On the beat interaction of particles with large amplitude spectrum in the description of mixing systems

The effect of stochastic instability of particle motion on nonlinear Landau damping was investigated on a simple model of particles with a discrete spectrum. It was shown that as far as the trajectory of particles was stochastically unstable (at beat resonances under consideration), diffusion of particles took place. The influence of this effect on the nonlinear Landau mechanism commonly assumed is discussed; the possibility of heating in this regime in a beam-plasma experiment is dealt with briefly. (author)