| 0210 | IVC pressure 1.2E-3 mbar. Tighten screws on bottom indium seal. |
| | IVC pressure is a little high, but behaviour appears to be consistent with other runs. Due to the fault in the PKR 251 pressure sensor before the upgrade, it is difficult to determine whether the upgrade has had any effect on the evacuation rate. There are several items that have been introduced, such as the MIT-style stripline and stripline crossover PCBs, which may lead to outgassing. I do not believe the IVC pressure is sufficiently low enough to allow for a nitrogen transfer. However, in an effort to save time, the dewar should be raised. Worst comes to worst and a leak is detected in a few hours, the dewar can be lowered and its location can be investigated. If there is no leak, time would be saved. It would be nice to complete the first helium transfer before the planned power cut on Friday 16th August from 4 pm to 9 pm. |
| 0245 | Fill N2 cold trap full. Close gate valve and condenser line speedivalve to isolate fridge. Close all valves on IGH and nitrogen cold trap 1 speedivalve to stop recovering mixture. Pressure in G2 686 mbar. Start cryocleaning mixture through nitrogen cold trap 2 (valve V6 on IGH open to 14.1%). |
| 0500 | Raise dewar. |
| | Cryocleaning has stagnated. Open valve V6 on IGH to 14.3%. |
| 1245 | Filled LN2 cold trap. |
| 1400 | Ran another electrical check. No new problems found! |
| 1735 | IVC pressure 2.5E-4 mbar. It's a little high, but it would be prudent to conduct a leak check. Isolate turbo pump and open line to leak checker. Background helium leak rate 7.3E-9 mbar l/s. Spray test conducted on ebox flange resulted in a gradual increase in leak rate to 7.5E-9 mbar l/s: no gross leak. |
| 1745 | Evacuate main bath and 1 K pot. Background helium leak rate 6.4E-9 mbar l/s. Overpressurise main bath with He-4 gas. Leak rate drops to 6.3E-9 mbar l/s: no gross leak in IVC flanges within main bath at room temperature. |
| | Isolate leak checker and continue to evacuate IVC with turbo pump. |
| 2315 | IVC pressure 1.9E-4 mbar. It will have to do. Stop evacuation and fill IVC with 4.6 mbar of N2 exchange gas. Evacuate main bath and overpressurise with He-4 gas. Evacuate 1 K pot. Commence nitrogen transfer. |