2019/06/06 (Thursday)

Previous Day

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
0910	Tower/MC/Coldplate = 45.7/31.1/178 mK, Still = 1.02 K / 0.095 mbar, G1/G2 = 178/169 mbar, 1K Pot = 1.63 K / 22 mbar. MB = 39.5% coldplate and still are reading in their “low” modes for whatever reason
	Tower temperature continues to fall linearly, slowly
0915	Fill LN2 Cold trap bath
	Python webcam app watching recovery overnight failed with this message:

Traceback (most recent call last):
  File "webcamAutomater.py", line 99, in <module>
    if args.save_images: make_timestamped_copy()
  File "webcamAutomater.py", line 45, in make_timestamped_copy
    os.rename(fileName_old, fileName_new)
OSError: [Errno 2] No such file or directory

	Last file saved was cam1_image_20190605_170442.png
1000	Begin purging Ebox bag with N2 boiloff gas
1245	Check channels. DCRC4pB was railed. Looks like maybe its 370 uA QET bias is too low (maybe because the tower is still cooling). Adjust it up to 400 uA.
	Let's try more data. We have the Ebox purge gas going, so we can see if leakage current improves. And let's try the sequence that does just one series, in case the super-long sequence file somehow slows down the DAQ.
1302	Start a 25 min series at HV = 300→400V, rate +3.9V/min with 5% prebias for 1 minute, flash at end with 30 min wait. CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (420/400/440)/(420/400/450) uA, Front-End Gains = (2/2/3)/(5/5/5) 1000 BOR and 1000 EOR randoms, , trigger on DCRC1pB/C/D threshold = 7/7/7. Use sequence HVdrift_300V_3p9VPM_prebias_5_1_dur_25min_flashDCRC_1_4.msl
	now it looks like the voltage is ramping up at a rate of about 2 s/V. Yesterday it was 4 s/V. (Should be 1 s/V.)
	Leakage is dramatically lower, Vtest maximum <10 mV, c/w 34-53 mV yesterday.
	During ramp-up and ramp-down Vtest has a few weird steps, didn't see those last night.

noise width is not great for this series, around 40 eVee. Though maybe saturation is making the calibration wrong.
there's a huge number of events around 200-300 eVee. These look like junk but hard to cut out - traces are sorta wavy. “Breakdown noise” maybe.

1508	Start LHe transfer @ MB = 30.7%
1550	End LHe transfer @ MB = 100.5% (!)
1655	Fill LN2 cold trap bath
	Let's try a lower bias series.

[fritts@jiajin /home/hep/cdmssoft/scdmsDAQ/MidasDAQ/online/scripts/pysequencer]: python HVscan.py -iDCRC 2 -HVs 200 -HVcalFile HV_calibrations/HV_DCRC2_control_cals_440V_190603.txt -HVdriftRate 0.065 -HVpreBias 10/2 -tSeries 50 -DCRCs2Flash 1,4 > ../../sequencer/HVdrift_200V_3p9VPM_prebias_10_2_dur_50min_flashDCRC_1_4.msl

1707	Start a 50 min series at HV = 200→400V, rate +3.9V/min with 10% prebias for 2 minutes, flash at end with 30 min wait. CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (420/400/440)/(420/400/450) uA, Front-End Gains = (2/2/3)/(5/5/5) 1000 BOR and 1000 EOR randoms, , trigger on DCRC1pB/C/D threshold = 6/6/6. Use sequence HVdrift_200V_3p9VPM_prebias_10_2_dur_50min_flashDCRC_1_4.msl
	As earlier the rampup seems to be taking 2 s/V.
1710	MB = 96.0 %
1722	Try reducing trigger thresholds to 5/5/5 for about 30 seconds. Seems to low, so raise them to 6/6/6 again.
1725	Vtest ~= 5 mV. HV = 228 V.
	In this series and the early one today you can clearly see Vtest react to the HV updates, spiking up as soon as the HV is updated (about every 12 seconds) and then settling quickly, spiking to 6 mV then settling to 5 mV
1859	Start a 50 min series at HV = 200→400V, rate +3.9V/min with 10% prebias for 2 minutes, flash at end with 30 min wait. CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (420/400/440)/(420/400/450) uA, Front-End Gains = (2/2/3)/(5/5/5) 1000 BOR and 1000 EOR randoms, , trigger on DCRC1pB/C/D threshold = 6/6/6. Use sequence HVdrift_200V_3p9VPM_prebias_10_2_dur_50min_flashDCRC_1_4.msl
2217	Start a 50 min series at HV = 200→400V, rate +3.9V/min with 10% prebias for 2 minutes, flash at end with 30 min wait. CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (420/400/440)/(420/400/450) uA, Front-End Gains = (2/2/3)/(5/5/5) 1000 BOR and 1000 EOR randoms, , trigger on DCRC1pB/C/D threshold = 6/6/6. Use sequence HVdrift_200V_3p9VPM_prebias_10_2_dur_50min_flashDCRC_1_4.msl

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