Volume Discharges in CO2-Laser Mixtures at Atmospheric Pressures With High Energy Density

Abstract

Conditions of significant increase energy density of pumping volume discharge in CO2-laser mixtures are determined. There are magnification of electron concentration level at the predionization stage and magnification of autoelectron emission current density from cathodes by using of carbon soot on the electrode working surfaces. The level of initial electron concentration up to 108+109 cm −3was increased by addition in main working mixture CO2:N2:He such components as NO, NO2and I2 in small concentrations. Significant increase of volume discharge current density up to 400-:-600 A -cm−2was provided by field emission. Energy density in volume discharge plasma have the next values: 250÷400 mJ.cm −3without gas additions and without carbon soot on the electrode surfaces; 800÷1200 mJ.cm−3with carbon soot on the electrode surfaces; carbon soot on the electrode surfaces and addition NO, NO2or I2 provide energy densities in gas mixtures CO2:N2 without helium up to 2000 mJ.cm−3,