening |
| 1005 | Stop LN2 blowout |
| 1015 | remove hose from MB LN2 fill pipe, remove fill pipe from cyostat and put stopper in port, for MB pumpout |
| 1015 | IVC = 3700 pbarL/s |
| 1015 | Start pumping out main bath with scroll pump. Takes 9 minutes to fall to 1 mbar. |
| 1025 | IVC = 3580 pbarL/s |
| 1030 | Pressurize MB with helium to 165 mbar above 1 atm. |
| 1030 | IVC = 3550 pbarL/s |
| 1035 | Isolate MB by closing V1a. Pump out line to the G3 volume with Scroll Pump. Isolate pump, then open 1K Pot speedivalve to check pressure: didn't see the mechanical gauge move much, P2 went off scale, probably ~ 0.02-0.05 bar. Then pump out 1K Pot (needle valve closed) with Scroll Pump to 0.030 mbar on P2. Then close 1K Pot speedivalve and V4a. Open V1a again to monitor bath pressure. |
| 1040 | IVC = 3440 pbarL/s |
| 1045 | Let 63 μbar He exchange gas into IVC. |
| 1103 | Start initial LHe transfer |
| 1110 | Turn off 3He pump, we'll leave it off like last time. |
| 1110 | MC(Cernox)/Sorb = 77.9/138.9 K, IVC = 63 μbar, G1(fridge) = 601 mbar. G3(MB) = 348 mbar+1atm |
| 1120 | MC(Cernox)/Sorb = 76.9/129.6 K, IVC = 54 μbar, G1(fridge) = 599 mbar. G3(MB) = 192 mbar+1atm |
| 1120 | The He cylinder we're using to pressurize the Dewar is about empty, switching it now. |
| 1130 | MC(Cernox)/Sorb = 74.0/116.7 K, IVC = 30 μbar, G1(fridge) = 597 mbar. G3(MB) = 445 mbar+1atm |
| 1150 | MC(Cernox)/Sorb = 61.1/70.5 K, IVC = 16 μbar, G1(fridge) = 576 mbar. G3(MB) = 359 mbar+1atm |
| 1200 | MC(Cernox)/Sorb = 55.3/42.0 K, IVC = 14 μbar, G1(fridge) = 551 mbar. G3(MB) = 338 mbar+1atm |
| 1215 | MC(Cernox)/Sorb/1K Pot = 44.6/8.7/6.9 K, IVC = 10 μbar, G1(fridge) = 500 mbar. G3(MB) = 332 mbar+1atm |
| 1230 | MC(Cernox)/Sorb/1K Pot = 34.9/7.5/6.0 K, IVC = 8.6 μbar, G1(fridge) = 484 mbar. G3(MB) = 334 mbar+1atm |
| 1239 | MC(Cernox)/Sorb/1K Pot = 26.8/6.7/5.38 K, IVC = 7.4 μbar, G1(fridge) = 473 mbar. MB = 2.8% / 338 mbar+1atm |
| 1246 | MC(Cernox)/Sorb/1K Pot = 20.3/5.9/4.7 K, IVC = 7.4 μbar, G1(fridge) = 465 mbar. MB = 12.6% / 343 mbar+1atm |
| 1252 | MC temp hit 10 K, open turbo to IVC. IVC pressure hit 5.4e-5 mbar after about a minute. |
| 1255 | MC(Cernox)/Sorb/1K Pot = 5.9/5.2/4.2 K, IVC = 10 nbar, G1(fridge) = 451 mbar. MB = 23.0% / 340 mbar+1atm |
| 1310 | MC(Cernox)/Sorb/1K Pot = 4.4/5.3/4.3 K, IVC = 1.9 nbar, G1(fridge) = 446 mbar. MB = 49.0% / 344 mbar+1atm |
| 1321 | MC(Cernox)/Sorb/1K Pot = 4.43/5.7/4.6 K, IVC = 1.6 nbar, G1(fridge) = 443 mbar. MB = 61.2% / 380 mbar+1atm |
| 1330 | MB level was going down a little, G3 has had some jumps up. End LHe transfer @ 54.1 % |
| 1345 | MC(Cernox)/Sorb/1K Pot = 4.45/5.9/4.7 K, IVC = 2.2 nbar, G1(fridge) = 516 mbar. MB = 54.3% / 158 mbar+1atm |