Abstract
We investigate the dynamical approach towards equilibrium during the wave-particle interaction process in plasmas. Particle in Cell (PIC) simulations are compared with a Fermi-like model where particle trapping is described as elastic collisions of particles with two barriers whose amplitude is proportional to the energy of the wave. The system approaches statistical equilibrium through a phase mixing described by a filamentation of the phase space, a dynamical system analogous of the Gibbs process of laminar mixing. The system of trapped particles evolves towards the state of maximum entropy and wave-particle interaction creates correlations in the phase space particle trajectories, making Vlasov equation fail in describing the system dynamics.