Dielectric Charging-The Effects of Straggling and Soft X-Ray Irradiation

In this paper, we examine the charge distribution and electric field within a dielectric after it has been charged to saturation by an external kilovolt electron source and then irradiated by soft X-rays. We wish to know whether conditions exist for which soft X-ray irradiation can enhance the electric field in a precharged dielectric and thereby greatly enhance the likelihood of a discharge event. Van Lint et al. reported on discharge events observed on the Skynet satellite qualification model, one of which coincided with soft X-ray irradiation on the precharged satellite exterior. Mandell et al. have suggested a possible mechanism for such events involving surface flashover. We investigate a different mechanism which depends critically on the internal charge distribution and much less so on surface potential.