Theory of electron cyclotron resonance heating of tokamak plasmas

A theoretical study of tokamak plasma heating by the 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 of parametric instability are examined; it is tentatively concluded that parametric instabilities and wave scattering should not be important in typical situations of interest