2.5-DIMENSIONAL NUMERICAL MODELING OF THE FORMATION OF A PLASMA CHANNEL DUE TO ION REDISTRIBUTION DURING THE PROPAGATION OF A FINITE SEQUENCE OF RELATIVISTIC ELECTRON BUNCHES THROUGH HIGH-DENSITY AND LOW-DENSITY PLASMAS

Results of numerical simulations of the excitation of wake fields in h igh- and row-density plasmas are presented. The propagation of relativ istic electron bunches in a plasma is described by a closed set of rel ativistic Vlasov equations for two spatial coordinates and three veloc ity coordinates for each plasma component and the nonlinear Maxwell eq uations for self-consistent electromagnetic fields. Numerical modeling shows that, under ordinary experimental conditions (when the length a nd radius of the bunch are much less than the skin depth), the radius of the bunches propagating in a plasma varies over a wide range. In th is case, the dynamics of both the plasma and the bunches is nonlinear. The radial redistribution of the plasma ions in self-consistent field s leads to the formation of a plasma channel. Incorporating this pheno menon is important for studying the propagation of relativistic electr on bunches in a plasma.