气体开关击穿机理的初步研究  

Preliminary Research on Breakdown Mechanism of Gas Switch

作　　者：彭建昌[1,2] 王颖[1,2] 王利民[1,2] 李爽[1,2] 王雪峰[1] 林强[1] 谢晋[1] 

机构地区：[1]西北核技术研究所,西安710024 [2]高功率微波技术重点实验室,西安710024

出　　处：《现代应用物理》2014年第2期129-134,共6页Modern Applied Physics

摘　　要：分析了气体开关阴极表面初始电子的产生机制及其影响因素,给出开关电场是决定发射电流密度的关键因素。根据汤逊碰撞理论,讨论了开关电场、气压和温度对汤逊第一电离系数的影响。在温度和气压保持不变时,汤逊第一电离系数随开关电场的增大而增大。实验研究了开关输出脉冲前沿及其主要影响因素,研究结果表明,随着开关气压的增高,击穿电场增大,汤逊第一电离系数减小,输出脉冲前沿也减小;提高开关的击穿电场,是加速气体电离过程、陡化输出脉冲前沿的有效途径;在高电场条件下,碰撞电离已经不是气体电离的主要形式。By analysing the mechanism and influential factors of initial electrons generated on gas switch cathode surface, we point out that the gas switch＇ s electric field strength is a key factor af- fecting the field emission current density. According to the collision ionization theory, the influence of the electric field strength, pressure, and temperature on Townsend＇ s first ionization coefficient has been analyzed. While the pressure and temperature are retained constant, Townsend＇ s first ioni- zation coefficient increases with the increase of the electric field strength. Experimental researches on the gas switch＇ s output pulse front and its main influential factors show that by increasing the pressure and the breakdown electric field strength, Townsend＇ s first ionization coefficient increases, the gas ionization process is accelerated, and the output pulse edge will be reduced, so that increas- ing the breakdown electric field strength is an effective way to steep the forefront of the output pulse. Under the condition of high electric field, collision ionization is not the main ionizing form of gas.

关 键 词：气体开关 初始电子 气体电离 电场 脉冲前沿 

分 类 号：TM501.2[电气工程—电器] TM564.1