Nonlinear evolution of Buneman instability. II. Ion dynamics

The nonlinear evolution of the one-dimensional Buneman instability after saturation due to electron trapping is studied both by analysis and by computer simulation. A nonlinear dispersion relation proposed previously is shown to describe the nonlinear evolution even after the electron trapping sets in. After electron trapping is completed, amplitude oscillation at a frequency close to ω/sub p/i (ion plasma frequency) appears due to the exchange of energy between the ions and the electric field. The maximum energy acquired by the ions reaches more than 10% of the initial electron drift energy