Kinetic modeling of ar -02 thermal plasma incuding metastable and resonant states of atoms and molecules

Summary form only given. Thermal plasmas have been drawn considerable attention to the researchers and most recent research activities are thermal plasma chemical vapor deposition, plasma coating and synthesis of nanostructured materials. In such applications of thermal plasmas, the understanding of chemical reaction kinetics, production rate and loss rate of different species in the plasma is crucial. A lot of works have been carried out with O₂ plasma, at very low pressure and temperature. In this work, it is aimed to model the Ar-O₂ plasma at thermal state including several metastable and resonant states of argon and oxygen atoms and molecules. With thermal equilibrium assumption (Th=Te), this work investigates the chemical non-equilibrium effects. Ten chemical species of argon and oxygen and sixteen chemical reactions have been considered. The rate coefficients of the forward reactions have been taken from literature. The equilibrium constants, backward reaction rates and partition functions, which account translational, rotational and vibrational excitations, have been calculated. The production and loss rate of species have been calculated from the rate coefficients and number density of species. The equilibrium number density often species has been calculated solving ten simultaneous linear equations by Newton-Raphson iteration method. It is found that the production rate of metastable oxygen atom is very high at low temperature and it decreases with temperature, and that of metastable oxygen molecules rather increases with temperature and become saturated at around 5000 K