Nonlinear instability and saturation of linearly stable current-carrying pair plasmas

The nonlinear instability of current-carrying pair plasmas is investigated with a Vlasov-Poisson model for the two particle species. It is shown that linearly stable configurations are unstable against small incoherent perturbations of the particle distribution functions. The instability gives rise to a self-acceleration and growth of phase space holes. After the growth of the phase-space holes, the instability reaches a chaotic saturation where the finite-amplitude holes interact and merge, and after a long time, the system attains a stable equilibrium state with a smaller drift and a larger temperature than the initial one, and where a few stable phase-space holes are present