Effect of water vapor on the structure and stability of self-organized patterns in atmospheric-pressure pulsed radio-frequency dielectric barrier discharges

The effect of water vapor on the self-organized pattern characteristics of atmospheric-pressure radio-frequency argon dielectric barrier discharges was experimentally investigated. Under high relative humidity (RH) conditions, no side discharges were generated between the two surface discharges of the patterns. As the RH gradually decreases, side discharges begin to emerge and evolve through three distinct modes: uniform glow discharge, non-uniform glow discharge, and filamentary discharge. These structural variations are primarily attributed to changes in breakdown (or maintenance) voltage induced by varying RH. At lower RH levels, the strongest single pattern exhibited spontaneous motion, which in turn triggered the collective motion of patterns. The self-organized pattern motion is explained as the shift of re-ignition position induced by electric interaction between asymmetrical side discharge filaments and the central filament.