Electron surface waves in a plasma slab with uniform ion density

Abstract

Electron surface waves in a metal bound plasma slab have been detected and analyzed. In this work it is shown that the presence of a matrix sheath between the central quasineutral region and the metal walls allows for the propagation of surface waves analogous to those found in dielectric bound plasmas. Measurements of the dispersion relations and eigenfunctions of asymmetric and symmetric, electrostatic, surface, and body waves are made via particle-in-cell simulation of a plasma slab with sheaths. The plasma slab has finite temperature electrons and fixed ions of uniform density. The sheaths consist of electron free, fixed, uniform ion regions (“matrix sheath”) of thickness ∼λDe. A linearized Vlasov theory is developed for comparison with the simulation. It is shown that the long wavelength approximation (kλDe≪1) is not valid even for long wavelengths in the propagation direction. Collisionless damping of both surface and body waves is measured which compares well with theoretical estimates.