2015/07/08 (Wednesday)
| overnight status: baking detector, Cf source on fridge, DIB1/2/3 → no filter/100 MHz C filter/3.2 MHz pi filter → DCRC55/33/50 | |
| 0900 | Tower = 300 mK, Still = 0 mW / 0.14 mbar, G1/G2 = 230/210 mbar, 1K Pot = 1.67 K / 11 mbar (a bit low), Main bath = 52.5% |
| 0901 | Turn off flashing. Takes about 30 minutes to cool to 32 mK. |
| 0905 | Fill LN2 cold trap Dewar |
| 0942 | Tower = 31.5 +/- 0.2 mK, still = 0 mW/0.11 mbar, G1/G2 = 205/190 mbar. 1K Pot = 1.67 K/11 mbar. |
| 0950 | Remove Cf source. |
| 1050 | Power down DCRC55 and 50. Move 3.2 MHz filter from DIB3 to DIB1. |
| 1058 | Zap SQUIDS. |
| 1124 | On DIB1, have to adjust QET biases to get A1, C1 to show up. DIB3 biases set to previous no-filter values: |
| Current QET biases with DIB1/2/3 → 3.2MHz/100MHz/no filter → DCRC55/33/50 | ||||
|---|---|---|---|---|
| pA | pB | pC | pD | |
| DIB1 | 102.5 | 101.1 | 109.1 | 73.7 |
| DIB2 | -88.1 | -90.7 | -107.9 | -81.9 |
| DIB3 | 72.4 | 85.1 | 55.3 | 89.0 |
| Visual assessment of phonon quality before/after filter swap | |||||
|---|---|---|---|---|---|
| pA | pB | pC | pD | baseline noise | |
| DIB1 → no filter → DCRC55 | mediocre | decent | poor | decent | 1KHz 10mVpp in C |
| DIB1 → 3.2MHz → DCRC55 | poor | good | poor | mediocre | 1KHz at 3/0/2/6 mVpp |
| DIB2 → 100MHz → DCRC33 | mediocre | mediocre | poor | mediocre | 100Hz 10mVpp in D |
| DIB2 → 100MHz → DCRC33 | poor | mediocre | poor | good | 200Hz 4mVpp in B,D, 1KHz 4mVpp in B |
| DIB3 → 3.2MHz → DCRC50 | mediocre | good | poor | poor | 200Hz 10 mVpp in D |
| DIB3 → no filter → DCRC50 | mediocre | good | poor | poor | not much |
note: presence of baseline noise correlates with poor pulse shape, even though pulse shapes don't quite look like noise superimposed on a good pulse.
| Visual assessment of phonon quality before/after filter swap | ||||||
|---|---|---|---|---|---|---|
| outer | central ring | inner | ||||
| pA | pB | pC | pD | pE | pF | |
| Side 1 | mediocre/good | mediocre/poor | poor/poor | poor/poor | poor/poor | decent/good |
| Side 2 | mediocre/mediocre | mediocre/mediocre | mediocre/poor | decent/mediocre | poor/poor | good/good |
note: poor shapes seem to be concentrated in “central ring” channels
| 1154 | Set QET biases to 0 for superconducting run. Apply -4/+4 V to Q biases. Take 1000 randoms. Many channels (A1, A2, B2, C2, D2, and several DIB3 channels) all railed. Relocking only helped a few, so driver offset needed to be adjusted. |
|---|---|
| 1204 | Stop after 1000 randoms. Zero Q bias, flash 30s. |
| 1230 | Set QET biases to transition values, listed above. Apply Q bias of -4/+4 V. B1 rails. Relock. |
| 1240 | Take 1000 randoms. When randoms stopped and triggers began, rate got bogged down. Could be due to mis-set triggers and we don't really care at this point so… Zero Q bias, flash 30s. FETs on DIB2 froze out somehow causing base temperature to be at ~37 mK. |
| 1328 | Use FET heater. Base temperature back at 31 mK. Set QET biases to +/- 250 uA to drive sensors normal. On DIB2, set all QET biases to -300 uA because at -250 uA, pulses were still being frequently seen. |
| 1333 | Set -4/+4 V. Take 1000 randoms. Take 1000 randoms. At ~800 randoms, rate bogged down. Finish taking randoms at ~2 Hz. |
| 1338 | Stop, 0 Q bias, flash 30s. |
| 1357 | Reapply QET biases. |
| 1503 | Flash 30s. |
| 1518 | Set all phonon thresholds to 30 ADC bins. Set -4/+4 V Q bias. Start data run. |
| 1539 | Stop data, zero Q, flash 30s. |
| 1558 | Start data (-4/+4). |
| 1615 | Stop data, 0 Q, flash 30. |