Effect of ozonized water treatment on electrical breakdown of oxygen-free copper electrodes of a vacuum gap

An ozonized water treatment technique was applied to surface treatment of oxygen-free copper electrodes. Breakdown characteristics of the electrodes were measured in a vacuum by applying impulse voltages. Results showed that the breakdown field at the first voltage application was not improved, but the conditioning effect of the gap by repetitive breakdowns was significant. The value of breakdown field after conditioning was around 250 MV/m (for a 0.3-mm gap length). Breakdown fields were lowered to values similar to those of the first voltage application, after the conditioned electrodes were exposed to air for two to three weeks. Reconditioning, however, was achieved rapidly