  In this paper, we present a model based on a local thermodynamic equilibrium,
weakly ionized plasma-mixture model used for medical and technical applications
in etching processes. We consider a simplified model based on the
Maxwell-Stefan model, which describe multicomponent diffusive fluxes in the gas
mixture. Based on additional conditions to the fluxes, we obtain an irreducible
and quasi-positive diffusion matrix. Such problems results into nonlinear
diffusion equations, which are more delicate to solve as standard diffusion
equations with Fickian's approach. We propose explicit time-discretisation
methods embedded to iterative solvers for the nonlinearities. Such a
combination allows to solve the delicate nonlinear differential equations more
effective. We present some first ternary component gaseous mixtures and discuss
the numerical methods.
