Scattering and guided waves at an interface between air and the compressible plasma

Propagation of waves in a compressible, isotropic, collisionless electron plasma is studied. Optical and acoustic modes of propagation are examined in detail. Scattering and guiding properties of a plane interface between free space and plasma are investigated. It is found that electromagnetic energy in theory can be completely converted into plasma waves. A surface wave is found whose properties are affected slightly by the compressibility for
(\omega_{p}/\omega) > \sqrt{2}
. In contrast to the case of purely dielectric plasma, this surface wave has no high-frequency cutoff. Formal expressions for electromagnetic and acoustic fields excited by a magnetic line source in free space, parallel to the interface, are obtained.