Electrostatic discharges from charged particles approaching a grounded surface

A program based on the boundary element method enabled accurate computation of the electric field in the gap between a conductive sphere of given charge and a grounded plate. The information on field distribution represented the input data of another program which estimated the dielectric strength of that gap in air at atmospheric pressure. In this way, it was possible to determine the critical conditions (charge, gap length) in which a discharge occurs between spherical objects of various sizes and a grounded surface. In all the situations under study, the computed data were in good agreement with the experimental results.