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FOC Instrument Science Report 066

FOC Instrument Science Report 066

The f/48 Camera's Detector Quantum Efficiency  10/92
by P. Greenfield

Abstract excerpted from the report:

The Detector Quantum Efficiency (DQE) of the f/48 camera is estimated from 
existing observations intended for other purposes. (There have been no
observations taken with the specific purpose of measuring the DQE of the
f/48 detector, although one such proposal has since been submitted.) Four
filter combinations have been checked, roughly covering 1300 to 3000 A. The
results suggest that the DQE between 1600 to 3000 A appears to be approxi-
mately 60% of that expected (based on prelaunch DQE curves) whereas the DQE
around 1400 A appears to be approximately equal to that expected. Because of
the broadband nature of the filters and other sources of error, the accuracy 
of these measurements is estimated to be +-15% for the 1800 to 3000A range and
+-25% for the 1300 to 1600 A range. No useful estimate was made for the sensi-
tivity beyond 3000 A. The report concludes with an outline of the calibration
proposal to measure the f/48 DQE better (supposing of course, the f/48 camera
is still working).