2021/04/18 (Sunday)
- Lab in-person: Matt
- Virtual partner: Derek
| Status | Run 74 in progress. Cooling down after fixing DIB2qI short which had reappeared at around 130 K. Initial LHe transfer 2 days ago, as we approached 4K we seem to spring a leak in the IVC. (First evidence around 40 K). Can't seem to pump it out. |
|---|---|
| 1115 | Matt enters lab |
| 1115 | MB = 13.2% |
| 1115 | IVC = 0.4 mbar. We are not pumping on it, just monitoring it. |
| 1115 | Isolate IVC then pump out manifold with Scroll then Turbo. It pumps out just fine, falls to 10 nbar in a couple minutes. Nothing wrong with the pumps and probably the gauge is OK too. |
| 1120 | Fill LN2 cold trap bath |
| 1120 | Turn off 3He pump. Mixture still open to dump, trap1, fridge. |
| 1120 | Start pumping IVC with scroll. After 15 minutes Scroll pressure still at 0.16 mbar, not good. |
| 1135 | Valve out Scroll. After a minute IVC = 0.25 mbar. |
| 1135 | Set up fridge computer camera taped to lamp to monitor IVC pressure remotely. |
| 1140 | IVC = 0.4 mbar. |
| 1140 | Matt exits lab. |
| 2030 | Fridge temperatures are beginning to rise slightly as MB boils away MC(Cernox)/Sorb/1K Pot = 4.30/6.2/4.94 K |
| 2030 | IVC = 0.4 mbar |