Numerical simulation of discharge mode conversion with multiple current pulse (MCP) in atmospheric pressure He/N₂ dielectric barrier discharge

A one-dimensional fluid simulation model of He/N₂ dielectric barrier discharge with parallel plate electrodes was established to study the effects of different parameters (such as gap width, secondary electron emission coefficient γ, and driven frequency) on the characteristics of multiple current pulse (MCP) discharge and the discharge mode conversion. The discharge can be divided into Townsend discharge, transition state, and glow discharge. The results show that with the increase in γ, the number of discharge current pulses increases, making it more difficult to form a glow discharge. When γ is larger, the first discharge approaches the glow discharge mode, but the positive column region is not completely formed, and the subsequent discharge sequence undergoes a transition state to Townsend discharge gradually. Under the condition of larger γ, MCP discharge with a short gap is Townsend discharge. With the increase in the gap width, the transition state will appear in the first discharge, and the subsequent discharge sequence may be converted into Townsend discharge. When the gap width increases further, the discharge can be completely transformed into glow discharge. The pulse number of discharge current decreases with the increase in frequency, and the higher frequency is conducive to the formation of glow discharge.