Kinetic effects on relativistic solitons in plasmas

We present theoretical and numerical studies of nonlinear interactions between a short, intense laser-beam and a plasma containing hot electrons. Such plasmas are frequently observed in fast-ignition experiments where electrons are heated by intense laser beams. Due to the combined effects of relativistic electron mass increase and relativistic ponderomotive force of the intense laser fields, there appear localized laser pulses in association with large amplitude localized positive potentials. The latter can trap and accelerate electrons to ultra-relativistic energies. This is demonstrated by means of computer simulations of the time-dependent nonlinear electromagnetic wave equation, supplemented by the Vlasov and Poisson equations.