Development and Characterization of a Microwave Atmospheric Pressure Plasma Jet

Abstract

Over the past decade, atmospheric pressure discharges in the microwave frequency range have gained significant attention due to their promising applications in material processing, CO2 dissociation, waste management, hydrogen production, water treatment, and more. This study presents the development and characterization of a waveguide-based microwave atmospheric pressure plasma jet (MW-APPJs), focusing on its design, diagnostics, and operational parameters. The setup incorporates a microwave power source, microwave waveguide networks, including the applicator section, and diagnostic tools for measuring plasma properties. Optical emission spectroscopy (OES) is employed to analyze the reactive species and determine plasma parameters which include electron excitation temperature (Texc) and electron number density (ne). The characterization highlights the influence of spatial and temporal gradients, gas flow rates, and power input on plasma behaviour. From OES, the Texc and ne variations were against the power increment. The thermocouple variations are also plotted with power.