2015/06/23 (Tuesday)
| 0758 | Fill LN cold trap Dewar |
|---|---|
| 0800 | Checked phonon channels with DetectorReadout: all currently at correct baseline, ~ -0.8 V. |
| 0801 | Tower = 31.5 mK, Still = 2 mW / 0.11 mbar, G1/G2 = 210/190 mbar, 1K Pot = 1.69 K / 15 mbar |
| 0810 | Remove Cf source. Cf source had been inside shield at detector level overnight. |
| 0815 | Tried to check rate with Ba source, looking at MultiDAQ event rate. First raised all phonon thresholds from 25 to 100. Background: 10 Hz. With Ba at top of shield: 10 Hz. with Ba lowered down about 1 foot: 17 Hz. |
| 0820 | Placed Ba source inside mu-metal shield at approximate detector level. Restored phonon thresholds to 25. |
| 0830 | Flash DIB2&3 LEDs for 5 seconds |
| 0845 | Begin Ba run. |
| 0857 | Notice event rate quite low, 0.5 Hz. Less than 900 events recorded after randoms. Why so slow? CPU usage is very high, near 100%. |
| 0900 | Stop run. CPU usage drops to 15%. |
| 0905 | Moved Ba source to near top of mu-metal shield, about 60 cm above detector level. This seems to reduce CPU usage and improve event rate. |
| 0925 | Begin Ba run. |
| 0927 | After randoms, rate on EventBuilder drops from 10 Hz to 1 Hz and CPU usage rises from 80% to 98%… |
| 0930 | Firefox seems to be using a good chunk of processor. Stop Firefox. CPU usage drops to around 90%. Event rate increases to 5-10 Hz. |
| 0939 | Started an rsync job and noticed this also was a drain on the CPU. |
| 0940 | Stop run. |
| 1005 | Begin Ba run. |
| 1010 | CPU usage is high, near 100%, and event rate low, around 1 Hz, even though nonessential processes stopped. Perhaps should completely reboot computer and use only bare bones processes. |
| 1031 | Remove Ba source. |
| 1045 | Testing event rate & CPU usage. No source: 18 Hz, 70%; Ba at top of shield: 14 Hz, 80%. Ba down 1 ft: 1 Hz, 98%. |
| 1050 | Try some voodoo: in the past they saw low event rates when DCRC50 was used on DIB3 - apparent fix was to include DIB3 charge channels in the 'or' trigger. Tried this with no improvement. |
| 1055 | Try “quit” on MultiDAQ to free up some memory (previously we were just hitting “stop” to end runs). Then try taking data again. Had to load up old configuration to do this, then modify to more recent driver offsets… at some point during this the DCRCs went into a Bad State, tower temperature rose to 2.8K (yikes - could see rise in still pressure too). Powercycled DIB1/DCRC31 FETs. Fridge began cooling (not sure if power cycling FETs helped or not). Phonons generally railed - most could be restored to non-railed baselines with relock. High frequency noise in DIB1pA, could be removed by reducing front-end gain from 7 to 6. This actually went away after we had cooled to base, could again set gain back to 7. |
| Current driver offsets | ||||
|---|---|---|---|---|
| DIB | A | B | C | D |
| 1 | 0.036 | 0.024 | 0.028 | -0.012 |
| 2 | 0.092 | -0.004 | -0.014 | -0.020 |
| 3 | -0.086 | -0.022 | -0.108 | -0.086 |
| 1205 | Closed all programs and rebooted Vuk-01 |
|---|---|
| 1225 | Flashed, then tried test run. Not much improvement on event rates/CPU usage. No source: 14 Hz / 60%; Ba source at top of shield: 12 Hz / 70%; Ba source 1 ft down from top: 3 Hz / 98%. |
| 1234 | Begin background run. Rate ~10Hz during randoms, ~13Hz during triggers. |
| 1307 | Start data run. |
| 1323 | Stop data run, zero Q bias, flash. |
| 1349 | Start data run. |
| Updated driver offsets | ||||
|---|---|---|---|---|
| DIB | A | B | C | D |
| 2 | same | same | 0.034 | 0.026 |
| 1353 | Restart data run with new DO values above. |
|---|---|
| 1409 | Stop data run, zero Q bias, flash. |
| 1420 | Start data run. |
| 1436 | Stop data run, zero Q bias, flash. |
| 1450 | Start data run. |
| 1509 | Stop data run, zero Q bias, flash. |
| 1522 | Start data run. |
| 1537 | Stop data run, zero Q bias, flash. |
| 1550 | Start data run. |
| 1551 | New DO values: DIB 2 pC: -0.012; pD: -0.018. |
| 1556 | Restart data run with new DO values. |
| 1611 | Stop data run, zero Q bias, flash. |
| 1626 | Start data run. |
| 1641 | Stop data run, zero Q bias, flash. |
| 1653 | Start data run. |
| 1710 | Stop data run, zero Q bias, flash. |
| 1720 | Start data run. |
| 1735 | Stop data run, zero Q bias, flash. |
| 1745 | Start data run. |
| 1800 | Stop data run, zero Q bias, flash. |
| 1810 | Start data run. |
| 1825 | Stop data run, zero Q bias, flash. |
| 1841 | Start data run. |
| 1856 | Stop data run, zero Q bias, flash. |
| 1902 | Start data run. |
| 1920 | Stop data run, zero Q bias, flash. |
| 1930 | Start data run. |
| 1945 | Stop data run, zero Q bias, flash. |
| 1958 | Start data run. |
| 2013 | Stop data run, zero Q bias, flash. |
| 2022 | Start data run. |
| 2037 | Stop data run, zero Q bias. |
| 2044 | Restored 252 Cf source for overnight activation. |