Induced plasma nonuniformities and wave vector cascade in the strong wave-plasma interaction.

The interaction of finite amplitude electrostatic waves with an unmagnetized electron-ion plasma is studied by means of a one-dimensional kinetic code that solves the Vlasov equations for the plasma species coupled with the Poisson equation for the self-consistent electric field. An external force acts upon the charged particles, in the form of the sum of several counterpropagating electrostatic waves, characterized by a unique frequency and a broad wave-vector spectrum, which form a standing wave pattern. The interplay between several nonlinear aspects of the interaction, such as the wavebreaking, the particle trapping, the electron heating, the production of ion beams, and the principal role of the wave-induced plasma density nonuniformities as the trigger of the above processes are investigated.