An Investigation of the Effect of Gas Additives on the Electron Temperature and Density in a Co2 Laser Discharge

The radial variation of electron temperature and density with partial gas pressures in a CO2–N2–He laser discharge is measured using double-probe and microwave resonance techniques. In a 22-mm-diam discharge tube the optimum partial gas pressures for maximum laser power correspond to an electron temperature of 3 eV and a density of 3 × 109 cm3. The radial electron density profile is compatible with measured gain profiles. The results indicate that the role of He in the excitation mechanism is not due to a reduction in electron temperature.