2018/08/09 (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 575A(gain=10, shaping = 3us) → DCRCX(4) DCRC33(2) → kepco 1kV power supply → HV input |
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| status: Took SiHV+NaI PuBe data overnight. But it looks like it stopped - should have taken 6 2-hour sets but stopped in the middle of the 3rd one, last series written was last night at 23:47. But it doesn't look like MIDAS crashed… and it says the sequence finished. It appears that the sequence kept going but the data did not get moved to /byseries, it's still in /livedata. So the lazy logger must have failed. |
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| 0950 | Tower/MC/Coldplate = 34.5/29.5/164 mK, Still = 1.1±0.1 K / 0.090 mbar, G1/G2 = 117/114 mbar, 1K Pot = 1.65 K / 34 mbar, Turbo on IVC = 1 nbar, MB = 55.8% |
| overnight G1/G2 drifted down from 130→120 mbar. Pot quite stable. | |
| 1005 | Fill LN2 cold trap bath. |
| 1225 | Stop and restart MIDAS DAQ, trying to see if the logger starts working again to move data from /livedata to /byseries. |
| 1535 | Look at DCRC3pC: this channel has had strong oscillations. Try lowering QET bias 295→285. There are still some oscillation after-peaks but only at higher amplitudes, above 0.5 Vpp. At 295 the after-peaks are strong even in much smaller pulses. |
| 1543 | 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)/(140/285/300) 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 |
| 1647 | Looked at data - a lot of after-peaks in DCRC3pC still, I guess because when I adjusted the QET bias the HV bias was still 0V. So for now just turn off triggering on DCRC3pC because I don't want the double-triggers. |
| 1650 | Vbias = 40.00 V, Vtest = 4.97 mV, → Vdetector = 38.0 V |
| 1655 | Fill LN2 cold trap bath |