| Status | Run 75 finished. Began warmup yesterday. 1K Pot pumped dry and isolated. All mixture in dump, fridge isolated. LHe Trap and LN2 Trap 1 still have contaminants. Some He gas in IVC and in Cryostat Vacuum Jacket. |
| 0000 | Recovery = 0.7 cuft/hr |
| 0300 | Recovery = 0.41 cuft/hr |
| 0600 | Recovery = 0.26 cuft/hr |
| 0855 | Recovery = 540267.0 cuft |
| 0900 | Recovery = 0.20 cuft/hr |
| 0945 | Begin disassembling lead/poly shield |
| 1215 | Finish removing lead/poly shield. |
| 1215 | MC(Cernox)/Sorb = 118.7/246.5 K |
| 1235 | MC(Cernox)/Sorb = 120.5/249.9 K, max scale for Sorb |
| 1600 | MC(Cernox) = 135.3 K, warming at 4.2 K/hr. Taking T_room to be 295.3 K this implies warming tau of 38.1 hours. Taking dew point to be 273 K this implies we'll reach dew point in 75.1 hours, which is 20 Feb (Sunday) at 7:04 pm. |
| | note: lab thermometer reads 22.2 C, 21% humidity. This implies dew point less than 0 C. So I'm conservatively upping it to about 0 C. |
| 1635 | Let about 100 mbar N2 gas into vacuum manifold. Then open cryostat vacuum jacket valve to let this into the vacuum jacket. Vacuum jacket → 4.0 mbar |
| 1635 | Recovery = 540267.9 cuft |
| 1650 | Close MB recovery valve. Open V1a to monitor MB pressure on G3. This will build up as the fridge warms - we should release the pressure occasionally. |
| 1650 | MB(G3) = 137 mbar+1atm |