不同时空结构的四边形放电斑图等离子体参量研究

采用发射光谱法，研究了不同时空结构四边形斑图的等离子体参量。实验发现，在低气压区和高气压区，四边形斑图表现出不同的时空结构。利用N₂分子第二正带系的六条谱线强度计算了分子振动温度;利用第一负带系N+₂(391.4 nm)与第二正带系N₂(394.1 nm)谱线强度比，研究了电子能量的变化;利用Ar原子696.54 nm谱线的展宽和频移来反映电子密度;利用Ar原子特征谱线强度比法计算了电子激发温度。结果表明：低气压区四边形斑图的分子振动温度、电子激发温度和电子平均能量均大于高气压区四边形斑图，而电子密度小于高气压区四边形的电子密度。

Investigation of Plasma Parameters of the Square Pattern with Two Kinds of Spatiotemporal Symmetry in Dielectric Barrier Discharge

Two kinds of square patterns with different spatiotemporal symmetry were observed in dielectric barrier discharge, and their plasma parameters were measured by using optical emission spectra. It was found that the spatiotemporal symmetry of the square pattern at lower gas pressure is different from the one at higher gas pressure. Six spectral lines in the emission spectrum of the N₂ second positive band were chosen to estimate the vibrational temperature, and the ratio of I_391.4/I_394.1 was used to represent the average electron energy. The excitation temperature was determined by the ratio of I_763.2/I_772.1. Furthermore, the width and shift of Ar Ⅰ 696.54 nm were used to estimate the electron density. The results show that the vibrational temperature, excitation temperature and electron energy of the square pattern at lower gas pressure are higher than those at higher gas pressure, while the electron density is lower than that at higher gas pressure.