Simulation study of two-ion hybrid resonance heating

A one-dimensional low-noise, low-frequency electromagnetic particle simulation code that is appropriate for investigation of ion-cyclotron resonance heating (ICRH) is developed. Retaining the hyperbolicity of the electromagnetic waves and exploiting nearly one-dimensional characteristics (perpendicular to the external magnetic field) of the ICRH, the guiding center electron approximation for the transverse electronic current calculation is used. Mode conversion of the incoming magnetosonic wave into the electrostatic ion–ion hybrid mode is observed accompanied by strong ion heating. The dependence of this heating on the different plasma parameters is examined through a series of simulations, focusing mainly on wave incidence from the high field side. Because k∥=0 in the runs, the conventional Landau damping cannot explain the ion heating. Nonlinear mechanisms for energy transfer are discussed. The numerical results demonstrate the importance of the nonlinear wave–particle interaction for energy absorption during radio-frequency heating in the ion-cyclotron regime.