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2017/02/01 (Wednesday)

	Setup: DIB1/3/4 → 3.2 MHz filters → cables → DCRC55(1)/nothing/nothing
0909	Tower/MC/Coldplate = 39.6/30.2/176.4 mK, Still = 1.0 K / 0.110 mbar, G1/G2 = 163/147 mbar, 1K Pot = 1.70 K / 32 mbar, Main bath = 32.7%. Boil off rate: faster than slow mode.
0916	Fill LN2 cold trap.
1017	Set up to measure Tc's on DIB3. Setup: DIB1/3/4 → 3.2 MHz filters → cables → nothing/DCRC33(2)/DCRC55(1)
	DCRC2 PA is unresponsive to changes in QET bias. (It had seemed dodgy already on 2017/01/26.) pD is an unconnected channel.
1026	Set all DCRC2 QET biases to -10 μA. PB,PC seem to be superconducting. Driver gains = 1x. Zero all DCRC2 phonon channels in preparation for temperature scan.
1052	Applying between 15-25μW to MC scanned a temperature range of 40-80mK.

S101 Critical Temperatures
DIB chan	Side chan	SC → Transition [mK]	Transition → Normal [mK]	Normal → Transition [mK]	Transition → SC [mK]
DIB3 pB	Side 2 PA	71.5	77.9	79.5	75.0
DIB3 pC	Side 1 PA	74.8	78.6	80.2	76.4

1111	Start LHe transfer (MB = 29.2%)
1141	Finish LHe transfer (MB = 90.0%)
1155	Release pressure from MB.
1240	Re release pressure from MB.
1421	DCRC1 seems to be behaving a little better today. Powering it up on DIB1 now causes the base temp to rise to 280mK, but it then begins cooling immediately.
1458	Fridge cooled back to 75mK. Starting up MIDAS DCRC programs with only DCRC1 powered and enabled in ODB. This causes the temperature to immediately rise to 800mK. Telnet session indicates FET heater and LEDs are off (rd 30 = '0000') Changing DCRC1/General/FETHeatEnable to 'y' changes this register to '0100' as expected, but does not reduce heating. However, changing DCRC1/LED/Enable15VPower to 'y' does reduce the heating. This is something Matt had mentioned discovering earlier, but I did not realize these were different settings!
1509	Let's try to get back into our 'standard' setup without heating. Setup: DIB1/3/4 → 3.2 MHz filters → cables → DCRC55(1)/DCRC33(2)/DCRC50(3)
1516	Initial heating observed when powering DCRCs, but it settles down after a minute. All DCRCs responding via telnet.
1518	Enable DCRCs 1-3 in ODB and start MIDAS DCRC programs. Tower temp = 59.6mK and falling.
1521	DCRC3 is railed at -0.5V as it was on 2017/01/27. Let's just try to tune the other SQUIDs for now.
1531	Zap SQUIDs.
1545	Tower = 40.4mK.
1605	Trying to tune SQUIDs. It seems that changing the lockpoint on DCRC1PA affects the modulation curve considerably. Does this make sense? Furthermore, changing the SQUID bias seems to just shift the lockpoint without affecting modulation curve shape. The polarity was still 'Inverted' instead of 'open loop'.
1656	Finish tuning DIB1 SQUIDs.

Channel	SQUID Bias (uA)	Lockpoint (mV)
DIB1 pA	-91.2	-4.3
DIB1 pB	-78.8	-3.3
DIB1 pC	-82.0	-4.8
DIB1 pD	-85.2	-2.7

1714	Fill LN2 cold trap full.