无加热器空心阴极的击穿电压特性研究

An Investigation of Breakdown Voltage Characteristics in Heaterless Hollow Cathode

关键词:  无加热器空心阴极  JBP算法  击穿电压  路径转移  起始击穿路径

Key words:  Heaterless hollow cathode  JBP model  Breakdown voltage  Path transition  Critical breakdown path

摘要:

为预估无加热器空心阴极（HHC）的击穿电压，基于汤森放电理论结合对起始击穿路径判定方法，建立一种击穿电压预估的新算法（JBP法）。接着，开展HHC击穿试验以验证该算法的计算精度，计算与试验所得的击穿电压-气体流率曲线（BV-fr）具有较好的吻合度，误差在2.1%～5.6%，并且，揭示BV-fr曲线的“类直线”特性，以证明JBP算法的合理性。在此基础上，对HHC不同关键尺寸下的BV-fr曲线进行数值计算。结果表明，随气体流率升高，HHC的起始击穿路径总会从长路径向短路径转移，而增加间隙中最长路径的长度可以有效实现低流率下的击穿电压降低，本文工况可降低177V。

Abstract:

To predict the gas breakdown voltage of the heaterless hollow cathode （HHC），a new algorithm has been established based on both the Townsend discharge theory and the judgment of the critical breakdown path，namely the JBP model. Moreover，a breakdown test of HHC has been conducted to examine the accuracy of JBP. According to the comparison of test and calculation results，the BV-fr curve solved by the JBP was consistent quantitatively with that measured by the test，and the computational error ranged within 2.1%~5.6%. In addition，the “straight line part” characteristic has been explained by the JBP model，which can prove the reasonability of this model. Based on those above，an analysis of the formation reason of the breakdown voltage-flowrate （BV-fr） in HHC and numerical calculations for several typical cases of HHC with different key geometries have been carried on. From the results，the critical breakdown path would possibly transition from a long path to a short path as the gas flow rate rising，and the breakdown voltage at low flow rates can be reduced with the length of the longest potential breakdown path increasing in the gap. For example，an optimized breakdown voltage can be decreased by 177V in this present study.