Surface cyclotron waves on the plasma-metal boundary

This article considers extraordinary surface cyclotron waves (ESCW) properties on the plasma-metal boundary when applied constant magnetic field is parallel to the boundary. A great number of the experimental data testifies that the surface wave damping and its resonance absorption causes of the plasma heating near the wall of a thermonuclear reactor. The study of the ESCW dispersion and damping may be useful in order to eliminate this heating, because one can choose corresponding conditions for the ESCW suppression. On the other hand ESCW are suitable for various radiophysical applications, because plasma-metal structures are widely spread in plasma and semiconductor radiotechnical apparatuses. The initial equation's system consists of the kinetic equation and Maxwell equations has been solved by the fourier method. The diffuse model of the plasma particles reflection on the metal wall was applied. It was shown that the dispersion equation solutions exist only for the even harmonics of the electron or ion cyclotron frequency. The ESCW propagate only in one direction, which is determined by the Larmor rotation of electrons and ions correspondingly near the plasma-metal boundary. These waves are characterized by the straight dispersion relation and small damping coefficient values. The ESCW's frequencies are greater than correspondent harmonic of the cyclotron frequency. The frequency shifts are proportional to (κ ρ)s, where κ-wave number, ρ-Larmor radius, s-cyclotron harmonic number. The ESCW's dispersion has no dependence upon the waveguide thickness. So ESCW's excitation may be used in such devices as plasma generator. The fact of one-directional ESCW's propagation is very useful for various technological applications for example in nonreciprocal devices