Tolerance Analysis of FIMS Optical System

Abstract

Far-ultraviolet IMaging Spectrograph (FIMS) is the main payload of the first Korean scientific satellite, KAISTSAT-4, which will be launched in 2002. The optical system of FIMS consists of parabolic cylinder mirror, slit, ellipsoidal reflection grating, and MCP to get spatial information as well as spectral information. Allowed ranges of manufacturing and positioning error are derived for each optical components to achieve the astronomical goals. In the procedure, graphical simplification is dedicated to understand sensitivity table and to derive range and precision of manipulation for each optical component. The result shows that precision of 15 for linear and of 2 for angular manipulation fulfills optical requirements.