| | Current setup: iZIP mode, DIB1/2/3 → cables → 3.2 MHz filters → DCRC55/33/50. |
| | Overnight: Taking Cf data. Last flash at 7:21 am. |
| 0920 | Fill LN2 cold trap Dewar, maybe not full - storage Dewar ran out. G1/G2 dropped during LN2 fill as usual. |
| 0925 | Remove Cf source from fridge. |
| | A few excursions in Tower temperature since ~9:30, rose around 1 mK and fell. Related to low bath level?? |
| 1045 | Tower/MC(H35)/MC sensor/Cold Plate = 31.2/25.5/42.1/159 mK, Still = 1.38 K / 0.11 mbar, G1/G2 = 185/165 mbar, 1K Pot = 1.72 K / 20 mbar, Main bath = 15.4% |
| 1105 | Start LHe transfer at 14.5% |
| 1200 | Finish LHe transfer at 68.7% |
| 1320 | Place Ba source inside top most part of the back shield for 15 minute Ba runs. |
| 1330 | Take Ba data, two 15min series: first at -/+4V then -/+2V. 1000 initial randoms, 2000 events/file, 30s flash & 30min cooldown in between series. Friday's phonon thresholds used. |
| | Random event rate: ~10Hz. Triggered event rate: ~15Hz. |
| 1445 | Remove Ba source and place back in safe. |
| 1527 | Start background data, but stop immediately because DIB1 pB is shifted and not showing pulses. Looks unlocked. Investigate using Detector Readout VI. |
| | DIB1 pB would only show ~150Hz ~10mVpp irregular noise. Changing QET bias didn't show pulses until after cranking it up past 400uA and lowering it until ~250uA when pulses began to appear again. Now pulses show up at the previously used QET bias of 127uA, though the triggering threshold needed to properly trigger is now ~2x what it was (100 instead of 50ADC bins). Not sure why. |
| 1545 | DIB1 pB required a change of Driver Offset to unrail the channel after it's “QET reset” (or “reQET”, if you will). Changed from 0.024V to 0.042V. As noted earlier, the “QET reset” also caused a dramatic increase in the necessary phonon trigger threshold for DIB1 pB. The new threshold is 80 ADC bins. The updated phonon threshold values are below: |