Characterization of a periodic instability in filamentary surface wave discharge at atmospheric pressure in argon

Abstract

Abstract This study reports on a periodic instability in a microwave atmospheric pressure surface wave plasma. Time-resolved observation by means of a high-speed camera reveals that the discharge can operate in two different regimes. The discharge operates either in a static mode of a controlled number of filaments propagating alongside the wall of the fused silica tube or in a dynamic mode of one or more straight filaments together with one revolving filament. Microwave power and argon flow rate are interpreted as the scaling parameters that govern the self-organization in the discharge. The operating diagram is formed by alternating stripes of static and dynamic mode with well-defined borders.