Pulsed large aperture E-beam sustained CO2 laser discharge optimization

Results of an experimental program are presented to resolve critical discharge loading and confinement issues for high energy pulsed electron-beam sustained CO2 lasers. The investigations focus on kinetically optimizing the energy loading of a helium-free gas mixture 3:1:0.08 (N2:CO2:H2), and investigating and optimizing configurations for controlling discharge confinement while suppressing plasma streamers and associated arc formation. Factors affecting cavity arcing are isolated and treated in a series of systematic tests, and optimization procedures used to achieve kinetically optimized energy loadings are described. Previous arcing limitations are overcome to permit higher E/N's, energy loadings and projected higher specific laser outputs. At the highest E/N's, a sustainer current oscillation is observed and the discharge plasma exhibits a luminous glow transverse to the applied field.