Plasma diagnostics of glow discharges in mixtures of CO$_{2}$ with noble gases

Abstract

This study presents the plasma diagnostics of a glow discharge produced in two different mixtures, CO$_{2}$/He and CO$_{2} $/Ar, at a constant pressure of 1.5 Torr. The experiment was conducted to determine the carbon dioxide decomposition in the plasma by using the optical emission spectroscopy $\left(OES\right)$ method through identifying lines and emission bands in the spectra. In addition, an electrical characterization of the mixture plasma was made by the determination of ion density $(n_{i})$ and the electronic temperature $(T_{e})$, estimated through a double Langmuir probe. The electronic temperature for the mixture plasma was in the range of 2.07-5.37 eV, and the ion density between $2.15\times 10^{9}$ and $18.70\times 10^{9}$ particles/cm$^{3}$. The principal bands and lines identified in the OES correspond to CO$_{2}^{+}$, CO$_{2}$, CO$^{+}$, CO, O*, O$_{2}$, O$_{2}^{+}$, C$_{2}$, He* and Ar*.