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2021/09/13 (Monday)

Lab in-personnel: Giulia and Matt

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
0832	Tower/MC/Coldplate = 90.5/34.6/195.1 mK, Still = 1.38 K / 0.070 mbar / 0 mW, G1/G2= 285.5/260.2 mbar, 1K Pot = 1.56 K / 10±1 mbar. MB = 36.4%.
0839	Fill LN2 cold trap bath
0842	At 10kHz noise in DCRC3qI/qO/DCRC1qI/qO = 11/2.1/2.7/36 8e-6. This is q3/q1/q4/q2 At 3kHz (peak) noise in DCRC3qI/qO/DCRC1qI/qO = 79/15/41/350 e-6.
	Noise is slightly higher than yesterday.
1011	Start 45 min series of +10V/0V, +12V/0V (bias applied after 60 sec and after 4min increased it to +12V), with 1000 beginning randoms, trigger threshold 80/35/30/200 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.

07210913_1011

1135	Start 45 min series of +10V/0V (bias applied after 60 sec), with 1000 beginning randoms, trigger threshold 80/30/30/180 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.

07210913_1135

1255	Turn on MC heater to 1200 uW
1330	Tower/MC = 1.145/1.163 K, seems to have mostly settled. G1/G2 = 440/404 mbar, Still = 0.15 mbar
1335	Start 45 min series of +10V/0V (bias applied after 60 sec), at elevated temperature, with 1000 beginning randoms, trigger threshold 80/30/30/150 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.

07210913_1335

1425	Increase MC heater to 2000 uW
1435	Temperature is a bit unstable. Turn off MC heater.
1515	Begin LHe transfer @ MB = 26.9%
1554	End LHe transfer @ MB = 92.7%
1605	Tower = 184 mK. Rose a bit after the transfer.
1608	Start 45 min series of +10V/0V (bias applied after 60 sec), with 1000 beginning randoms, trigger threshold 80/30/30/150 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.

07210913_1608