采用水电极介质阻挡放电装置,在氩气和空气的混合气体放电中,对超四边形斑图的形成进行了实验研究.发现随着外加电压的升高,斑图类型经历了四边形斑图、准超点阵斑图、超四边形斑图、条纹斑图或六边形斑图的演化顺序.对这些斑图进行了傅里叶谱分析,得到了空间模式随电压的变化关系.此外,在外加电压升高的过程中,出现了具有不同空间尺度的两种超四边形斑图,它们满足不同的驻波条件.分析了壁电荷在超四边形斑图形成中的作用.实验测量了斑图类型随气隙间距和外加电压变化的相图以及超四边形斑图随气隙间距和气隙气压变化的相图.测量了击穿电压和超四边形斑图的产生电压随空气含量变化关系,发现随着空气含量的增大,击穿电压和超四边形斑图的产生电压都逐渐增大.
The formation of the square superlattiee pattern in discharge in the mixture of argon and air is investigated by using a dielectric barrier discharge device with water electrode. It is found that the bifurcation process of the patterns follows goes through the stages of square pattern, quasisuperlattice pattern, square superlattice pattern and the stripe or hexagonal pattern. Their spatial Fourier spectra are analyzed and the variation of the wave vector as a function of the applied voltage is determined. In addition, two types of square superlattice patterns with different spatial scales are observed with the applied voltage increasing. They all satisfy the standing wave condition. The role of wall charge accumulated in the dielectric layers in the formation of the square superlattice pattern is analyzed. Both the phase diagram on the plot of pattern type against the gas gap width and applied voltage and the phase diagram on the plot of the square superlattice pattern against the gas gap width and the gas pressure are obtained. In addition, the changes of the breakdown voltage and the voltage of the square superlattice pattern as a function of the air concentration are determined. It is found that they increase with the increasing of the air concentration.