2019/08/14 (Wednesday)
| 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)/DCRC55(1) DCRC33(2) → 1kV power supply → HV input NaI B → DCRC50(3) pB Lead/poly shield erected, south wall partial lead only (with NaI detectors). |
|---|---|
| PuBe source has been removed from lab. | |
| 1010 | Fill LN2 cold trap bath. |
| 1020 | Tower/MC/Coldplate = 39.0/30.3/201 mK, Still = 1.31 K/ 0.09 mbar / 0 mW, G1/G2= 107/102 mbar, 1K Pot = 1.636 K / 24 mbar. MB= 63.7% |
| Let's set up data with a source. | |
| 1100 | Check event rate. Count number of visible pulses in 50 traces, three trials: count 2, 2, 4 pulses. 16±6 Hz. (that's strangely low.) Using DCRC1pB. |
| 1105 | Check event rate. Count number of visible pulses in 50 traces, three trials: count 2, 7, 6 pulses. 31±8 Hz. Using DCRC1pD. |
| 1110 | Check event rate. Count number of visible pulses in 50 traces, three trials: count 4, 4, 7 pulses. 31±8 Hz. Using DCRC1pD. |
| 1125 | Build lead castle for Na-22 source, on stool south of the lead/poly fridge shield. It's pointing at the unshielded gap between the NaI detectors. |
| 1130 | Check event rate. Count number of visible pulses in 50 traces, three trials: count 8, 9, 6 pulses. 43±9 Hz. Using DCRC1pD. |
| 1130 | Move castle a little closer to fridge and widen lead gap to increase rate. |
| 1130 | Check event rate. Count number of visible pulses in 50 traces, three trials: count 9, 12, 11 pulses. 65±12 Hz. Using DCRC1pD. |
| 1130 | Check event rate. Count number of visible pulses in 50 traces, three trials: count 8, 15, 9 pulses. 65±12 Hz. Using DCRC1pD. |
| 1140 | Estimate that at this event rate, we should drift bias at 3.43 V/min. |
| 1155 | Write new sequence for 8 30-minute series, 180V, drift 3.45 V/min: HVdrift_8X180V_3p45VPM_loopversion_prebias_10_2_dur_30min_flashDCRC_1_4.msl |
| 1207 | Start a sequence of 8 @ 30 min series at HV = 180→284V, rate 3.45V/min, with 10% prebias for 2 minutes, flash at end with 30 min wait. CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (490/400/495)/(420/480/450) uA, Front-End Gains = (2/2/3)/(5/5/5) 1000 BOR, 5Hz InRun randoms, trigger on DCRC1pD threshold = 6, baseline/sample length = 120/28 (standard 16/5), phonon pre-pulse 500 (standard is 500). NaI detector: 800 V → NaI B (dynode terminated) → PS776 → Lecroy 628 Fan In/Out → Ortec 452(Neg input, G=100, shaping=6us, -10V output) → DCRC3 PB, Driver Gains = 1, PhononWaveFormLength = 1024 (512 samples), PhononPrepulseSamples = 512 (512 samples) Use sequence HVdrift_8X180V_3p45VPM_loopversion_prebias_10_2_dur_30min_flashDCRC_1_4.msl |
| 1555 | Fill LN2 cold trap bath. |