采用光电倍增管和光谱仪, 研究了介质阻挡放电中点线超四边形发光斑图的时空结构和等离子参数。通过对斑图中放电丝光信号的采集和分析可知: 点线超四边形斑图是由四套不同的子结构相互嵌套而成, 在每半个电压周期内依次为小点四边形、大点连线、大点晕和位于大点中心的小点四边形。其中前三套子结构在电压上升沿放电, 最后一套在电压下降沿放电。利用发射光谱法, 采集了氮分子(N2)第二正带系(C3Πu→B3Πg)发射谱线, 并计算得到了点线超四边形斑图中不同子结构的分子振动温度。结果表明: 小点、大点连线和大点的分子振动温度几乎相同。讨论了介质表面的壁电荷分布对点线超四边形斑图的形成及其时空动力学行为的影响。

The spatio-temporal structures and plasma parameters of the dot-line square superlattice luminous pattern are investigated by using photomultiplier and spectrograph. Optical signals from the discharge filaments show that the dot-line square superlattice pattern is an interleaving of four different transient sub-lattices, three of them occur at the rising edge and one of them at the falling edge in each half voltage-cycle. And the discharge sequence is followed as the small-dot square sub-lattice, the big-dot line sub-lattice, big-dot halo sublattice and the small-dot square sub-lattice located in the center of each big-dot. The emission spectra of the N2 second positive band (C3Πu→B3Πg) are collected and used to calculate the molecular vibration temperatures of the four transient sub-lattices in this pattern. Measurements show that different sub-lattices almost have the same molecular vibration temperature. The influence of the wall charge distribution on the formation process and the spatio-temporal dynamics of the dot-line square superlattice pattern are discussed. It is found that wall charges deposited on the dielectric surface have a great influence on discharge process.