Relativistic theory of electron cyclotron resonance heating

Abstract

The formal theory of the interaction of mildly relativistic electrons with a cyclotron resonant applied electromagnetic field described by geometric optics is developed. The electron distribution function is written as the sum of a quasi-static part f0 and a high frequency part f1. A quasi-linear theory is employed to describe these. The resulting transport equation f0 is written to lowest significant order jointly in the reciprocal of the gyration frequency and the bounce frequency. It includes a relativistic collision term and a drag term associated with synchrotron emission. The linearized equations for f1 are solved, and an expression for the high-frequency current is derived.