MODELING OF PLASMA-CHEMICAL REACTIONS IN GAS-MIXTURE OF CO2-LASERS .1. GAS DECOMPOSITION IN PURE CO2 GLOW-DISCHARGE

The chemistry of a pure CO2 glow discharge is modelled as a first step in description of CO2 lasers plasma-chemical reactions. The equilibrium conversion of CO2 into CO strongly depends on E/N ratio. It grows from few percent for E/N =2 x 10(-16) V cm2 to more then 70% for E/N approximately 9 x 10(-16) V cm2. The X(e) values are only slightly influenced by the change of electron density and temperature. The role of ions and of the CO(a3PI) excited electronic state in recombination of CO as well as of heterogeneous recombination is studied. The time required to reach the steady-state concentrations of chemical species in the system varies from few seconds for high E/N values up to hours in the other end of investigated region; it increases with the fall of discharge current and with the fall of E/N. Satisfactory agreement with experimental data is achieved.