压强对介质阻挡放电中八边形结构等离子体温度的影响

利用水电极介质阻挡放电装置，在氩气和空气的混合气体中，首次观察到了由点和线组成的八边形结构。采用发射光谱法，研究了八边形结构中的点和线的等离子体温度随压强的变化关系。利用氮分子第二正带系(C3Π_u→B3Π几_g)的发射谱线，计算了点和线的分子振动温度;通过氮分子离子391.4 nm和氮分子394.1 nm两条发射谱线的相对强度比，研究了点和线的电子平均能量大小变化;利用氩原子763.26 nm(2P₆→1S₅)和772.13 nm(2P₂→1S₃)两条谱线强度比法，得到了点和线的电子激发温度。实验发现：在同一压强条件下，线比点的分子振动温度、电子平均能量以及电子激发温度均高;随着气体压强从40 kPa增大到60 kPa，点和线的分子振动温度、电子平均能量以及电子激发温度均减小。

Influence of Pressure on Plasma Temperature of Octagon Structure in Dielectric Barrier Discharge

Octagon structure consisting of the spots and lines was firstly observed in discharge in argon and air mixture by using a dielectric barrier discharge device with water electrodes. Plasma temperatures of the spots and lines in octagon structure at different gas pressure were studied by using optical emission spectra. The emission spectra of the N2 second positive band(C3Π_u→B3Π_g)were measured, and the molecule vibrational temperatures of the spots and lines were calculated by the emission intensities. Based on the relative intensity of the line at 391.4 nm and the N₂ line at 394.1 nm, the average electron energy of the spots and lines were investigated. The spectral lines of Ar Ⅰ 763.26 nm (2P₆→1S₅) and 772.13 nm (2P₂→1S₃) were chosen to estimate electron excitation temperature of the spots and lines by the relative intensity ratio method. The molecule vibrational temperature, average electron energy, and electron excitation temperature of the lines are higher than those of the spots at the same pressure. The molecule vibrational temperature, average electron energy, and electron excitation temperature of the spots and lines decrease with pressure increasing from 40 to 60 kPa.