氮异常辉光放电中离子成分及能量分子束质谱诊断

Molecular beam mass spectrometry diagnosis on ion species and their energy distribution in N_2 abnormal glow discharges

利用国内首台三级差分抽空的分子束质谱装置 ,对短间隙氮异常辉光放电阴极鞘层区正离子组分及能量分布进行了诊断研究 .在所研究的实验条件下 (压力 13 3～ 2 79Pa,放电电流 2～ 7m A) ,离子流中主要离子成分是 N+、N+ 2 ,且 N+比 N+ 2 的浓度大 5倍左右 .鞘层区的 N+、N+ 2的能量分布均有一极大值 ,该极值在所研究实验条件下随气压增高而减小 ,随放电电压增大而增大 .

Ion species and their energy in the cathode sheath of N 2 abnormal glow discharges with short electrode interval were determined by molecular beam mass spectrometry (MBMS). Under the experimental conditions (gas pressure between 133 Pa and 279 Pa and discharge electric current between 2 mA and 7 mA), it is found that the main ion species are N + and N + 2, and the concentration of N + is about 5 times higher than that of N + 2 in the total ion flux. The energy distribution of N + and N + 2 in the cathode sheath has a maximum value respectively. The maximum values increase with the increasing discharge electric voltage, but decrease with the increasing gas pressure. The main elementary physico chemical processes in the N 2 plasma are discussed.