2019/05/30 (Thursday)
| 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 → DCRCX(4)/DCRC50(3) DCRC33(2) → 1kV power supply → HV input |
|---|---|
| 0000 | Tower = 58.0 mK |
| 0850 | Tower/MC/Coldplate = 56.9/31.6/200 mK, Still = 1.29 K / 0.095 mbar, G1/G2 = 186/181 mbar, 1K Pot = 1.63 K / 22 mbar. MB = 71.3% |
| Tower temperature continues to fall linearly, slowly | |
| 0900 | Fill LN2 cold trap bath |
| 0910 | Flash the LEDs on DCRC3/4 for 30 seconds. Tower temperature spikes to 58.7 mK then falls. Not a very big spike - but we should consider that the tower temperature is elevated by the slow cooling of the electrode, so maybe that makes the increase less noticeable. Also, the LEDs are pointed at the bottom of the detector, so they don't hit the thermometer directly. |
| Looked at yesterday's 3 hours of data, after processing with last run's configuration. Saw the 60 keV peak and did a simple calibration in PTOF (no attempt to balance channels). Noise width was around 710 eV. Better than last run (1500-2000 eV) but worse than Run 66 (around 250 eV). | |
| 1500 | Adjust QET biases, this time set most/all of them lower. Now a lot of them are below an oscillatory part of the transition. But this might give stronger pulses, maybe better signal-to-noise. |
| 1531 | Start a sequence of 9 20-minute background series at HV = 0V CDMS detector: Driver Gains = 1x, DCRC4/3 QET biases = (420/360/430)/(420/400/450) uA, Front-End Gains = (2/2/3)/(5/5/5) 1000 BOR randoms, trigger on DCRC4pA/B/C threshold = 4/4/4 use SimpleDataLoopNoFlash.msl |
| 1535 | Abort run because DCRC4 B&C railed. Increase their QET biases a bit and try again. |
| 1544 | Start a sequence of 9 20-minute background series at HV = 0V CDMS detector: Driver Gains = 1x, DCRC4/3 QET biases = (420/370/440)/(420/400/450) uA, Front-End Gains = (2/2/3)/(5/5/5) 1000 BOR randoms, trigger on DCRC4pA/B/C threshold = 4/4/4 use SimpleDataLoopNoFlash.msl |
| 1545 | Tower = 56.1 mK |
| 1550 | Looking with BatViewer the trigger rate seems to high. Adjust DCRC4pB trigger threshold 4→5 |
| 1554 | Better but maybe still triggering a little too much. Adjust DCRC4pC trigger threshold 4→5 |
| 1623 | Fill LN2 cold trap bath |
| 1628 | MB = 60.3% |