Interaction of lower hybrid wave with fast ions injected by neutral beam on the JT-60 tokamak

Abstract
The acceleration of beam ions due to their interaction with lower hybrid (LH) waves is investigated. The critical coupling density, above which the LH power is absorbed mostly by ions rather than electrons, is found to depend strongly on the LH frequency but not on the refractive index parallel to the toroidal magnetic field. These dependences are in good agreement with the predictions of a simple, clear theory based on a dispersion relation in the electrostatic cold-plasma approximation.