2016/09/17 (Saturday)

Previous Day

	Status: LHe in bath, mixture circulating, DCRC1 and DCRC3 powered on and connected through HV setup EBoxDIB 2/3 → 3.2 MHz filters → Cables → remapping board I/remapping board II → HVside2board “DIB1”/“DIB2” → DCRC55(1)/50(3). Remapping boards have all possible lines switched off. .
	Baked using IR LEDs for 12 hours overnight
1006	MC(Cernox)/Tower/1K Pot = 60 mK/93 mK/1.44 K,P2 = 2.2 mbar G1/G2 = 108/108 mbar, MB = 17.1%
	It appears that at end of bake fridge temperatures were at 564 mK, but dropped quickly to current 93 mK.
1011	Tweak 1K Pot open a bit. Also fill LN2 cold traps full.
1050	After seeing some potential pulses in DCRC1 Qo (our readout channel), adjust the charge trigger threshold from 60 to 3400 (is it usually this high?) start seeing some pulses that look like damped oscillations. Note that sinusoidal noise from yesterday is still present, which might be affecting the shape of the pulse as well.

Post 12 hour IR bake, 10V applied to DCRC1, 0V on DCRC3.

1054	1K Pot at 1.5 K/ 4.5 mbar. Tweak needle valve again.
1055	Commence LHe transfer (12.5%).
1114	Start taking a 15 minute 10V DCRC1/0V DCRC3 data series triggering on DCRC1 Qo (threshold 3400) with 2000 initial randoms (because I forgot to change it back to 1000).
1145	Commence 6 minute minibake with UV LEDs on both DCRCs set to -0.8 mA current, during this time check for LED voltage pulses on PA and PB. All pulses look fine except DCRC3 PB channel is flatlined, when it should be showing pulses, or at least noise.Set ADCoffset on DCRC3 PA and PB, and noise returns to both channels.
1155	Notice a high pitch noise, not loud but super annoying. I think its the turbo pump. Turn off the turbo pump.
1201	Turn off DCRC1 Qo 10V Bias, and notice increase in event rate (still on 3400 Qo charge trigger threshold). Seeing lots of noisier pulses, that still have the ringdown shape as previous pulses. They occur frequently enough to get several of them in a 30ms window (not possible with previous 10V pulses), but they do seem random in time.

Post 6 minute UV bake, 0V applied on both DCRCs

1216	Commence 2 hour long UV bake (-0.8 mA).
1235	End LHe transfer (90.5%).
1242	Let pressure out of main bath.
1402	Back from gym. 1K Pot is low 1.45 K / 2.4 mbar, so tweak needle valve again. Bake is still going on with tower temperature at 400 mK.
1435	Perhaps its because the tower temperature is at 183 mK and still falling from the 2 hour UV bake, but the pulses at 0V look terrible. Maybe I shouldn't be surprised?.

Post 2 hour UV bake (-0.8 mA). 0V on DCRC1 and DCRC3

1438	Applying 10V to DCRC1 Qo certainly helped. Pulses are back to looking as they originally had, though some might be a bit noisier.

Post 2 hour UV bake (-0.8 mA). 10V on DCRC1 and 0V on DCRC3

1456	Tweak needle valve again (1K Pot had been at 1.44 K / 2.0 mbar)
1458	With fridge temperature returning to the 90 mK range, start taking a 15 minute 10V DCRC1/0V DCRC3 data series triggering on DCRC1 Qo (threshold 3400) with 1000 initial randoms .
1516	After stopping run, look at pulses. I see 116 Hz sinusoidal noise with 0.7 Vpp (not sure why the picture shows a higher Vpp, this was what it was normally reading). It looks like you can see small pulses on top of noise.

Noise after last data taking

1522	After setting the Qo bias to 0V the noise remains but is no longer as significant. I wish I could look more into this, but its time to go.
1526	Switch back to IR LEDs and commence 12 hour IR bake (+0.6 mA).
1530	Fill LN2 cold trap full.
1531	1K Pot at 1.61 K / 13 mbar, but IGH plots show its still falling. Tweak needle valve one last time.
1537	G1/G2 = 223/215 mbar, P1=0. 22 mbar, 1K Pot = 2.20 K / 1 bar (off charts) and falling, Tower temperature at 494 mK and still slowly rising due to bake. DCRCs are still powered on in HV setup. He level at 88.3%.

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