Discharges in very-short air gaps in plane-parallel electrodes and under AC voltage

This paper presents a study of the conditions leading to discharges under AC voltage. Starting from a simple test configuration, Maxwell´s equation (∇·D=ρ) has been integrated numerically, using the laws of ionization for collision and taking into account that Townsend´s coefficient α, generally, is a local function of the electric field between a two set of electrodes. The values of inception voltages measured at the terminals of a cell which was the site of the discharges, have been utilized in integrating Maxwell´s equation. In this way the electric field configuration between the electrodes immediately before the discharge has been obtained. That allowed us to make some comments on the working conditions, nature of discharges, effects of space charge on mutual interferences, and discharge behavior under AC voltage