低气压直流辉光放电数值模拟与实验研究  

Numerical Simulation and Experimental Study for Low-pressure Direct-current Glow Discharge

作　　者：张百灵[1] 王宇天[1] 李益文[1,2] 樊昊[1] 高岭[1] 段成铎 

机构地区：[1]空军工程大学等离子体动力学重点实验室,西安710038 [2]西北工业大学航天学院燃烧热结构与内流场重点实验室,西安710072

出　　处：《高电压技术》2016年第3期724-730,共7页High Voltage Engineering

基　　金：国家自然科学基金(11372352;51306207)~~

摘　　要：为进一步探究低气压直流辉光放电机理,建立了基于局部平衡假设的2维直流辉光放电模型,研究了正常辉光向异常辉光放电的转变过程及其放电特性,并将异常辉光放电数值模拟结果与实验结果进行对比分析。结果表明,正常辉光放电时,在放电电压小幅增大的情况下,放电区域的扩大使放电电流增大,阴极位降区厚度减小,并出现明显的负辉光区。进一步增大放电电压,放电将覆盖整个阴极表面,可以明显区分出阴极位降区、负辉光区和正柱区,此时放电转变为异常辉光放电;放电电压为400 V时的阴极位降区电场强度高达3 200 V/cm。异常辉光放电、气压不变时,增大放电电压不会改变放电结构,但负辉光区的电子数密度增大使电流增大、放电增强;放电电压为400 V且气压在50-420 Pa之间时,放电电流将随气压的升高而增大。In order to further explore the mechanism of direct-current glow discharge at low pressure, we proposed a two-dimensional DC discharge model based on local equilibrium approximation. Then we investigated the process of transition from normal to abnormal glow and their characteristics, and compared the numerical simulation results of abnormal glow with experiment results. The results show that, in normal glow discharge, when the voltage increases slightly, the current increases as a result of the increase of discharge region, the thickness of cathode fall decreases, and the negative glow becomes manifest; when the voltage further increases, discharge region covers the whole surface of cathode, and can distinguish cathode fall, negative glow, and positive column regions, then the normal glow translates to the abnormal glow. The electrical field in cathode fall is 3 200 V/cm when the voltage is 400 V. When discharge is abnormal glow and gas pressure is constant, the increase of voltage can not change the structure of discharge, the current increases and discharge enhances because of the increase of electron number density in the negative glow; when voltage is 400 V and the air pressure is in the range of 50-420 Pa, the discharge current increases with the gas pressure.

关 键 词：正常辉光 异常辉光 等离子体 气体放电 阴极位降 电子数密度 

分 类 号：O461.21[理学—电子物理学]