Phase space flights in non linear Landau camping

The self‐consistent electric field, evaluated by solving numerically the Vlasov‐Poisson system of equations, is used to study the equations of motion of a great number of test particles, in the wave particle resonant region. The analysis of the particle trajectories show that when the initial amplitude of the electric field is above a critical value, the dynamics become chaotic at the border of the resonant region and particles near the separatrix perform flights in the phase space. An accurate statistical analysis of the spatial and temporal duration of these flights, shows that they are not long enough to allow dissipation to go on, but their characteristic length determines the undamped, oscillating long time behavior of solutions.