DEAD AND NOLSY CHANNEL UPDATE
October 23, 1989

R. D. Cohen, E. A. ßeaver, and V. T. Junkkarmen
UTniversity of California, San Diego
CAL/FOS064


Five series of exposures of 900s each were taken witb the Blue (F7)
detector of the FOS as part of the Orbit 7 tests on 28 March, 30
March, 7 August, and 22 August, 1989. Each 900s exposure consisted of
30 30s frames. The only changes rnade to tbe discrirninator settings
in the PR.OMs were tbose of Tables 5 and 7 in CAL/FOS-~50.

One series of dark exposures of 1140s total was taken with the Red
(F12) detector of the FQS as part of the Orbit 8 tests on 29 March
1989. The exposure consisted of 38 30s frarnes Another series of live
dark exposures of 24 slices eacb and 2040s total was taken with the
Red (F12) detector of the FOS as part of the Noise 7 tests on 31 March
1989. The only changes made to the discriminator settings in the PROMs
were those of Table 8 in CAL/FOS-50.

Noisy channels were selected as those where the total counts detected
in a given exposure (900s or 1140s) exceeded the threshold where the
probability of occurrence of a channel with as large a total c.ount
rate or greater from tbe total array was less than one half.