2015/07/15 (Wednesday)
| Current configuration: DIB1/2/3 → 100MHz filter/none/none → DCRC55/33/50. Baking overnight, no source. | |
| 0853 | MC/Tower/Coldplate = 123/323/178 mK, Still = 0 mW / 0.15 mbar / 1.11 K, G1/G2 = 250/235 mbar, 1K Pot = 1.70 K / 13 mbar, Main bath = 61.0% |
| 0848 | Stop flashing detector. |
| 0856 | Fill LN2 cold trap Dewar. |
| 0927 | Tower falls to 32 mK |
| 0930 | MC/Tower/Coldplate = 26.4/31.7/145 mK, Still = 0 mW / 0.10 mbar / 1.11 K, G1/G2 = 215/200 mbar, 1K Pot = 1.69 K / 13 mbar, Main bath = 59.5% |
| pulse quality | low frequency noise | |
|---|---|---|
| DIB1 | M/D/P/P | 1-2 kHz @ 5/3/5/9 mVpp |
| DIB2 | P/P/M/D | ~1 kHz @ 6/4/5/3 mVpp |
| DIB3 | P/D/P/P | ~1 kHz @ 3/4/6/10 mVpp |
| 1020 | Estimated true event rate by looking for pulses in random 60 ms traces. Counted 45 events in 19 traces (1.14 seconds) yields event rate of 39 Hz. Note that this implies that about 16% of events will have pileup. |
|---|
| Current thresholds | ||||
|---|---|---|---|---|
| pA | pB | pC | pD | |
| DIB1 | 25 | 25 | 20 | 30 |
| DIB2 | 25 | 25 | 20 | 20 |
| DIB3 | 20 | 20 | 15 | 25 |
| 1030 | Start a data run but forgot to set voltage bias. Stop run. |
|---|---|
| 1033 | Set -4/+4 V. Start bkg data run. |
| 1053 | Stop data. Set 0/0 V. Flash 30 seconds. |
| 1145 | Less noise now: |
| pulse quality | low frequency noise | |
|---|---|---|
| DIB1 | M/D/P/P | none seen |
| DIB2 | P/P/P/D | ~1 kHz @ 4/0/3/0 mVpp |
| DIB3 | P/D/P/P | ~2 kHz @ 0/2/0/5 mVpp |
| 1148 | Set -4/+4 V. Start bkg data but data rate bogs down during randoms. Stop run. |
|---|---|
| 1152 | Try taking data again but bogs down again. Both times at about 800 randoms. |
| 1203 | Set to 0/0 V, experiment with taking data… Looking at the Readout vi, I noticed I had left the Qo trigger on with very low threshold to look at random noise. Reset the triggering to only the four phonons on every board using the Readout vi. This fixed the data rate problem. Apparently the Qo trigger was set on the DCRCs, and apparently this affects the data rate even during the randoms. |
| 1207 | Flash 30 seconds |
| Current thresholds | ||||
|---|---|---|---|---|
| pA | pB | pC | pD | |
| DIB1 | 25 | 25 | 20 | 30 |
| DIB2 | 25 | 25 | 20 | 20 |
| DIB3 | 20 | 20 | 20 | 25 |
| 1243 | 200 Hz noise on DIB3 pD, 4 mVpp and DIB2pB, 4 mVpp. |
|---|---|
| 1307 | Stop data. Set 0/0 V. Flash 30 seconds. |
| 1345 | Background rate is about 20 events / 0.6 s = 33 Hz. |
| 1350 | Put Cf source near top of shield. Rate increases to about 24 events / 0.3 s = 80 Hz. |
| 1355 | Ensure trace length and triggers are set properly in Readout vi. |
| 1356 | Set -4/+4 V. Start Cf data run. |
| 1414 | Stop data. Set 0/0 V. Flash 30 seconds. |
| 1504 | Set -4/+4 V. Start Cf data run. |
| 1524 | Stop data. Set 0/0 V. Flash 30 seconds. |
| 1548 | Set -4/+4 V. Attempt run but LabVIEW error occurred involving enqueing a trigger… stop data. |
| 1558 | Start Cf data run. No errors. |
| 1617 | Stop data. Set 0/0 V. Flash 30 seconds. |
| 1638 | Set -4/+4 V. Attempt run but data rate bogs down after randoms. Stop data. Close Firefox and increase DIB3pC threshold to 20. |
| 1644 | Start Cf data run. Rate fine. |
| 1702 | Stop data. Set 0/0 V. Flash 30 seconds. |
| 1703 | Remove Cf source from fridge. |
| 1725 | Fill LN2 cold trap Dewar. |
| 1730 | Start baking detector. |