2018/09/27 (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 → DCRC55(1)/DCRC50(3) 1.1kV → NaI B/C → Ortec 452(gain=5, shaping = 6 us, output=10V) / Ortec 450(gain=5, shaping = 5 us integration, Neg input) → x10/x10 attenuator → DCRCX(4) DCRC33(2) → kepco 1kV power supply → HV input |
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| status: | background -125V data overnight, tower = 30.0 mK |
| 0940 | Tower/MC/Coldplate = 30.0/30.6/184 mK, Still = 0.0 mW / 1.3±0.1 K / 0.090 mbar, G1/G2 = 124/124 mbar, 1K Pot = 1.60 K / 18 mbar, Turbo on IVC = 0.86 nbar, MB = 72.2% |
| 0945 | Fill LN2 cold trap. |
| 1005 | Stop sequence after a flash. Need to fill LN2 Dewar so we should wait till that's done before we bias the detector again. |
| 1145 | Move PuBe source into lab. Place barrel at South wall to do NaI calibration. |
| 1305 | Remove 22Na source from safe and place on south shield wall for NaI calibration. |
| 1340 | Move PuBe source barrel to its standard position behind lead wall outside of the west shield wall |
| 1400 | Return 22Na source to safe. |
| 1405 | After monkeying around with the NaI setup, determine that the optimal arrangement is the following: 1.1 kV (for real) → NaI B/C (dynodes terminated) → Ortec 450(Neg input, gain=5, shaping = 5 us integration, output=+10V)/ Ortec 575A(Neg input, gain=5, shaping = 3 us) → x10/x10 attenuator → DCRCX(4) PB/PA This is what we'll use from here on out. |
| 1419 | Start 8x2hr PuBe series at HV = -125 V with 15% prebias for 5 min, split into 10 min subruns, with CDMS and NaI detectors running and DCRC2 as HV controller. Using sequence HVscan-125×8-15_5PreBias-DCRC2_250V-30Flash-30wait-2hrData-10minSubRun.msl CDMS detector: Driver Gains = 2x, QET biases = (280/260/305)/(140/280/295) uA, Front-End Gains = (10/10/10)/(10/15/10) NaI detector: 1.1 kV (for real) → NaI B/C (dynodes terminated) → Ortec 450(Neg input, gain=5, shaping = 5 us integration, output=+10V)/ Ortec 575A(Neg input, gain=5, shaping = 3 us) → x10/x10 attenuator → DCRCX(4) PB/PA, Driver Gains = 1/1, PhononWaveFormLength = 1024 (512 samples), PhononPrepulseSamples = 64 (64 samples) 1000 BOR randoms, trigger on DCRC3pB/C/D threshold = 7/10/9 Note the correct NaI bias and the new NaI amplifier arrangement. |
| 1655 | Fill LN2 cold trap bath |