Elimination of Corona and Related Problems with Astronomical Image Tubes

This chapter discusses the elimination of corona and related problems with astronomical image tubes. It summarizes a variety of techniques utilized that, taken together, eliminate corona and voltage leakage problems. It is found that nearly every intensifier system that exhibits corona emission or other high voltage leakage problems does so because, outside of an obvious component failure, it has one or both of the following characteristics: There exists a dielectric material that insulates a component maintained at high voltage from its surroundings, but the outer surface of the dielectric is at an ill-defined or totally “floating” Potential; therefore, a charge builds up on the outer surface of the dielectric until a general corona discharge, or arc, is created. There exists a direct leakage path along the boundary of dissimilar dielectric materials that provides electrical conduction between the component and its surroundings.