Effects of Ion Collisions on Ion Acceleration by Beating Electrostatic Waves

A numerical model of the nonlinear interaction between beating electrostatic waves and magnetized ions, including collisions, is presented. Previous studies of the beating electrostatic waves (BEW) interacting with a single ion showed the ability of this mechanism to accelerate ions from arbitrarily low initial velocities, and have revealed the fundamental conditions for this interaction to occur. The present study extends the analysis to a large number of ions and includes ion-ion collisions. The numerical investigation combines a dynamical description for the ion-wave interaction and a Monte Carlo simulation of the collisions. Despite the thermalization role of collisions BEW acceleration was found to yield larger heating rate and higher particle energies than the better known interaction with the single electrostatic wave (SEW).