Research on Quasi Honeycomb Superlattice Pattern in Dielectric Barrier Discharge

Patterns formed in dielectric barrier discharge is a typical nonlinear selforganization phenomenon. Research on patterns helps elucidate the formation and evolution mechanisms of spatiotemporal structures in nonequilibrium systems, while also holding potential application value in fields such as material processing and plasma chemical engineering. A honeycomb superlattice pattern with an alternately-stretched honeycomb frame is observed in dielectric barrier discharge with a rectangular modulated gas gap for the first time and is studied both experimentally and theoretically. As the applied voltage increases, the pattern evolves from a hexagonal superlattice pattern with D_6h symmetry to a quasi honeycomb superlattice pattern with D_2h symmetry. Experimentally, the spatiotemporal structures of these two patterns are measured using an ICCD and PMTs. It is found that the hexagonal sublattice in the honeycomb superlattice pattern is divided into two sublattices, including a large stripe sublattice and a small stripe lattice. Additionally, the honeycomb frame sublattice is alternatelystretched. Discharges occur during both the rising and falling edges of the applied voltage. Through estimation of the wall charge quantities of the two types of honeycomb frames and analysis of the influence of boundaries on pattern formation, it is found that the quasi honeycomb superlattice pattern emerges as a self-organized structure under the influence of gas gap symmetry. Theoretically, the Poisson equation is numerically solved using COMSOL Multiphysics to simulate the electric field of the alternatelystretched honeycomb frame before and after discharge during the rising phase of the applied voltage. The result well explains the experimental phenomenon and provides the formation mechanism of the alternatelystretched honeycomb frame.