An array of atmospheric pressure plasma jets from a single ionization wave

Abstract

Atmospheric pressure plasmas are being investigated for wound healing, agricultural enhancements, sterilization, and functionalization of materials. An often used configuration is the atmospheric pressure plasma jet (APPJ). Although highly effective, the plasma emanating from the APPJ covers a small area. In order to increase the area treated arrays of APPJs have been developed. The individual jets in such arrays often have inter-jet interactions and may require multiple power supplies. In this paper, we discuss results from a computational investigation of an APPJ geometry which enables multiple jets to be generated from a single ionization wave and has a minimum of jet-to-jet interactions. The configuration consists of a dielectric tube having a row of holes along its length. Helium flows through the dielectric tube and out the holes as a He plume into ambient humid air. The discharge is initiated by a powered annular electrode inside the tube and a grounded ring electrode outside of the tube which overlaps the inner electrode. An ionization wave (IW) propagates along the inside of the tube and over the holes. Depending on the size of the holes, secondary IWs are launched from the holes perpendicularly to the tube into the He plumes, thereby producing a comb of plasma jets. This configuration is based on the work of Robert et al.[1]