Effect of excitation frequency on characteristics of mixture discharge in fast-axial-flow radio frequency-excited carbon dioxide laser

Abstract

A one-dimensional fluid model has been used to describe the effect of radio frequency (RF) on the characteristics of carbon dioxide (CO₂), nitrogen (N₂) and helium (He) mixture discharge at 120 mbar in fast-axial-flow RF-excited CO₂ laser. A finite difference method was applied to solve the one-dimensional fluid model. The simulation results show that the spatial distributions of electron density and current density rely strongly on the modulating driven frequency. When the excitation frequency changes from 5 to 45 MHz, the plasma discharge is always in \alpha mode. Moreover, as the excitation frequency increasing, the higher densities of \mathrm{C}{\mathrm{O}}_{\mathrm{2}}^{\mathrm{V}\mathrm{001}} and {\mathrm{N}}_{\mathrm{2}}^{*\mathrm{V}\mathrm{i}\mathrm{b}} can be obtained, which is important to get higher excitation efficiency for the upper laser level.

Keywords

plasma / numerical simulation / CO₂/He/N₂ mixture discharges / one-dimensional fluid model

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