2021/08/24 (Tuesday)

Lab in-personnel: Giulia and Derek

Status	Run 74 in progress. First cooldown after IVC rebuild.
	Tower thermometer is reading high, probably this is a thermometer problem and the actual temperature is much lower. High noise in some of the charge channels.
	Setup: DIB1/2+acc → SL 41/43 → 3.2 MHz filters → cables 2/3 → nothing/Source_mover_board+HV_diverter_board → DCRC50(3)/55(1). Kepco 40V supplye → HV BNC. Lead shield erected, 4 walls. Currently both DCRCs are on.
	Position of Am source: y = 0.0 mm
0841	Tower/MC/Coldplate = 137.5/34.0/191.2 mK, Still = 1.39 K / 0.070 mbar / 0 mW, G1/G2= 300.5/278.9 mbar, 1K Pot = 1.57 K / 20±1 mbar. MB = 28.9%.
0854	Fill LN2 cold bath.
0858	Start 45 min series of 12V/0V (bias applied after 60 sec), with 1000 beginning randoms, trigger threshold 100/50/50/230 on DCRC3qI/qO/DCRC1qI/qO, 5Hz in-run randoms, with 1.6384 ms pulses (8192 length) and 400 us prepulse (500 length). Use Sequencer script r74_takeandflash_dcrcbias.msl. This flashes for 30 seconds at end of series.

Series 07210823_1408 the peak here is much lower than the previous 10 V series.

Series 07210823_1629 trying with - 10 V on side two, no real change.

Series 07210824_0858 moving to 12 V the peak is much larger than 10 V, but still far lower than the previous 12 V series.

1350	Start 45 min series of 14V/0V (bias applied after 60 sec), with 1000 beginning randoms, trigger threshold 90/40/50/215 on DCRC3qI/qO/DCRC1qI/qO, 5Hz in-run randoms, with 1.6384 ms pulses (8192 length) and 400 us prepulse (500 length). Use Sequencer script r74_takeandflash_dcrcbias.msl. This flashes for 30 seconds at end of series.
1321	Begin LHe transfer @ MB = 21.1 %
1359	End LHe transfer @ MB = 87.7 %
1529	At 10kHz noise in DCRC3qI/qO/DCRC1qI/qO = 19/3.0/2.5/52 8e-6. This is q3/q1/q4/q2 At 3kHz (peak) noise in DCRC3qI/qO/DCRC1qI/qO = 480/29/50/850 e-6.
	Noise is slightly higher yesterday.

Series 07210824_1350 with 14 V the peak is again larger than 12 but doesn't show signs of fallout, the sparse area is likely due to the end of the LHe transfer.

1558	Start 45 min series of 0V/-16V (bias applied after 60 sec), with 1000 beginning randoms, trigger threshold 85/45/55/260 on DCRC3qI/qO/DCRC1qI/qO, 5Hz in-run randoms, with 1.6384 ms pulses (8192 length) and 400 us prepulse (500 length). Start sequence with Start button.
1644	Dial HV down to 0V and flash for 10 minutes with DCRC1&3 LEDs.

Series 07210824_1558, tried -16 V on side 2, immediately saw break down noise, dialed it down to -14 and the series returned to normal triggered data.

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