N_2/H_2辉光放电等离子体电子碰撞电离的Monte Carlo模拟

Monte Carlo Simulation of the Electron Impact Ionization in N_2/H_2 Glow Discharge Plasma

采用N2/H2直流辉光放电等离子体综合的Monte Carlo模型,通过计算N2/H2混合气体直流辉光放电等离子体电子碰撞电离及离解电离率,电子密度及电子能量分布函数,研究了H2的浓度对氮辉光放电等离子体电子碰撞电离过程的影响.研究结果表明：随着H2浓度的升高,电子的电离及离解电离碰撞率减少;但在一定的放电条件下,加入少量的H2,可以提高电子碰撞电离及离解电离率,即选取合适的放电参数,加入少量的氢,可以提高放电空间的电子及离子的密度.模型考虑了12种和电子相关的反应,在氮气中加氢的比例为0-30%.这些影响能通过放电中发生的碰撞过程及鞘层厚度的改变得到解释.研究结果为认识N2/H2混合气体辉光放电等离子体过程机理提供参考依据.

The effect of adding hydrogen to a nitrogen de glow discharge on electron impact ionization is investigated by using Monte Carlo code. The e^- -Nz ionization and dissociation ionization rates, the electron density and the energy distributions of electron in N2/H2 glow discharge plasma are calculated. It is shown that when increasing percentage of H2, The e^- -N2 ionization and dissociation ionization rates are decreased, and that when adding small amounts of Hz into nitrogen gas, e^--N2 ionization and dissociation ionization rates can be enhanced under a certain discharge condition, which will be beneficial to increase the density of electron and ion in discharge space. The 12 reaction processes relating to electron are considered in the model. The hydrogen concentration is varied between 0 % and 30 %. These effects can be explained by the collision processes taking place in the discharge and the change of the length of the cathode dark space.