Propagation of electromagnetic waves in a plasma with a sheared magnetic field

Abstract

The propagation of an extraordinary wave in a toroidal plasma is investigated taking into account small shear. It is shown that an ordinary component can be generated at the upper hybrid frequency. The amplitude of the ordinary wave is proportional to the spatial derivative of θ = Bθ/B0, where B0 is the main magnetic field and Bθ the poloidal component. The result is of a form suggesting a diagnostic scheme for measuring the local value of dθ/dr. A numerical application is given for the case of a T-3 Tokamak.