Diffusion of metal vapor from electrodes to the vacuum interrupter shield and its dependence on electrode construction

In a high-voltage vacuum interrupter, the insulation of the ceramic envelope and shield decreases significantly due to the deposition during arcing. To increase the voltage rating of a vacuum circuit breaker, the diffusion of metallic particles to the vacuum interrupter shield was investigated. Metallic diffusion of the axial magnetic field electrode construction was extremely small because, due to the effect of the magnetic field, plasma was confined and effectively ionized within it. Electrode erosion of the axial magnetic field electrode during arcing was also extremely small.