Insulation of High Voltage Across Solid Insulators in Vacuum

Abstract

Surface conductivity and flashover in vacuum were studied using constant potentials up to 350 kV. Since discharges along the solid-vacuum interface appear to originate at or near the junction of the cathode electrode and the solid dielectric, methods of reducing the electric field at this critical region were explored. The more favorable approaches showed higher initial flashover values and could be conditioned to support more than 200 kV across borosilicate glass insulators in an interelectrode gap of 25 mm. The importance of intimate contact at the cathode-to-glass junction was confirmed.