Vacuum surface flashover characteristics and secondary electron emission characteristics of epoxy resin and FRP insulator

Yamano, Yasushi*; Takahashi, Masahiro*; Kobayashi, Shinichi*; Hanada, Masaya; Ikeda, Yoshitaka

To improve voltage holding capability of the JT-60 negative ion source toward JT-60SA, the feasibility of the low-outgassing epoxy resin, whose outgassing rate is ten-times lower than the conventional ones, was examined. After sufficient conditioning, voltage holding capability of the low-outgassing epoxy resin was 100 kV, which was limited by the power supply. This value was 1.5 times higher than that of conventional epoxy resin. In addition, an initial applicable voltage was 3 times higher than that of conventional epoxy resins. These results show that the low-out gassing epoxy is feasible as an insulator of JT-60 negative ion source.