Theory of electron cyclotron resonance heating of tokamak plasmas

Abstract

A theoretical study of tokamak plasma heating by electron cyclotron resonance is presented. The density limitations imposed by accessibility are first reviewed. Then, the predictions of linear theory (including relativistic effects on the wave absorption) are examined via solutions of the ray equations in a toroidal tokamak equilibrium. These solutions indicate quite favorable characteristics for large tokamaks. Finally, the possibilities of scattering of the incident heating wave by existing drift-wave-type fluctuations and excitation of parametric instability are examined; it is tentatively concluded that parametric instabilities should not be important in typical situations of interest.