Pulsed surface flashover across solid insulators in vacuum

Solid insulators are an inevitable link in high voltage vacuum devices to support and separate the high voltage electrodes. When the high voltage electrodes in vacuum are separated by solid insulators, the breakdown occurs, in general, through the surface of the insulators and subsequently lowers the breakdown strength of the system. This type of surface breakdown, known as surface flashover, has been a limiting factor in high voltage insulator design. The phenomenon of surface flashover has been investigated by many researchers [1-6]. However, the basic mechanism leading to this type of breakdown has not been well understood to date.