Properties of the Detector System for the International Ultraviolet Explorer Satellite

Abstract

This chapter elaborates the properties of the detector system for the International Ultraviolet Explorer (IUE) satellite. The IUE satellite is an ultraviolet astronomical observatory intended primarily as an international research facility for the use of guest observers. The detector for the scientific instrument consists of a secondary electron conduction (SEC) camera fiber optically coupled to a proximity focused wavelength converter. For the acquisition camera, an SEC tube only is used. The SEC camera tube was selected because of its characteristics of long integration time, good target gain, adequate target capacity, large dynamic range, and low noise. The proximity focused diode was chosen because of its flat input faceplate enabling an ultraviolet transmitting window to be used. The SEC camera tube that has been selected for the IUE detector is the Westinghouse WX32224. It is suggested that as the overall performance of the IUE camera is determined by that of both the SEC tube and the converter, it is essential that the modulation transfer function of the converter should be as high as possible.