Diffraction by a perfectly conducting semi-infinite screen in an anisotropic plasma

Abstract

The scattering of a plane electromagnetic wave by a perfectly conducting semi-infinite screen embedded in a homogeneous plasma is investigated. A uniform magnetic field is assumed to be impressed externally in a direction parallel to the edge of the half plane. The plasma is idealized to be a dielectric characterized by a tensor dielectric constant. The direction of the incident wave is assumed to be in a plane perpendicular to that of the screen. This vector problem is separable into two equivalent scalar problems for which either the electric or the magnetic vector is parallel to the edge of the half plane. It is found that for the case of the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</tex> mode, the magnetic vector parallel to the edge of the half plane satisfies a simple wave equation and a new type of impedance boundary condition on the screen. This problem is formulated in terms of an integral equation which specifies the current induced on the screen. The integral equation is of the Wiener-Hopf type and is solved by the usual function-theoretic methods. For a given orientation of the external magnetic field, a surface wave is found to exist along the screen but on one side only. The characteristics of this surface wave are determined.