大气压空气脉冲流光放电等离子体发射光谱分析

在大气压条件下采用尖-尖电极放电系统得到了稳定的放电等离子体, 并应用发射光谱方法对放电等离子体进行了实验研究。等离子体发射光谱呈现连续谱背景迭加分立谱的形式。连续谱背景来源于放电等离子体内轫致辐射和复合辐射过程; 分立谱归属为N2 C3∏u →B3∏g , N+, N, O的荧光辐射。N+荧光辐射对应的上能级电子组态为2s22p(2P0)3p和2s22p(2P0)3d, 能级高度介于20 eV和23.6 eV之间。实验还结合时间分辨光谱技术, 对放电等离子体中N2(336.8 nm)、N+(500.5 nm)、N+(399.7 nm)荧光信号进行时间分辨测量。结果表明, N2(336.8 nm)荧光首先出现, N+(500.5 nm、399.7 nm)荧光同时产生, 且滞后N2(336.8 nm)荧光约25 ns。根据时间分辨测量结果和相关参考文献, 文章对放电等离子体中N+的生成通道进行了分析。

Emission Spectrum Analysis for Air Plasma by Pulsed Streamer Discharge in Atmospheric Pressure

The paper presented an experimental study on air plasma, which was produced in atmospheric pressure discharge system with two needle electrodes, by using emission spectrum method. The emission spectrum consisted of continuous spectrum background and discrete spectrum above the background. The continuous spectrum resulted from bremsstrahlung and recombination emission in the plasma. The discrete spectrum were assigned to fluorescence emission of N2 C3∏u →B3∏g ,N+,N,O. The upper electron configurations corresponding to N+ fluorescence were 2s22p(2P0)3p and 2s22p(2P0)3d, respectively and their energy levels located between 20 eV and 23.6 eV. Time resolved spectroscopy of N2(336.8 nm), N+(500.5 nm), N+(399.7 nm) fluorescence signals were also acquired. The results show that N2(336.8 nm) fluorescence appeared firstly, then N+(500.5 nm,399.7 nm) fluorescence showed up at the same time with about 25 ns delay. Based on time resolved measurement and related references, the paper analyzed N+ production channels.