Global Modeling of N_2O Discharges: Rate Coefficients and Comparison with ICP and Glow Discharges Results

摘要

We developed a Global Model for N_2O plasmas valid for applications in various power, gas flow rate, and pressure regimes. Besides energy losses from electron collisions with N_2O, it takes into consideration those due to molecular N_2 and O_2 and to atomic N and O species. Positive atomic N~+ and O~+ and molecular N_2O~+, N_2~+, and O_2~+ have been treated as separate species and also negative O~- ions. The latter confer an electronegative character to the discharge, calling for modified plasma sheath and plasma potential formulas. Electron density and temperature and all species densities have been evaluated, hence the ionization and dissociation percentages of N_2O, N_2, and O_2 molecules and the plasma electronegativity. The model is extended to deal with N_2/O_2 mixtures feedings, notably with air. Rate coefficients and model results are discussed and compared with those from available theoretical and experimental work on ICP and glow discharge devices.