2018/07/17 (Tuesday)
| Setup: DIB1/3/4 → 3.2 MHz filters 2/3/1 → cable 3/1/2 → gender changer 3/?/2 → HVConn 1/3/2 → HV 1/2 → DCRC55(1)/DCRC50(3) | |
| 0943 | Tower/MC/Coldplate = 31.3/29.1/184 mK, Still = 1.4 K / 0.150 mbar / 6 mW, G1/G2 = 140/131 mbar, 1K Pot = 1.54 K / 8.5 mbar. MB = 35.0% |
| 0948 | Fill LN2 cold trap full. |
| 1000 | DCRCs are behaving again (no stuck output) but noise/low energy events observed yesterday are still present. |
| 1007 | Turning off the room lights and clean room filters doesn't help. |
| 1010 | 1K pot has been drifting down over the last several days. Open 1K Pot needle valve 75° → 80°. 1K Pot → 1.6 K / 32 mbar |
| 1115 | Tower = 32.8 mK |
| 1131 | Start 30-minute 0 V background data series, Driver Gains = 2x, QET biases = (280/260/305)/(140/295/300) uA, Front-End Gains = 10, 1000 initial randoms, trigger on DCRC3pB/C/D threshold = 8/16/16. To be compared to bias scan data from 2018/07/01, but shifted some DCRC3 QET biases slightly to avoid oscillations. |
| 1220 | Tower temp wandered up to 34.5 mK and back down to 32.7 mK during that series. |
| 1223 | Set HV=40V with 15% prebis for 5 min. |
| 1234 | Start 30-minute 40 V background data series, Driver Gains = 2x, QET biases = (280/260/305)/(140/295/300) uA, Front-End Gains = 10, 1000 initial randoms, trigger on DCRC3pB/C/D threshold = 8/16/16. To be compared to bias scan data from 2018/07/01 |
| 1236 | Tower = 32.6 mK |
| 1318 | Tower = 31.0 mK |
| 1453 | Start LHe transfer @ MB = 27.1% |
| 1542 | End LHe transfer @ MB = 77.1% |
| 1615 | Set HV=0V |
| 1625 | 1K pot has been falling, now 1.55 K / 12 mbar Open 1K Pot needle valve 80° → 90°. Pot → 1.66 K / 45 mbar. Watched traces, didn't see any obvious change. |
| 1640 | Fill LN2 cold trap bath |
| 1129 | 1K pot failed. G1/G2 = 860/790 mbar, 1K Pot = 4.5 K / 1.3 mbar. Close V6 and open V14 to stop circulation and relieve pressure. G1/G2 begin to fall. |