| | 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) |
| | overnight: 100V sequence with flashing. Last flash at 01:45. Channels are all railed this morning. |
| 1010 | Tower/MC/Coldplate = 37.5/33.0/201 mK, Still = 1.43 K / 0.085 mbar, G1/G2 = 130/128 mbar, 1K Pot = 1.36 K / 1.6 mbar. MB = 67.9% |
| | 1K Pot very low, looks like it has run dry. Luckily this has not caused a fridge failure. Still and circulation pressures are also low, but base is elevated slightly. |
| 1015 | Open 1K Pot Needle Valve about 10 degrees further. 1K Pot → 1.46 K / 0.45 mbar. Still → 0.095. Tower rises 0.5 mK then starts falling. |
| | 20 minutes after tweaking the needle valve, the pot pressure&temperature went into oscillatory mode (this is the “good mode”, probably means the pot is drawing in LHe and maintaining a level). 1K Pot pressure/temperature are drifting downward however. |
| 1015 | Fill LN2 cold trap bath |
| 1130 | Tower = 36.8 mK, Still = 0.100 mbar, G1/G2 = 152/151 mbar, 1K Pot = 1.48±0.01 K / 5.0 mbar, drifting downward. |
| 1145 | Start sequence of 4 30-minute background data series at HV = 100V, with 1% prebias for 5 min (remote HV not calibrated above 100V), Driver Gains = 2x, QET biases = 290/270/315/140/315/310 uA, Front-End Gains = 10, 1000 initial randoms, trigger on DCRC3pB/C/D threshold = 10/20/20, 30s flash, 30min cooldown, using sequencer script DataLoop_100V-1_5PreBias-30Flash-30Wait-30minData.msl. Tower = 36.8 mK. |
| 1150 | Look at pulses during prebias time by disabling logger and starting a run manually. Adjust DCRC3 driver offset. Stop run and re-enable logger before sequence finished pre-bias phase. |
| 1240 | 1K Pot has fallen to 1.38 K / 2.0 mbar and is no longer oscillating. Open needle valve additional 10 degrees. Stronger effect, Pot peaks at 1.7K / 65 mbar, then settles… |
| 1305 | 1K Pot = 1.55 K / 9.0 mbar, oscillating. |
| 1405 | 1K Pot = 1.48 K / 5.0 mbar, oscillating. It keeps drifting downward. Not stable, unfortunately. |
| 1425 | 1K Pot = 1.43 K / 3.4 mbar, oscillating. Keeps falling. |
| 1440 | 1K Pot = 1.40 K / 2.4 mbar, not oscillating. Open needle valve another 10 degrees further. |
| 1445 | Check on data. All DCRC3 channels railed at the beginning of the second series (07180606_1306). Thereafter, the dumps are empty since we're triggering on DCRC3. We are in the third series now (07180606_1420). Use the DCRC control GUI to re-lock DCRC3 channels. Data starts triggering again. |
| 1536 | During prebias for final series, DCRC3 channels are railed again. Relock and adjust them using the SQUID tuning GUI before data starts. |
| 1555 | 1K Pot = 1.52 K / 6.5 mbar, oscillating. Falling, but maybe a little more slowly than earlier today. |
| 1710 | Fill LN2 cold trap bath |
| 1710 | 1K Pot = 1.49 K / 5.0 mbar, oscillating. Pretty low, worried that it won't last the night, so open needle valve additional 10 degrees. |