The approach to statistical equilibrium in collisionless wave-particle interactions

The long-time behaviour of the wave-particle interaction is investigated through a Fermi-like model that describes the interaction as the results of a large number of collisions between an ensemble of particles and two infinitely massive barriers with variable amplitude. The results are compared with those of particle in cell (PIC) simulations. The system approaches statistical equilibrium through a phase space filamentation that is analogous to a laminar Gibbs process in a conservative system.