| 0230 | Tower installation procedure complete. Evacuate IVC. |
| 1845 | IVC pressure 1.4E-4 mbar: a bit high; maybe due to a leak or outgassing. Tighten screws holding bottom indium seal. |
| 1900 | Perform leak check spray test on all four indium seals and black & red pressure relief valve above IVC. Background helium leak rate 1.2E-8 mbar l/s. Helium leak rate rose to 2.2E-8 mbar l/s during spray test, before falling to 1.7E-8 mbar l/s. This appears to simply be due to the stabilisation of the leak check rate as no sharp spike was witnessed. No need to repeat measurement as final check will occur once dewar is raised: no gross leak detected. |
| | Pump out IVC with turbo pump and isolate leak checker. Raise dewar. |
| 2215 | Open line to leak checker and isolate turbo pump. Background helium leak rate 9E-9 mbar l/s. Evacuate main bath and overpressurise with He-4 gas. Helium leak rate increases tp 1.1E-8 mbar l/s. No spike, so no gross leak. However, there may be a smaller leak. With any luck, we won't see it at 77 K. |
| | Evacuate 1 K pot. |
| | Close gate valve and condenser line speedivalve to isolate fridge. Close valves V1 & V6 on IGH to isolate mixture pumping line and helium cold trap. |
| | Fill IVC with 4.6 mbar N2 exchange gas. Commence nitrogen transfer. |
| 2350 | Start cryocleaning mixture through nitrogen cold trap 2. |