2016/06/10 (Friday)

Previous Day

Setup	DIB1/2 → cables → Dsub filters → DCRC55/50. DCRCs powered.
	taking 2-hour runs overnight, last flash at 5:40. Sequence finished according to DCRC Control.
0855	MC/Tower/Cold Plate: 33.3/44.3/181 mK. Still: 1.16 K / 95 μbar. G1/G2: 105/110mbar. 1K Pot: 1.55K / 4.5 mbar. Main bath = 40.4%
	Tower stayed between 44 and 45 mK overnight. Over the last four data runs it was lowest during the first, highest during the second, then cooled a little in the 3rd and 4th.
	1K Pot pressure not bad overnight, falling from 6.5 mbar to 4.5 mbar in the last 10 hours
0905	Fill LN2 cold trap bath
1240	Flash detector using DCRC control, to neutralize after the last 2-hour run. (Actually it's a 6-minute bake, left the default settings: ON/OFF = 0.1/5 sec, Duration = 0.1 hours)
1350	Unpower DCRCs and attach HV Board according to the 4Q HV setup laid out in the Run 58 summary.
1410	With Variac powered, but HV Power Supply unpowered, we are seeing a ~60Hz triangular wave on the charge channels for both DIBs. Unplugging the coax cable from the HV board causes the wave to become smaller with respect to the white noise, but it's still present at ~25mVpp. Unpowering the variac has no effect. Unpower both DCRCs to see if that helps.
1430	Power both DCRCs again. Troubleshooting outlined below: (All Vpp given for DIB1 Qo)

Triangular wave still present at ~25mVpp.
When attaching the coax from the unpowered HV supply to the HV board, the Vpp increases to ~2.5Vpp.
When powering on the variac, the Vpp increases to ~3.5Vpp.
When powering on the HV supply, the Vpp increases to ~7Vpp.
Unpowering both Variac and HV supply, and unplugging the variac from the wall causes the Vpp to drop to ~150mVpp.
Detaching the coax cable from the HV Board and touching it to the chassis of the HV board causes the Vpp to increase to ~250mVpp.
Disconnecting the coax from the HV supply, and connecting the other end to the HV board, and using a 9V battery to apply a voltage does not produce any pulses or have any effect on the noise.

1500	Zap SQUIDs for the heck of it.
1515	Commence LHe transfer (30.6%).
1515	Reestablish timing link, and check charge channels. Triangular noise still present.
1540	Try biasing charge channels to 4V with the DCRCs. Pulses present above the noise. This is with nothing plugged into the HV coax, so this is the lowest noise state.
	With HV input plugged into the HV supply (with the supply off) you can't see the pulses above the large noise.
1550	Cease LHe transfer (93.1%).
1650	Let pressure out of main bath.
1655	Before switching back to IZIP mode, disable DCRC1. Unpower DCRC1. Noise still present on DIB2. Unplug cable to EBox from the back of the HV board → The noise goes away on DIB2. Plugging this cable back into the back of the HV board causes the noise to reappear.
	Lifting the HV Box and unpowered DCRC1 up off the top of the Break Out Box causes the noise to go away, but when we try to figure out if it's the DCRC connection to the box or if it's the HV Box touching the Break Out Box, we can't get the noise to go away again.
	Removing the 3.2MHz filter has no effect. Swapping the order of the gender swapper and the 3.2MHz filter has no effect.
	Switching the cable from the HV box to the EBox with another shielded cable has no effect.
	Touching the shell of any one of the DSUB connectors on the HV Box to the metal chassis of the HV Box causes the triangular noise to go away. Boom!
1725	Repower DCRC1 attached in the IZIP setup: EBox → Cable → Gender Swapper → Filter → DCRC. Pulses look good.
1735	Fill LN2 cold trap full.
	1K Pot has been pretty steady at 5mbar for several hours. However, in preparation for the weekend, open 1K Pot needle valve 16th of a turn.
1745	1K Pot has settled around 1.73K and P2 reads 65mbar.
1800	Start 44 hours of 30 min Ba series bias sweeps at +/+1 V to +/+13 V and -/-1 V to -/-13 V, then +/+5V to +/+13V and -/-5V to -/-13V in increments of 1 V with 30s flash and 25min cooldown in between. Triggering on DIB1 Qo at 40ADC bins. 1000 randoms before and after.
1805	Place Ba source at back of fridge near where top of shield would be for overnight Ba runs.

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