INSTRUMENT SCIENCE REPORT CAL/FOS-O11
SPACE TELESCOPE SCIENCE INSTITUTE	


Scattered Light Background Perpendicular to the
Dispersion - Preliminary Version  (FOS Calibration #19)
	
AUTHOR: D. Lindler and R. Bohlin	
DATE: January 1985

ABSTRACT



An analysis of the scattered light perpendicular to the direction of
spectral dispersion was done for all FOS dispersers using data taken
during the thermal vacuum calibration in July 1984 and during ambient
calibration in August 1984. The intensity of the scattered light is
less than 0.5% of the intensity of the spectrum at positions 1500
microns above or below the spectrum on the photocathode.


A spectrum that 15 not completely understood appeared on both tubes
when the blank aperture and grating L65 were in place.