Millimeter wave scattering off a whistler and lower hybrid waves in a tokamak

Abstract

Obliquely propagating whistler and lower hybrid waves through a plasma cause density perturbations. A high-frequency electromagnetic wave sent into such a perturbed region suffers scattering. Theory of electromagnetic wave scattering has been developed in a tokamak where the density profile is taken as parabolic. The wave equation has been solved to evaluate the expression for the amplitude of a scattered wave. For typical parameters of the Princeton Large Torus (PLT) [Bernabei et al., Bull. Am. Phys. Soc. 26, 975 (1981)], the ratio of the power of the scattered to the incident electromagnetic wave comes out to be of the order of 10−4 and 10−5 in cases of scattering off whistler and off lower hybrid waves, respectively, which can be detected; the method can, hence, be used for the diagnostics of the waves.