Difference frequency harmonic ion heating using Whistler modes

Abstract

The heating of ions in a magnetized plasma by the second-order electric fields generated through the nonlinear mixing of two Whistler modes is examined. The kinetic equations describing the mixing and heating process are solved using the method of orbit integrations. Two techniques are available for optimizing the energy absorbed by the ions. One is to allow the mixed wave to approach a natural mode in the plasma, resulting in a field resonance. A second method is to have the ions absorb energy through cyclotron damping. The latter technique and the combination of the two optimizing schemes will be investigated. The resulting sensitivities to fluctuations in frequency, density, static magnetic field, and the direction of propagation of the source waves will be given.