Corona and micro‐gap discharge at a wire particle in precessional motion under a DC electric field

Abstract

SUMMARYA free wire particle located in an electric field between parallel plate electrodes manifests several motions: standing, precession on the electrode, crossing, and breakdown via the particle. During stable standing or precessional motion, the corona discharge inevitably occurs. To clarify the influence of discharge phenomenon on the behavior of the wire particle, the corona discharge characteristic of the particle in the precession was investigated experimentally in a DC electric field formed by parallel plate electrodes with a positive voltage applied to the upper electrode. The waveforms of the corona discharge current flowing through a 6-mm wire particle were measured under two conditions: when a free wire was in precession on the lower electrode and when a wire was fixed between the electrodes vertically with a spacing of less than 1 mm between the lower electrode and the bottom of the particle. From a comparison of the waveform of corona discharge occurring at the particle in precession with that of the fixed particle, it was found that both micro-gap discharge and negative corona occurred simultaneously only when the particle was in precession with a relatively small elevation angle. The particle was lifted up when the magnitude of the corona discharge current was decreased below about 15 µA.