Slow electromagnetic solitons in electron-ion plasmas

A set of nonlinear differential equations that describe moving relativistic solitons is investigated analytically and solved numerically. The influenc e of the ion motion on the soliton structure is investigated. It is demonst rated that, depending on the propagation velocity, relativistic solitary wa ves can occur in the form of bright solitons, dark solitons, or collisionle ss electromagnetic shock waves. In the limit of a low propagation velocity, a dark soliton can trap the ions and accelerate them. In the case of a bri ght soliton, the effects of ion dynamics limit the soliton amplitude. The c onstraint on the maximum amplitude is related to either the breaking of ion motion or the intersection of electron trajectories. The soliton breaking provides a new mechanism for ion and electron acceleration in the interacti on of high-intensity laser pulses with plasmas. (C) 2001 MAIK "Nauka/Interp eriodica".