Method of improving the dielectric strength of vacuum insulation

At low field strength insufficient for field emission of electrons, processes arise at defect sites on the surface of high-voltage electrodes that produce prebreakdown currents, initiating microdischarges, and eventually breakdown of the vacuum gap (vacuum arc). These processes may be suppressed by lowering the gas saturation of the electrodes. It is suggested that high-voltage electrodes be made of metallic beads, which are degassed much more rapidly than all-metal electrodes. This aids in improving the dielectric strength of the vacuum gap.