Slab-geometry surface waves on steep gradients and the origin of related numerical issues in a variety of ICRF codes

In the ion cyclotron range of frequencies, electromagnetic surface waves are physically relevant for wave–filament interactions, parasitic edge losses and sheath–plasma waves. They also important numerically, where non-physical may occur as side effects slab-geometry approximations. We give new, completely general, mathematical techniques to construct dispersion relations between any two media, isotropic or anisotropic, first-order corrections when material interface is steep but continuous. discuss numerical issues (localized non-convergence, undesired power generation) that arise in calculations due presence