Effect of Asymmetric Current-Supporting Electron Velocity Distributions on Second Harmonic Electron Cyclotron Resonance Heating: A Ray-Tracing Treatment for the Compass Tokamak

摘要

A limited asymmetric distortion of the distribution of electron velocities parallel to the magnetic field, sufficient to support the plasma current, is considered. Its effects on second harmonic electron cyclotron absorption of the extraordinary mode propagating away from normal incidence are quantified using a fully three-dimensional ray-tracing code. Significant deviations from the zero current power deposition profiles occur, both in real space and in velocity space. At higher densities, the effects of the extraordinary mode cutoff are softened. These considerations should be taken into account in future studies of temperature and current profile modification using second harmonic electron cyclotron absorption on the COMPASS tokamak.