2017/06/15 (Thursday)
| Status | Fridge warming up. LN2 traps are clean, ready to start cleaning mixture. Fridge is evacuated. 1K Pot needle valve is open. He and N2 gas are in the cryostat vacuum jacket. |
|---|---|
| 0910 | MC(Cernox) = 274.3 K. IVC = 1 bar (Pfeiffer), 770 mbar on mechanical gauge. |
| unfortunately 274 K is still a rather frosty temperature, a little above freezing. | |
| 0915 | Lab = 23.5 C, 40% humidity. Dew point around 281 K. MC is warming at 1.6 K/hour so another 4 hours until fridge is above dew point. |
| 0925 | Fill IVC to very close to 1 atm on mechanical gauge. Open valve to the IVC overpressure relief. |
| 0940 | Begin cryocleaning mixture through Trap 2. Open V6 to 12.9%. |
| 1000 | Flow stopped, increase V6 to 13.2% |
| 1115 | Flow stopped, increase V6 to 13.4% |
| 1120 | MC(Cernox) = 277.3 K |
| 1145 | Stop cryocleaning mixture after 125 minutes (although there may not have been flow for a lot of this time). Pump mix out of Trap 2 to dump. |
| 1205 | Remove Trap 2 from LN2 bath to let it warm up |
| 1215 | Begin cryocleaning mixture through Trap 1. Open V6 to 13.5%. |
| 1220 | Measure pressure in cryostat vacuum jacket: 10 mbar on Pfeiffer, <5 mbar on mechanical gauge |
| 1310 | MC(Cernox) = 279.7 K, according to LakeShore readout; on the LabView vi it's closer to 281 K, so the calibrations aren't quite the same. |
| 1310 | Begin pumping out cryostat vacuum jacket with scroll pump. After 15 minutes begin pumping with turbo pump. |
| 1325 | Stop cryocleaning mixture after 70 minutes. Pump mixture out of Trap 1 to dump. |
| 1330 | Turn off MC heater |
| 1335 | Turbo pressure = 6 ubar while pumping on cryostat vacuum jacket; valve out pump, cryostat vacuum jacket = 190 ubar. We'll disconnect the pumping line to lower the cryostat, but we may want to pump this out further before cooling again. |
| 1345 | MC(Cernox) = 280.3/281.7 K on LakeShore/LabVIEW. Begin lowering cryostat. |
| 1350 | Open (warm) Trap 2 to G1. Reads 54 mbar of contaminants after cleaning#1 (125 minutes). Trap seems close to room temperature, maybe a little cool to the touch; pressure seems flat over a few minutes. This is probably pretty close. Pump out Trap 2. Then put it in the LN2 bath. |
| 1400 | IVC is pretty cool to the touch, almost cold enough for water to condense on it, but not much. MC(Cernox) = 280.4/281.9 K. MC warming more quickly now. |
| 1425 | Begin cryocleaning mixture through Trap 2. Open V6 to 13.0%. |
| 1430 | Flow stopped, increase V6 to 13.3% |
| 1515 | IVC is now open. |
| 1520 | MC(Cernox) = 285.3/286.8 K. It's still warming to RT |
| 1540 | Stop cryocleaning mixture after 75 minutes. Pump mixture out of Trap 2 to dump. Turn off 3He pump. |
| 1620 | G2 (Dump) = 790.7 mbar, Pbarometric = 29.76 inHg, Dump pressure (adjusted) = 785.3 mbar |
| 1630 | Open (warm) Trap 1 to G1. Reads 45.3 mbar of contaminants after cleaning#2 (70 minutes). Trap seems to be at room temperature. Pump out Trap 1. Then put it in the LN2 bath. |
| 1640 | MC(Cernox) = 290.5/292.1 K. It's still warming to RT as Nick and Derek work on disassembly in clean tent. |
| 1715 | MC(Cernox) = 292.3/294.0 K. It's still warming to RT. Lab = 24.2 C, 35% humidity |
| 1717 | Complete de-install up to 100mK shields. |