STRAY-LIGHT ISSUES FOR BACKGROUND-LIMITED FAR-INFRARED TELESCOPE OPERATION

The detector in a background-limited infrared telescope receives less power due to the thermal emission from telescope components than from the background. The Arizona Program for the Analysis of Radiation Tran sfer has been used to set the temperature of the telescope components so that each component contributes less than 10(-13) W of thermal powe r to the detector in the Space Infrared Telescope Facility long-wavele ngth configuration. The secondary mirror assembly, seen from the detec tor is the most critical emitter even at 3 K.