General parametric dependence of atmospheric pressure argon plasmas

Abstract

Using a global model for atmospheric pressure plasma, we investigated general dependence of plasma properties on power density and plasma size. We built a global simulation for a pure argon cylindrical plasma and observed changes in plasma properties with the power density and plasma size. The study of the power dependence shows that the density of excited species is in general proportional to the power when the power density is low, whereas the density becomes saturated when the power density becomes high enough. These trends are explained by a generalized form of particle balance equation, implying that the same trends for reactive species density would emerge in various plasma conditions. For the plasma size dependence, the electron density increases and the electron temperature decreases for increasing plasma size. Both become saturated when the plasma size becomes large enough. These trends of electron density and temperature are explained by the relative change of the diffusive loss. Our simulation results give a useful insight into the tendency of plasma properties over a wide range of plasma parameters.