Evolution of electron phase-space holes in a 2D magnetized plasma

The nonlinear stage of the two-stream instability in a 2D magnetized plasma produces electron phase-space tubes, the counterpart of phase-space holes in a 1D plasma. These tubes align primarily perpendicular to the magnetic h eld Bo and have self-consistent bipolar electric fields parallel to Bu. Suc h bipolar electric fields have recently been observed in four different reg ions of the Earth's space plasma environment. Massively parallel 2D kinetic simulations show the dynamics of tube formation, evolution, and breakup, a ccompanied by the generation of electrostatic whistler waves. We focus on t he breakup of the tubes and describe a new numerical study of tube stabilit y.