直流辉光放电氮原子离子的Monte Carlo模拟研究

Monte Carlo Simulation of Nitrogen Atomic Ions in Direct-current Glow Discharge

采用氮直流辉光放电等离子体中快电子和离子(N+2,N+)混合的蒙特卡罗模型,模拟研究了e-+N2N++N+2e和N+2+N2N++N+N2过程离子N+的产生率轴向分布随放电参数的变化规律及其轰击阴极的能量分布.结果表明,两种离解过程中氮原子离子(N+)的产生率均随气压和电压的增加而增大,随放电气体温度的升高而降低;但N+2-N2离解碰撞主要发生在阴极附近.在电压较高时,阴极处的N+主要由N+2-N2离解过程产生;在电压较低时,N+2-N2离解过程可忽略.

By means of the combination of Monte Carlo model of fast electron and ions (N+2,N+) in a plasma, the axial distribution of the creation rate of the atomic ions for both N+2N2 and e-N2 dissociations under different discharge conditions in nitrogen glow discharge and the distribution of the energy for bombarding the cathode were investigated. It was found that the creation rate of the atomic ions increased with increasing the voltage or the gas pressure, but decreased with increasing gas temperature. Ions N+2 are mainly produced by N+2N2 dissociation in front of the cathode at a higher voltage.