Scattering of plane plasma waves from a plasma sphere

Abstract

The scattering of plane longitudinal and transverse plasma waves from a plasma sphere is investigated. The general expressions of scattering cross-sections are given and for the limiting cases well-known hydrodynamics and electromagnetic solutions are obtained. Furthermore, it is shown that by boundary coupling, incident longitudinal or incident transverse plasma waves generate longitudinal and tranverse plasma waves in scattered and transmitted fields. We find that pure acoustic type of radiation is possible only upon the incidence of a longitudinal wave on the plasma sphere. This mode of radiation is the lowest mode (zero mode) of the scattered waves. Light radiated from the incidence of longitudinal waves is not polarized, whereas the incident transverse waves generate polarized light. The problem of light scattering from a plasma sphere is treated, and as a special case, the results of the problem of Mie are derived. Furthermore, in Rayleigh-wave range, agreement with Born approximation solution is established. In this range of wave-lengths the lowest modes have scattering cross-sections proportional to the fourth power of the wave number, and the scattered longitudinal waves are created more efficiently than the scattered transverse waves.