基于陶瓷-金属焊接的强流二极管绝缘结构设计  

Insulation Structure for a High Current Diode by Ceramic-metal Welding

作　　者：荀涛[1] 张建德[1] 杨汉武[1] 王勇[1] 赵延宋[1] 

机构地区：[1]国防科技大学光电科学与工程学院,长沙410073

出　　处：《高电压技术》2009年第2期355-358,共4页High Voltage Engineering

基　　金：国家高技术计划发展项目资助课题(编号略)~~

摘　　要：应用氧化铝陶瓷作为强流二极管中的绝缘体,实现金属化连接,是器件保真空的基础。为了提高强流二极管陶瓷界面的耐压强度,应用ANSYS有限元程序计算了陶瓷真空界面的电场分布,并根据沿面闪络理论和径向绝缘设计思想,结合具体封接工艺,提出了一种适合小尺寸陶瓷板的套封结构。数值模拟显示,该结构在400kV外加电压下,陶瓷沿面最大场强≤70kV/cm,阴极三结合点场强<30kV/cm;在水介质单线长脉冲加速器上对二极管进行了耐压测试,所设计的绝缘结构能够稳定耐受420kV、200ns脉冲电压,与理论计算比较相符。For one kind of high current diodes composed of a ceramic-metal welding water-vacuum interface, a cover sealing structure was proposed and evaluated. According to vacuum flashover theories, the radial insulator design ideas were gathered and a cone-column anode crust combining shielding methods was adopted. The influence of flexible sealing alloy on the vacuum insulation was also considered and analyzed by FEA methods. Simulation results indicate that by adjusting the anode outline and shielding shape, the electric fields along the insulator are well distributed and the field around the triple junction （TJ） is effectively controlled： with 400 kV applied voltage, the maximum electric field along ceramic surface is less than 70 kV/em and the field around cathode TJ is under 30 kV/em. High voltage test was carried out on a long pulse accelerator based on a water dielectric pulse forming line （PFL）. Experimental results confirm the theoretic design： the vacuum interface of the diode can stably hold on 420 kV and 200 ns pulse voltage.

关 键 词：强流二极管 径向绝缘 闪络 真空封接 陶瓷 结构设计 

分 类 号：TL503[核科学技术—核技术及应用]