Magnethohydrodynamic surface and body waves in rectangular and cylindrical geometries.

Abstract

Low frequency magnetohydrodynamic (MHD) waves are studied in both rectangular slab and cylindrical geometry cavities containing low β plasmas. The plasma density distribution is modelled by an inner region of constant density surrounded by an outer region of lower density and a conducting boundary. The wave frequencies and fields are obtained as functions of the density distribution and the wavenumber components k║and k┴, the lowest frequency wave mode is a surface wave in which the wave fields decrease in magnitude with distance from the interface between the two plasma densities. It has the properties of a shear wave when k┴/k║ is either small or large but is compressive when k┴ is approximately equal to k║. The surface wave does not exist when k┴ = 0. Higher frequency modes have the properties of fast magnetosonic waves at least in the inner density region.