A moment model for radio-frequency plasmas

Electron fluid models based on the drift-diffusion approximation usually fail to fully capture the power absorption from to radio-frequency electric fields at low and intermediate pressures, as they are not able to fully describe the kinetic phenomena. In this work, we consider a moment model that solves for first the first five moments of the kinetic transport equation (density, momentum, pressure tensor, heat-flux vector, and contracted fourth moment), which results in 14 scalar variables (14-M), while including the inertial terms. The model self-consistently accounts for the collisional exchanges with other species, including Coulomb, elastic, inelastic (e.g., electronic excitation), and ionization collisions. We compare our 0D moment model to 0D Monte-Carlo collision (MCC) simulations considering radio-frequency fields at different pressures and field magnitudes. In this presentation, we will discuss the effects that are often neglected in fluid models and their origin from a moment point of view.