2022/03/23 (Wednesday)

Status	Run 76 in progress
Setup	Cable 2/1/3 → diverter/nothing/nothing → DCRC 1/3/4
1000	MC/Coldplate = 28.9/140 mK, Still = 1.16 K / 0.130 mbar / 0 mW, G1/G2= 78/88 mbar, 1K Pot = 18° / 1.67 K / 34±2 mbar.
1115	Goldman = 79.5 mK, MB = 51.1%
1120	Try varying the LakeShore voltage excitation to see how it affects the Goldman temperature readout. 200 uV → 79.5 mK 632 uV → 78.9 mK 2.0 mV → 78.6 mK 6.32 mV → 78.8 mK so it seems that the lowest temperature readout occurs at 2.0 mV excitation, which is pretty high. Typically we set it to something like 20 uV.
1205	Bring PuBe source in paraffin drum into lab, place on north side of shield platform right next to fridge. This is to calibrate NaI detectors with high energy gamma lines.
1210	Try different LakeShore excitations with the H35 thermometer: 2.0 mV → 28.8 mK 632 uV → 29.0 mK 200,63,20 uV → 28.8 K 6.3 uV → VMIX OL so for this thermometer we want excitation no greater than 200 uV (but 6.3 uV is too low)
1240	Trouble connecting to HV supply for NaI array. Return PuBe source to howitzer on 4th floor
1250	Connection problem solved: bad lemo cable for the HV interlock, swapped it out.
1255	Bring PuBe source back into lab.
1300	Conducting NaI calibration with PuBe source. Matt in lab, others have been exiled from lab while source is present. Take 3 minutes of data for each of the 23 NaI detectors one at a time.

Procedure for PuBe calibration of NaI detectors:

Turn off HV on channel n, turn on HV on channel n+1 (GECO2020 on computer)
Disconnect signal cable n+1 from multichannel digitizer at crate, plug it into cable leading to desktop digitizer
Reconnect signal cable n to multichannel digitizer at crate
Update filename with Det# and HV setting (HV setting for each detector is saved in the HV control program) (CoMPASS on computer)
Hit Start button to start data collection. Histogram will start filling. (CoMPASS Plot on computer)
Wait till histogram is finished (it is set to 180 seconds livetime)
Take snapshot of histo using camera button
Repeat (n = 1 to 23)

	As we've seen with NaI data taken previously (with the old cylindrical NaI detectors), there are prominent peaks at 2.1 MeV (n-capture on H-1) and 4.438 MeV (C-12 deexcitation). These seem to be quite linear in the NaI spectrum along with 1.4 MeV from K-41 background (which has been calibrated to x=400 on all the NaI detectors). Also see single-escape and double-escape lines from the 4.4 MeV
	Also seeing a small peak around 7.1 MeV with a Compton spectrum to the left of it extending back to the much larger 4.4 MeV. This may be from a higher C-12 excitation state (though that should probably actually be 7.6 MeV…?). Could be some capture line on some other material in the lab.
1450	Finish PuBe-gamma calibration of NaI array
1500	Return PuBe source to howitzer storage in PAN 443
1626	Begin LHe transfer @ MB = 43.6%
1654	End LHe transfer @ MB = 91.8%