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2012/02/13

0925	Filled LN2 cold trap.
0933	Tower temperature: 78 K; 1K pot: 1.38 K; G1: 45 mbar; G2: 60 mbar

1157	Tested noise of DCRC33 with high voltage interface board. Interface board DB50 connector shells shorted, board shielded with Al case and u tape, DCRC digital ground grounded to chassis.
	A few spikes around a few tens of kHz was removed by turning off the fridge side lights.

1223	Start taking data 07120213_1223_F0001. +10V is applied to the back side of crystal. DCRC33 only, 0V, trigger on Qi OR Qo at 40 ADC bin. Ba source 6“ below top edge of mu shield.

First Look at data using HV interface board; +10V applied to back side of crystal w/ Ba-133.

500

500

1627	Tried turning up the voltage of the Kepco power supply, tower temperature jumped at around 20V, charge signal baseline waggled too. Reduced bias to 15V. Temperature dropped and charge baseline was getting stable.
1639	Tower temperature rose to 81.7mK at 15V bias from 78mK at 0V bias. Probably we will not able to use a high voltage.
1640	Turn off Kepco power supply. Temperature starts to drop.
1709	Tower temperature 78.7mK. Set Kepco to 20V and then turn on the power supply. The charge noise jumped up and tower temperature spiked. Does the crystal break down at 20V?
1715	Removed the Cu tape between the Al case and ebox, the noise got slightly worse.
1815	Had a look at the synchronization of the boards with different trigger thresholds. It's easier to see if they are synchronized by diabling the trigger from one board.
1843	Begin LHe transfer (18%).
2207	Tower temperature 123 mK and keeps fluctuating. Is due to the hi pressure in the bath?