2019/06/27 (Thursday)

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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 Three walls of the lead/poly shield are up.
	It's hard to see the 0.16 keV M-shell line in recent data. Let's try a lower trigger on Side1pF only (DCRC1pD).
0732	Start an 88 min series at HV = 180→400V, rate 2.49V/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. Use sequence HVdrift_180V_cal0612_2p49VPM_prebias_10_2_dur_88min_flashDCRC_1_4.msl

Written event rate 68 Hz, write efficiency only 39%

0852	Fill LN2 cold trap bath
0924	Tower/MC/Coldplate = 38.9/29.3/199 mK, Still = 1.40 K / 0.18 mbar / 6mW, G1/G2 = 221.9/207.6 mbar, 1K Pot = 1.62 K / 20 mbar. MB = 68.2%
1118	Lower PuBe source into shield near detector for more neutron activation
1348	PuBe source removed after exactly 2.5 hours
1355	PuBe source returned to room 443 for storage
1410	Check event rate by counting number of pulses seen in random traces. Count 17 in 50 3.3 ms traces = 103±25 Hz, pretty high.
1515	Check event rate by counting number of pulses seen in random traces. Count 17 in 50 3.3 ms traces = 103±25 Hz, still pretty high.
1530	Something is wrong with the LN2 Dewar. We are getting very little pressure coming out of the Vent, and sometimes nothing at all out of Liquid, sometimes a very slow trickle. Tried heating the top with a heat gun in case there's a plug of ice, but didn't help. Maybe somehow a bunch of ice got into it. Another possibility: the Vent was left open too wide for the purge, and the pressure is just too low.
1530	Fill LN2 cold trap bath using 5L transfer Dewar.
1545	Start an 88 min series at HV = 180→400V, rate 2.49V/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. Use sequence HVdrift_180V_cal0612_2p49VPM_prebias_10_2_dur_88min_flashDCRC_1_4.msl
1855	Create a sequence to do three of these series in a row (hopefully it will work and not lag).

python HVscan.py -iDCRC 2 -HVs 180,180,180 -HVcalFile HV_calibrations/HV_DCRC2_control_cals_440V_190612.txt -HVdriftRate 0.0415 -HVpreBias 10/2 -tSeries 88 -DCRCs2Flash 1,4 > ../../sequencer/HVdrift_3X180V_cal0612_2p49VPM_prebias_10_2_dur_88min_flashDCRC_1_4.msl

1905	Start sequence of 3 @ 88 min series at HV = 180→400V, rate 2.49V/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. Use sequence HVdrift_3X180V_cal0612_2p49VPM_prebias_10_2_dur_88min_flashDCRC_1_4.msl

1905

Start sequence of 3 @ 88 min series at HV = 180→400V, rate 2.49V/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.
Use sequence HVdrift_3X180V_cal0612_2p49VPM_prebias_10_2_dur_88min_flashDCRC_1_4.msl

Looking at the Vtest pattern, it's very clear that the sequence is progressing significantly more slowly with this triple-series sequence than with a single-series sequence. Lame!
103 dumps, rather than the usual 94 dumps
Vtest above; note that second sequence above is slower than first

2135	Stop sequence after first series.
2135	Create a new sequence to do one 180-400V series using loops and ODBINC commands, by editing the sequence we've been using lately. Call it HVdrift_180V_2p49VPM_loopversion_prebias_10_2_dur_87min_flashDCRC_1_4.msl
2005	Start an 87 min series at HV = 180→400V, rate 2.49V/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. Use sequence HVdrift_180V_2p49VPM_loopversion_prebias_10_2_dur_87min_flashDCRC_1_4.msl

93 dumps, so this version of the sequence with loops may be slightly faster.

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