Numerical simulation of electromagnetic filamentation and hollowing instabilities during collisions of counter-streaming plasmas

We present the results of two dimensional PIC (Particle-in-Cell) simulation s of plasma cloud collisions. We investigate two different types of the pla sma configuration: in the first one the initial configuration is assumed to have the slab form and the second configuration has a form of the cylindri cal. In both cases we found that the counterstreaming motion of the plasmas is unstable with respect to the electromagnetic mode excitation with the d eveloping of the hollow structures in the electron density distribution, th e formation of the electric current filaments and the merging of the filame nts and quasistatic magnetic field generation.