2018/02/28 (Wednesday)
| Cryo | |
|---|---|
| 0830 | G1 had crept up to 26.8 mbar, pump this out with scroll pump. |
| 0835 | Check warm trap contents after yesterday's cleanings: Trap 2 = 14.3 mbar. (up from min of about 0.5 mbar.) Open Trap 1 to G1 at the same time: only goes up another 0.2 mbar, that's surprisingly low. Pump out traps. |
| 0850 | Return evacuated cold traps to LN2 bath |
| 0910 | Start cryocleaning mixture through Trap 2, V6 = 12.6% |
| 0955 | Increase V6→13.0% to reestablish flow |
| 1110 | Increase V6→13.1% to reestablish flow |
| 1130 | Stop cryocleaning, pump mix back to dump |
| 1320 | Remove Trap 2 from bath to let warm up. |
| 1615 | Check warm Trap 2: 4.5 mbar. Pump out with scroll pump. |
| 1635 | Put Trap 2 back in LN2 bath |
| Cryocleaning log | ||
|---|---|---|
| date | duration (minutes) | contaminants removed (mbar) |
| Feb 27 | 55 | 13.5 |
| Feb 27 | 55 | 0.2 |
| Feb 28 | 140 | 4.5 |
| Install | |
|---|---|
| 0916 | Beginning tower install. Orient with DIB1 facing West and DIB2 facing east. |
| 0945 | Tower attached to 30mK can. |
| 1110 | 100mK stage and 600mK stage installed |
| 1154 | 4K stage installed. Install SQUET ZC-26 on DIB2. Begin electrical check. |
| 1205 | Electrical check looks good for all the charge-related stuff. A few problems we should check later… |
| 1210 | Install SQUET ZC-39 on DIB1. Begin electrical check |
| 1215 | Electrical check looks good. We measured qI-qO continuity on both DIBs, and qI/qO-detector ground on DIB1, all look good, so this is enough to show all electrodes are connected. |
| 1430 | Installation finished, finishing sealing IVC. |
Electrical problems that won't affect this run but should be investigated later:
- DIB1 Feedback Coil-to-Return reads open
- DIB1 QETB Bias-to-Return reads open (all 4)
are these in the SQUET or in the stripline??
| 1430 | Begin pumping IVC with scroll pump, starting gently, gradually opening the valve further and further |
|---|---|
| 1515 | Pumping pressure on IVC = 7.4e-2 mbar = 74 μbar, switch to pumping with turbo pump |
| 1520 | Connect Leak Detector to IVC and valve out turbo pump. Leak signal → 18 pbarL/s. |
| 1535 | Squirt-check all IVC connections. No increase in leak detector signal, looks good. |
| 1540 | Switch back to pumping IVC with turbo pump |
| 1545 | IVC pumping pressure = 0.86 μbar, IVC = 190 μbar with pump valved out |
| 1610 | Raised main bath. Put the small screws in first. It was much easier than usual to get the screws in this time. |
| 1615 | IVC pumping pressure = 0.25 μbar, IVC = 220 μbar with pump valved out (got distracted and left it valved out for ~30 minutes) |
| 1640 | Check pressure in 1K Pot: 24 mbar on P2. Pump out with scroll pump. |
| 1645 | Check fridge pressure: Still side = 0.20 mbar at P1. LHe trap: 3.3 mbar at G1. Condenser side = 0.6 mbar at G1. Pump all this out with scroll pump. |
| 1705 | Open fridge lines up to (cold) Trap 1 to cryopump out any remaining contaminant gas |
| 1705 | Fill LN2 cold trap bath |