【摘要】 在长脉冲强流无箔二极管实验过程中观察到绝缘子沿面闪络现象。分析实验现象认为是屏蔽环与绝缘子距离过近造成了屏蔽环边缘高场强,从而产生场致发射电子。电子在强电磁场作用下撞击绝缘子表面引起了二次电子雪崩从而导致真空表面闪络。运用静电场模拟和粒子束模拟,改进屏蔽环结构。改进后的二极管工作电压500 kV,电流12 kA,在1 T引导磁场下稳定运行,没有再发生真空表面闪络。更多还原

【Abstract】 During the experimental study of a long-pulse intense-current foilless diode,surface flashover along its insulator was observed.The analysis of the phenomenon shows that,too short distance between the shield ring and insulator resulted in an intense electric field at the edge of the shield ring,which leaded to the emission of electrons;with effect of intense electromagnetic field,the electrons came into collision with the surface of the insulator,causing secondary electron emission avalanche,and then resulted in vacuum surface flashover.The structure of the shield ring was improved by use of electrostatic field simulation and particle simulation.The improved diode,whose voltage and current are respectively 600 kV and 10 kA,works steadily with guiding magnetic field of 1 T.Vacuum surface flashover does not take place again.更多还原