Two-dimensional nonlinear dynamics of the nonpotential Buneman instability

The resonance Buneman instability of an electron beam associated with relative motion of electrons and ions is studied. Such instability is developed if the directed electron velocity essentially exceeds their thermal velocity. Numerical simulation is realized under conditions close to the experimental ones. An infinite waveguide filled with neutral cold plasma, in which electrons move with respect to ions, is considered. Transverse particle motion is considered to be frozen by the strong longitudinal magnetic field. It is shown that in spite of the difference in the current behavior, in all the cases the resonance Buneman instability excites a nonlinear ion acoustic wave with the wavelength equal to that of the most unstable Buneman mode. After instability saturation during nearly ω-1 a triple ion compaction is formed and then smeared