Analytical study of high flow CO electric discharge laser systems

A self-consistent model for high flow CO-N2-He electric discharge laser systems with coincident optical and flow axes is presented. The model employs the multifluid conservation equations, an integral form of the threshold conditions for the lasing transitions, and the electron Boltzmann equation to describe the laser system. The resulting integro-differential system of equations is solved by an iterative numerical technique. The effects of composition, inlet temperature and pressure, total mass flow rate, mirror reflectivity, and input power on the maximum average small signal gain coefficients, the intensities of the lasing transitions, and the efficiency were examined. The results indicate that for a given input power, mirror reflectivity, and N2 fraction, the efficiency is increased by reducing the inlet temperature, increasing the flow velocity, and/or increasing the CO fraction. Transitions on the lower vibrational bands can be obtained at the expense of lower efficiencies by reducing the fraction of CO.