Numerical Study of Propagation and Damping of Lower Hybrid Wave in Tokamak Plasmas

Abstract

Incident lower hybrid waves propagate toward the center of the plasma in a spiral form in the poloidal and the toroidal sections and finally are absorbed by the ion and/or the electron Landau damping within the limited spatial region in accordance with the refractive index parallel to the magnetic field, N_⁄⁄, which is varied considerably along the trajectory, because of the toroidicity and the rotational transform. We propose the scaling law of the wave trajectories on plasma parameters, which shows that the control of N_⁄⁄ or the applied frequency is necessary during the lower hybrid heating. These wave trajectories and damping based on the unmagnetized ion model are compared with those based on the magnetized ion model.