Optimization design of axial dielectric of DC high-voltage accelerating tube

Axial insulation structure was optimized to reduce potential gradient in DC high-voltage accelerating tubes of 500 mA. At first, both principle of surface flashover and axial insulation structure of accelerating tubes were analyzed. Then, it was found that electric field aberration at the junction of triple junction causes high electric field intensity through numerical simulation in terms of theory of SEEA. Optimal structure is ascertained by analyzing four types of insulation structure respectively and it has such features as angle of +45° between the insulator surface and the cathode, a metal electrode ring embedded evenly in flutes at both ends of insulator and the insulator embedded evenly in the anode.