2018/08/08 (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 → DCRC55(1)/DCRC50(3) 1.1kV → NaI B/C → Ortec 452(gain=10, shaping = 6 us, output=10V) / Ortec 575A(gain=10, shaping = 3us) → DCRCX(4) DCRC33(2) → kepco 1kV power supply → HV input |
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| status: Tower stable at base. Took NaI bkg data overnight. DCRCs 1&3 were left off (which is probably why base is a little lower than yesterday). MIDAS crashed at some point after the data finished. | |
| 0915 | Tower/MC/Coldplate = 34.1/28.8/160 mK, Still = 1.1±0.1 K / 0.100 mbar, G1/G2 = 77/82 mbar, 1K Pot = 1.66 K / 40 mbar, MB = 20.9% |
| 0920 | Fill LN2 cold trap full. |
| 0925 | NaI data completed at 0528 and MIDAS failed at some point thereafter. Restart MIDAS. The data looks okay, except there are many points where the pulses become plagued by the 8-bin data shuffle problem in DCRC4. |
| 1030 | Begin LHe transfer @ MB = 18.7% spike in 1K Pot, smaller spikes in Tower and circulation pressure |
| 1041 | Plug HV board back into HV. Daisy chain timing links of DCRCs 1,3,2,4. Enable DCRCs 1,2,3,4 in ODB with DCRC1 as master and others as slaves. Power on DCRCs and start programs. Pulses seen on CDMS detector and NaI. |
| 1047 | Set NaI Ortec amplifier polarities to Pos. This gives upright pulses in the DCRC. |
| 1030 | End LHe transfer @ MB = 86.0% |
| 1151 | Tower = 35.2 mK. It has warmed a bit since powering the DCRCs. |
| 1158 | Start 10 min 0V test dataset with CDMS and NaI detectors running and DCRC2 as HV controller. CDMS detector: Driver Gains = 2x, QET biases = (280/260/305)/(140/295/300) uA, Front-End Gains = 10 NaI detector: 1.1kV → NaI B/C → Ortec 452(gain=10, shaping = 6 us, output=10V, Pos) / Ortec 575A(gain=10, shaping = 3us, Pos) → DCRC4PB/PA, Driver Gains = 1/1, PhononWaveFormLength = 1024 (512 samples), PhononPrepulseSamples = 64 (64 samples) 1000 BOR randoms, trigger on DCRC3pB/C/D threshold = 7/9/8, DCRC4pA/B = 5/5 |
| 1224 | Start 10 min 0V test dataset with CDMS and NaI detectors running and DCRC2 as HV controller. CDMS detector: Driver Gains = 2x, QET biases = (280/260/305)/(140/295/300) uA, Front-End Gains = 10 NaI detector: 1.1kV → NaI B/C → Ortec 452(gain=10, shaping = 6 us, output=10V, Pos) / Ortec 575A(gain=10, shaping = 3us, Pos) → DCRC4PB/PA, Driver Gains = 1/1, PhononWaveFormLength = 1024 (512 samples), PhononPrepulseSamples = 64 (64 samples) 1000 BOR randoms, trigger on DCRC4pA/B = 5/5 |
| 1256 | Set HV = 40V with 15% prebias for 5 min using change_HV_0_to_40_preBias_15_5_DCRC2.msl |
| 1300 | The data from these tests looks good. There are a lot of triggers and they come in bunches of 10s-100s for each DCRC1 and 4. |
| 1307 | HV = 39.962±0.001 V, Vtest = 7.00±0.001 mV, Vdet = 37.16 V |
| 1310 | Start 1 hour 40 V background dataset with CDMS and NaI detectors running and DCRC2 as HV controller. CDMS detector: Driver Gains = 2x, QET biases = (280/260/305)/(140/295/300) uA, Front-End Gains = 10 NaI detector: 1.1kV → NaI B/C → Ortec 452(gain=10, shaping = 6 us, output=10V, Pos) / Ortec 575A(gain=10, shaping = 3us, Pos) → DCRC4PB/PA, Driver Gains = 1/1, PhononWaveFormLength = 1024 (512 samples), PhononPrepulseSamples = 64 (64 samples) 1000 BOR randoms, trigger on DCRC3pB/C/D threshold = 7/9/8, DCRC4pA/B = 5/5 |
| 1420 | Starting at around 12:00 today, circulation pressures began increasing. G1/G2 have climbed from around 80 to close to 140 mbar (sorta flattening out now). This is worrying - this instability may mean we are about to lose cooling power again. Is helium building up in the IVC again?? Turbo on IVC = 0.86 nbar |
| 1433 | |
| 1442 | Start 1hr 40 V background datasets split into 10min subruns, with CDMS and NaI detectors running and DCRC2 as HV controller. CDMS detector: Driver Gains = 2x, QET biases = (280/260/305)/(140/295/300) uA, Front-End Gains = 10 NaI detector: 1.1kV → NaI B/C → Ortec 452(gain=5, shaping = 6 us, output=10V, Pos) / Ortec 575A(gain=10, shaping = 3us, Pos) → DCRC4PB/PA, Driver Gains = 1/1, PhononWaveFormLength = 1024 (512 samples), PhononPrepulseSamples = 64 (64 samples) 1000 BOR randoms, trigger on DCRC3pB/C/D threshold = 7/9/8, DCRC4pA/B = 5/5 |
| 1552 | Bring PuBe source into lab and place on West side of shielding. |
| 1558 | Start 1hr 40 V PuBe datasets split into 10 min subruns, with CDMS and NaI detectors running and DCRC2 as HV controller. CDMS detector: Driver Gains = 2x, QET biases = (280/260/305)/(140/295/300) uA, Front-End Gains = 10 NaI detector: 1.1kV → NaI B/C → Ortec 452(gain=5, shaping = 6 us, output=10V, Pos) / Ortec 575A(gain=10, shaping = 3us, Pos) → DCRC4PB/PA, Driver Gains = 1/1, PhononWaveFormLength = 1024 (512 samples), PhononPrepulseSamples = 64 (64 samples) 1000 BOR randoms, trigger on DCRC3pB/C/D threshold = 7/9/8 |
| 1600 | G1/G2 = 152/147 mbar and continuing to rise slowly. Everything else is stable so far though… |
| 1658 | G1/G2 flattening out at 154/149 |
| 1700 | Turn down HV to 0 V |
| 1701 | Fill LN2 cold trap full. |
| 1705 | Looking at the most recent dataset, it seems like the trigger was dipping a little too far into the noise. Raise DCRCP3 trigger thresholds by 1 ADC each: DCRC3pB/C/D threshold = 8/10/9 |
| 1708 | Start 6 x 2hr 40 V PuBe datasets each split into 10min subruns, with CDMS and NaI detectors running and DCRC2 as HV controller. Using sequence HVscan-40×6-15_5PreBias-30Flash-30wait-2hrData-10minSubRun.msl CDMS detector: Driver Gains = 2x, QET biases = (280/260/305)/(140/295/300) uA, Front-End Gains = 10 NaI detector: 1.1kV → NaI B/C → Ortec 452(gain=5, shaping = 6 us, output=10V, Pos) / Ortec 575A(gain=10, shaping = 3us, Pos) → DCRC4PB/PA, Driver Gains = 1/1, PhononWaveFormLength = 1024 (512 samples), PhononPrepulseSamples = 64 (64 samples) 1000 BOR randoms, trigger on DCRC3pB/C/D threshold = 8/10/9 |
| 1724 | Triggers are still about 50% noise. Raise thresholds again to DCRC3pB/C/D threshold = 9/11/10 |