在氩气和空气混合气体介质阻挡放电中,研究了放电丝结构随外加电压及气体压强的变化,并从二维体系相变的角度进行了分析.随着电压的增加,放电丝结构的演变过程为:稀疏的随机放电丝—稠密的随机放电丝—六边形结构—超六边形结构—混沌态,此过程相应于二维体系的气相—液相—简单晶体—超点阵晶体—液相的相变过程.实验还研究了相变过程中超六边形形成中晶格常数及相邻格点间距离的变化、超六边形结构中大点的形成过程以及超六边形结构的Penta-Hepta缺陷.
The evolution of filaments structure with the applied voltage and gas pressure in dielectric barrier discharge in argon/air mixture is studied, which is also analyzed in the aspect of two-dimensional phase transition. With the increase of the applied voltage, the filaments structure undergoes stages of sparse random filamen ts-dense random filaments-hexagon structure-hexagonal superlattice structure-chaos, which can be considered as a phase transition from gas-liquid-simple solid-superlattice solid-liquid. The changes of the lattice constant and the distance between two neighboring lattice points are investigated in the process of formation of the hexagonal superlattice structure in the phase transition. In addition, the formation of the large spots and the Penta-Hepta defects in the hexagonal superlattice structure are also studied.