Effect of different dopant in machinable ceramic on its secondary electron emission and surface flashover characteristics in vacuum

Secondary electron emission (SEE) yield is one important factor for the flashover phenomena of solid materials under high electric field in vacuum. On the basis of the novel low melting temperature machinable glass ceramics for vacuum insulation system, which has excellent machinable performance and good electrical properties, different low SEE yield metal oxides including Cu₂O and Cr₂O₃ are doped into the original glass ceramics while keeping its machinable performance, to investigate the effects of different process technology on the surface flashover phenomena of the machinable ceramics under pulse voltage in vacuum. The experimental results indicate that after the metal oxide doped into the original material the SEE yield of the sample reduced. By investigating the different samples' flashover voltage it can be seen that with the sample's SEE yield reducing the sample's vacuum flashover voltage increasing.