常压氩/氮射频容性放电冷等离子体的发射光谱诊断

Diagnostics of Atmospheric-Pressure Radio-Frequency Capacitively Coupled Ar/N_2 Plasma by Optical Emission Spectroscopy

实验中在大气压下在射频(13.56MHz)容性耦合的平板形金属电极的构型中实现了氩/氮射频α模式的辉光放电。首先,采用发射光谱的方法测量了氮分子(C3Πu)谱线随氮气含量的变化;其次,使用玻耳兹曼斜率法估算了OH谱带(A2Σ+→X 2Π)的转动温度,并得到等离子体温度随输入功率的变化规律。最后,选取氮的第二正带(C3Πu→B3Πg)的三组顺序带组对分子的振动温度进行了研究。实验结果表明:随着氮气流量的增加,氮分子谱线强度值先增加后减小,并在氮气流量为80mL.min-1附近达到极大值;气体温度随着输入功率的增加而增加,当输入功率从30W增加到210W时,对应的气体温度从342K增加到523K;随着掺入氮气的流量从30mL.min-1增加到140mL.min-1时,振动温度保持在1 800K值附近基本上不受影响。

An atmospheric-pressure Ar/N2 glow discharge was achieved in α mode stricken between bare metal plate electrodes by radio-frequency power supply at 13.56 MHz.The rotational temperature was determined by using the Boltzmann plot of the OH（A 2Σ＋→X 2Π） radical and the variation tendency of the gas temperature versus the input power was obtained.Furthermore,the measurement of the sequences of vibrational bands of N2 second positive system（C 3Πu→B 3Πg） is made and the vibrational temperature was determined correspondingly.The experiment results showed that the emission peaks of N2（C 3Πu） reached the maximum at the nitrogen flow rate of 80 mL·min-1 with increasing addition of nitrogen,the gas temperature increased from 342 to 523 K when the input power increased from 30 to 210 W,and the vibrational temperature changed slightly when the gas flow rate of nitrogen increased from 30 to 140 mL·min-1.