Quasilinear saturation effects on electron cyclotron wave damping of the ordinary mode in tokamak plasmas

Abstract

The quasilinear theory of electron cyclotron wave absorption for the ordinary mode propagating normal to the tokamak magnetic field is investigated. A two-dimensional initial value code has been developed to investigate the distortion of the electron momentum distribution from an initial Maxwellian. It is shown that for powers of interest for electron heating in future tokamaks, Coulomb electron collisions are not sufficient to avoid quasilinear flattening of the electron distribution; therefore, there is a reduction in the damping rate as compared to the linear case.