| 0945 | Attached LB's pressure gauge to pumping manifold. Evacuated only the lines leading up to turbo pump. Haven't checked any pressures yet. |
| 1000 | Filled LN2 cold trap. |
| 1143 | Pressure in IVC ~ 5E-5 mbar. |
| 1300 | Helium background rate 5.4E-9 mbar l/s when helium leak checker isolated. Helium leak rate is too high. Start regeneration cycle. |
| | Helium transfer stick no longer lowers comfortably into cone. Attempts to straighten it were reasonably successful: it's good enough. Stick marked as a precaution to prevent operator from lowering it past cone. |
| 2000 | Regeneration didn't seem to have too much effect. Switched to departmental leak checker. Similar behaviour witnessed, implying that background leak rate in laboratory is high. Unsure of reasons why, but decide to use less conservative figure of 1E-6 mbar l/s for definition of gross leak. As run time is expected to be relatively short, we can live with this rate. |
| | Background leak rate during spray test: 2.2E-7 mbar l/s. No change witnessed. Raise dewar. |
| | Pump mixture into dump. Extract helium and nitrogen cold traps for cleaning. Clean cold traps and replace. Fill N2 cold trap full and resume cryocleaning. |
| | Insert nitrogen transfer stick. Pump main bath and overpressurise it with helium. Background leak rate 1.7E-7 mbar l/s; no change witnessed. Fill IVC with 4.6 mbar nitrogen exchange gas. Start nitrogen transfer. |
| 2255 | Nitrogen level meter resistance 1.33 kΩ. Nitrogen transfer completed. Attach ping-pong ball. |