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2020/08/03 (Monday)

Lab in-person: Zach
Virtual partner: Matt

Setup	Run 73. DIB 1/3/4 → Stripline 43/48/41 → pi-filters 1/2/3 → Cable 3/1/2 → nothing/nothing/accessory_interposer → HV_Conn 1/3/2 → HV 1/2 → DCRCX(4)/DCRC55(1)-master; DCRC33(2) → HV control. DCRCs on overnight. Lead/poly shield erected (4 lead walls, 2 poly walls).
1045	Zach Williams body temperature = 98.6
1045	MB = 70.0%
1100	Zach enters lab.
1105	Tower/MC/Coldplate = 51.6/34.4/192 mK, Still = 1.50 K / 0.18 mbar / 5 mW, G1/G2= 453/409 mbar, 1K Pot = 1.64 K / 26±2 mbar.
1111	Begin filling LN2 cold traps.
1119	Finished filling LN2 cold traps.
1120	Zach leaves lab.
1550	Take IbIs for all channels.
1610	Write a new sequence for -10V drifted data. From yesterday's data it looks like we need a higher drift rate at negative bias. HVdrift_neg10V_23p9mVps_multiloop10_nopre_60min.msl
1614	Start a 60 min series at HV = -10V, drifting -0.0239 V/s, no prebias, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,320,370,0)/(0,360,420,420) uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR randoms, trigger on DCRC1pD threshold = 8 Use sequence HVdrift_neg10V_23p9mVps_multiloop10_nopre_60min.msl
1615	Tower = 51.7 mK
1615	Vtest = -0.5 mV, shortly after beginning of drift
1630	Zach Williams body temperature = 98.6
1725	Vtest = -3.3 mV, HV = -95.0 V, drift ends. Lag ratio = 71/60 = 1.18, laggier than it should be.
	Looking closely at the HV slope on the display, it seems that at around 17:00 it started drifting more slowly. Which unfortunately means that the change in gain in the second half of the series will be hard to interpret.
	More precisely: before around 16:48, actual drift rate was 21.5 mV/s, close to what is expected with the usual lag rate (21.7 mV/s). After 16:48, the average actual drift rate was close to 17.5 mV/s.

1845	MB = 59.6%
1910	Write new sequence to drift at -5V, using the faster drift rate that was used for -10V and seemed to work well. HVdrift_neg5V_23p9mVps_multiloop10_nopre_60min.msl
	but will this be correct? Back on July 29 we did -5V drifting at 21.4 mV/s and that worked pretty well. Hmm…
	Let's try -10V again, see if we can get a constant lag rate this time
1947	Start a 60 min series at HV = -10V, drifting -0.0239 V/s, no prebias, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,320,370,0)/(0,360,420,420) uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR randoms, trigger on DCRC1pD threshold = 8 Use sequence HVdrift_neg10V_23p9mVps_multiloop10_nopre_60min.msl
1947	Tower = 51.9 mK
1949	Vtest = -0.45 mV, shortly after beginning of drift
2103	Vtest = -3.0 mV, HV = -95.0 V, drift ends. Overall Lag ratio = 76/60 = 1.27, even laggier than last time!
	This time it looks like it was slow till about 20:48, then got faster.
	More precisely: before around 20:41, actual drift rate was 17.6 mV/s. After 20:41, the average actual drift rate was 21.6 mV/s, close to what is expected with the usual lag rate (21.7 mV/s). So it looks like there are two characteristic lag rates, which I guess change back and forth at random times. The good “fast mode” has a lag ratio of 1.11; the bad “slow mode” has a lag ratio of 1.36. That's like a 1-second overhead versus a 3.6-second overhead per 10-second step.

2324	Start a 60 min series at HV = -10V, drifting -0.0239 V/s, no prebias, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,320,370,0)/(0,360,420,420) uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR randoms, trigger on DCRC1pD threshold = 8 Use sequence HVdrift_neg10V_23p9mVps_multiloop10_nopre_60min.msl
2325	Tower = 51.6 mK
2325	Vtest = -0.5 mV, shortly after beginning of drift
	cripes, this is another one that started fast then the lag got worse later.
0039	Vtest = -3.1 mV, HV = -95.2 V, drift ends. Overall Lag ratio = 75/60 = 1.25, too high.
	Actually analysis of the rate of HV increase looks different this time. Drift rate starts around 22.0 mV/s (lag ratio 1.09), then gets steadily worse, ending at around 16.0 mV/s (lag ratio 1.49).