Modelling of large-scale microwave plasma sources

Theoretical models have been developed for large-scale microwave discharges driven by surface waves which account in a self-consistent way for the main plasma balances, including bulk and surface elementary processes, as well as wave electrodynamics. The systems under consideration are long tubular and large-volume, slot-antenna excited plasma sources. As an example of application, discharges in N-2-Ar mixtures, which are characterized by a complex kinetics, are analysed in some detail. The approach used describes self-consistently the spatial structure of the plasma sources, i.e. the spatial distribution of population densities of excited species, charged particles and ground-state molecules and atoms taking into account the main energy exchange pathways as well as plasma-wall interactions. The model predictions are shown to compare well with experiment in the case of both sources. It is demonstrated that the self-consistent models developed provide deep physical insight into the discharge workings, being also instrumental as a tool for the optimization of these plasma sources in view of specific applications.