KINETIC MODELING OF INTENSE, SHORT LASER-PULSES PROPAGATING IN TENUOUS PLASMAS

Fast time averaged equations are derived for the motion of particles a nd the generation of electromagnetic wake fields under the action of t he ponderomotive potential of an ultraintense laser pulse propagating through a tenuous plasma. Based on these averaged equations, a new par ticle code is designed which calculates the particle trajectories on t he plasma period time scale. The regime of total cavitation of the pla sma is investigated. It is found that stable propagation over a long d istance is possible in this regime, and that energetic electrons are p roduced with a simple characteristic dependence of their angle of defl ection on energy. This new code allows for computationally efficient m odeling of pulse propagation over great distances. (C) 1997 American I nstitute of Physics.