2019/04/25 (Thursday)
| Status | IVC passed leak check, pumped out. Main bath raised. 1K Pot needle valve closed. Mixture has been cleaned twice. Recovery system leak check performed overnight - MB + reco lines up to just before the meter were pressurized with helium, watching the pressure go down. |
|---|---|
| 0840 | Turbo on IVC = 25 nbar. |
| 0840 | Main bath (G3) = 115 mbar + 1atm. |
| 0845 | LN2 Trap 2 is warm. Check contents: 9.2-1.7 = 7.5 mbar on G1. Pump out with scroll pump. |
| 0915 | Start cryocleaning mixture through LN2 Cold Trap 1, V6 = 12.7% |
| 0920 | Increase V6 → 13.0% to restart flow |
| 0940 | Increase V6 → 13.1% to restart flow |
| 1100 | Stop cleaning through Trap 1 after 105 min. G2 flow pressure was 575-630 mbar. Pump mixture to dump. Removed 4.7 mbar |
| 1130 | Start cryocleaning mixture through LN2 Cold Trap 2, V6 = 13.1% |
| 1145 | Increase V6 → 13.2% to restart flow |
| 1150 | Turbo on IVC = 22 nbar. With turbo valved out for a few minutes, IVC = 250 nbar. |
| 1215 | Increase V6 → 13.3% to speed up flow |
| 1230 | Stop cleaning through Trap 2 after 60 min. G2 flow pressure was 575-680 mbar. Pump mixture to dump. Removed 5.2 mbar |
| 1245 | LN2 Trap 1 is mostly warm. Check contents: 6.1-1.4 = 4.7 mbar on G1. Pump out with scroll pump. |
| if we're going to do LN2 today we should start now. Let's hope mixture is clean enough. | |
| 1300 | Check fridge pressures: LHe trap/Condenser/Still = 4.3/0.4/0.13 mbar. Pump out with scroll pump. |
| 1310 | Open dump to both sides of fridge lines via LN2 cold trap 1. |
| 1340 | With 1K Pot speedivalve and needle valve closed, pump on Main bath with scroll pump. Once P2 < 100 mbar, open 1K pot speedivalve and needle valve (5 turns) to pump out 1K pot volume to < 1 mbar on P2. |
| 1350 | Close off scroll pump, then pressurized bath and 1K Pot (both sides) to about 0.5 bar with helium. Then pump it out again with scroll pump to < 1 mbar. |
| 1355 | Pressurize main bath and 1K Pot (both sides) to 250 mbar +1atm on G3, then close 1K Pot speedivalve and needle valve. |
| 1405 | Turbo on IVC = 22 nbar. With turbo valved out for a few minutes, IVC = 250 nbar. |
| 1410 | Let 5.4 mbar He exchange gas into IVC |
| 1425 | MC(Cernox) = 298.9 K, Sorb = >249 K (max), IVC = 5.4 mbar, G1 (fridge) = 214 mbar, Level resistor = 0.987 kΩ |
| hmm, fridge pressure is surprisingly low. Oh - because I turned off the 3He pump. Usually we leave it on so that all mixture is pushed into the fridge. | |
| 1425 | Turn on 3He pump and open V9. |
| 1430 | MC(Cernox) = 298.9 K, Sorb = >249 K (max), IVC = 5.4 mbar, G1 (fridge) = 617.2 mbar, Level resistor = 0.987 kΩ |
| 1430 | Begin LN2 transfer |
| 1455 | MC(Cernox) = 292.7 K, Sorb = >249 K (max), IVC = 4.6 mbar, G1 (fridge) = 618.9 mbar, Level resistor = 0.996 kΩ |
| 1505 | MC(Cernox) = 280.5 K, Sorb = >249 K (max), IVC = 4.0 mbar, G1 (fridge) = 619.7 mbar, Level resistor = 1.006 kΩ |
| 1525 | MC(Cernox) = 257.5 K, Sorb = >249 K (max), IVC = 3.4 mbar, G1 (fridge) = 619.8 mbar, Level resistor = 1.014 kΩ |
| 1545 | MC(Cernox) = 229.7 K, Sorb = >249 K (max), IVC = 3.0 mbar, G1 (fridge) = 619.6 mbar, Level resistor = 1.038 kΩ |
| 1610 | MC(Cernox) = 188.8 K, Sorb = >249 K (max), IVC = 2.5 mbar, G1 (fridge) = 619.0 mbar, Level resistor = 1.093 kΩ |
| 1630 | MC(Cernox) = 159.3 K, Sorb = >249 K (max), IVC = 2.2 mbar, G1 (fridge) = 618.2 mbar, Level resistor = 1.154 kΩ |
| 1655 | MC(Cernox) = 134.2 K, Sorb = 217.6 K, IVC = 1.9 mbar, G1 (fridge) = 617.1 mbar, Level resistor = 1.247 kΩ |
| 1710 | MC(Cernox) = 121.4 K, Sorb = 177.7 K, IVC = 1.9 mbar, G1 (fridge) = 616.1 mbar, Level resistor = 1.280 kΩ |
| 1715 | Cease LN2 transfer and put ping pong ball on main bath port. |