Formative processes in the electric breakdown of potassium bromide

Abstract

A three stage, cascade image intensifier and a Kerr electro-optical shutter have been used to investigate pre-breakdown light emission from single crystals of KBr. Light emission was first observed about 20 nsec before the voltage across the specimen collapsed. A broad band of light emission containing one or more bright cores propagated from cathode to anode, and through one of these cores disruption of the material occurred. The observations are discussed in terms of current theories of electric breakdown of solids. It is suggested that space-charge enhancement of the cathode field and field emission current leads to breakdown.