Understanding CO2 decomposition in microwave plasma by means of optical diagnostics

The growing interest to plasma-based greenhouse gas decomposition requires the knowledge of the different kinetic mechanisms inherent in CO2 discharges and post-discharges. This automatically involves extensive plasma diagnostics research work. Among different types of plasma diagnostics, the ones based on optical spectroscopy are of particular relevance due to their non-intrusiveness. The recent progress in optical diagnostics of plasma-assisted CO2 decomposition process is discussed in this work. A microwave surfaguide discharge operating at 2.45GHz in several CO2-containing mixtures was investigated. Optical emission spectroscopy is used to characterize the discharge area of the reactor in terms of fundamental plasma parameters. At the same time, two-photon absorption laser-induced fluorescence is applied for investigation of oxygen and carbon monoxide concentrations in the post-discharge.