Planar Helium Plasma Jet: Plasma "Bullets" Formation, 2D "Bullets" Concept and Imaging

Abstract

Applications of dielectric barrier discharge (DBD)-based atmospheric pressure plasma jets are often limited by the relatively small area of treatment due to their one-dimensional (ID) configuration. This letter describes the first results demonstrating generation of two-dimensional (2D) plasma "bullets" and 2D plasma jets that permit rapid treatment of large targets. Imaging of pulsed DBD in helium (He) and ionization wave propagation along the dielectric surface shows that DBD evolution starts with formation of transient anode glow; only then does the development of cathode-directed streamers continue. The anode glow can propagate as an ionization wave along the dielectric surface outside of the discharge gap. We show that plasma "bullet" propagation is not limited to 1D geometry (i.e., tubes) and that it can be organized in a planar plasma jet form or other 2D (or even 3D) shapes.