Two-Dimensional Numerical Simulation of the DC Glow Discharge in the Normal Mode and with Einstein’s Relation of Electron Diffusivity

This paper presents an investigation of a DC glow discharge at low pressure in the normal mode and with Einstein＇s relation of electron diffusivity. Two-dimensional distributions in Cartesian geometry are presented in the stationary state, including electric potential, electron and ion densities, longitudinal and transverse electrics fields as well as electron temperature. Our results are compared with those obtained in existing literature. The model used in this work is based on the first three moments of Boltzmann＇s equation. They serve as the continuity equation, the momentum transfer and the energy equations. The set of equations for charged particles presented in monatomic argon gas are coupled in a self-consistent way with Poisson＇s equation. A parametric study varying the cathode voltage, gas pressure, and secondary electron emission coefficient predicts many of the well-known features of DC discharges.

低气压直流辉光放电数值模拟与实验研究

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。

亚辉光放电在HL-1装置的应用

本文简述亚辉光放电在HL-1装置上的应用。实验表明,这是一种安全、简便有效的清洗和碳化手段,它可以弥补磁控清洗放电和碳化的不足之处,并为HL-1M装置器壁锻炼提供了先行试验。