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2012/10/11

1015 Fed Cricket 3 pellets.
1029 Filled LN2 cold trap.
2000 After looking at pulses from data taken last night, it appears as though the QET biases need some adjustment. Some channels seem to be biased close to the edge of the transition region. Here are the new values (DIB 2 phonon channel C remains unchanged due to strange behaviour):
DIB Channel QET bias [μA] Full range [mV] Minimum QET bias [μA] Maximum full range [mV]
1 A -95 310 -78 420
1 B -85 380 -72 510
1 C -88 320 -75 450
1 D -45 220 -40 280
2 A -49 190 -44 240
2 B -70 120 -60 210
2 D -45 200 -40 270
3 A -44 200 -37 280
3 B -35 150 -31 200
3 C -92 300 -73 410
3 D -80 330 -64 440
2005 Full range is quite small for some channels. This will need to be taken into consideration during the analysis. SQUIDs themselves may be to blame.
It was discovered that incorrect LED settings were used during data acquisition yesterday, namely the current supplied was 0.6 mA rather than -0.6 mA. This has been corrected. However, the detector will need to be flashed again. Set up DAQ to take test data series at 0 V bias and flash detector for an hour, followed by 2 hours for cool down before data acquisition resumes.
2230 Encountered some problems with DIB 1 phonon channel A: consistently jumped to new phi0 cycle, which lies beneath dynamic range. First thought issue was due to SQUID losing lock, but this doesn't necessarily appear to be the case. Problem appears to have been solved by setting driver offset to 0.6 V.
Start test data series 07121011_2228: phonon channels appear to be behaving themselves.
2250 DAQ flashing detector with all 4 LEDs. Appears as though LED settings are correct as mixing chamber temperature has increased to 208 mK.
After approximately three hours, at around 0133 after flashing and cool down, data acquisition will resume: 3 hour-long series at -/+ 4 V bias; followed by 3 hour-long series at +/- 4 V bias. Detector will be flashed for 6 seconds, and DAQ will wait for 20 minutes for cool down between each data series. Once data has been taken, detector will be flashed for 20 minutes, followed by a 2-hour period for cool down.
2355 Fill N2 cold trap full.