Stimulated trapped electron acoustic wave scattering, electromagnetic soliton and ion vortices in intense laser interaction with subcritical plasmas

Stimulated trapped electron acoustic wave scattering by a linearly polarized intense laser in a subcritical plasma is studied by particle simulation. The scattering process is a three-wave parametric decay of the laser pump into a critical Stokes electromagnetic sideband wave and the trapped electron acoustic wave. As the ion acoustic wave grows in time, it breaks locally, followed by a large relativistic electromagnetic soliton. A new phenomenon, MeV ion vortex in ion phase space, forms by local electromagnetic and electrostatic fields inside the soliton. It is found that the electron acoustic wave mode is similar to the kinetic electrostatic electron nonlinear waves. (c) 2007 American Institute of Physics.