Effect of different dopant in machinable ceramic on its surface flashover characteristics in vacuum

As well known, the secondary electron emission 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 were doped into the original glass ceramics to investigate the effects of different process technology on the surface flashover phenomena of the machinable ceramics under pulse voltage in vacuum. We found that after doping the metal oxide, the samples´ surface flashover voltage has changed. Experimental results revealed that after doping metal oxide into the machinable ceramic, the sample´s SEE yield relatively reduced.