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2009/12/01

Run diary

Time Task
09:42 Fill N2 cold trap
15:53 phC noise debugging; take data run001-007 with different frontend gains.

Matlab .fig files

Noise RMS current above 100 Hz

Frontend Gain 1 2 3 4 5 6 7
IRMS (100 nA) 0.1484 0.1523 0.1590 0.1719 0.1979 0.2373 0.6478

Considering the QET biasing current are in the order of 10 uA, the heating effect from the high frequency current is negligible.

Time Task
17:43 Judging from the peaks around 50 kHz on the noise PSD of phC, orange ground is the best, floating is the next, both the Cu rods and the black grounds made things worse. That being said, the effect is small.
17:49 Fill N2 cold trap
18:30 Transfer liquid He

Data list

Settings for run001 to run007
Output Gain=1, Feedback Null=0, Driver Offset=0, SQUID Bias =76.63, Lockpoint=2.38, QET Bias =-1480, MC T=35.6mK, Qi=0, Qo=0
Time Run # Channel Settings Measurement
15:56 1 C Frontend Gain=1 Noise psd
15:56 2 C Frontend Gain=2 Noise psd
15:56 3 C Frontend Gain=3 Noise psd
15:56 4 C Frontend Gain=4 Noise psd
15:56 5 C Frontend Gain=5 Noise psd
15:56 6 C Frontend Gain=6 Noise psd
15:56 7 C Frontend Gain=7 Noise psd