Monday, December 05, 2011

Noise v. Detector Bias

Noise measurements using all-destructive scans have been collected over a range of detector bias values.

Values reported are measures of noise obtained though the 'many pixel' method used at UofR.  A set of 200 all-destructive reads is obtained at each bias, with consecutive scans differenced and analyzed to yield an areal standard deviation.  This sdev is divided by root-2 and reported as read noise here.

FWIW, the plot below shows a not-terrible exponential fit to the data.  The blackbody was switched off during this measurement, but there is probably some low-level light leak in the test dewar so it may be worth spot-checking this data when the device is taped off for a dark current measurement.




Bias values are relative to VDDUC/VRST setting of -2.221V.  VDET values are more negative than VDDUC/VRST, but biases are plotted as magnitude.  

Relevant log pages:  EXES Vol.3, pp.94 - 95

Data collected at T = 7K, with a three second scan time.  Values are in raw DN (1DN ~ 35 electrons)



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