Ponderomotive nongradient force acting on a relativistic particle crossingan inhomogeneous electromagnetic wave

The ponderomotive force acting on a relativistic charged particle crossing an inhomogeneous electromagnetic wave is investigated numerically and analy tically. The initial velocity of the particle is perpendicular to the elect ric field vector of the wave and to the direction of its propagation. The w ave has zero gradient in the direction of propagation and is inhomogeneous in both transverse directions. It is shown that the ponderomotive force act ing on the particle is parallel to the wave vector. The magnitude of the fo rce is determined not by the extent of wave inhomogeneity in the direction of the translational motion of particle, but also by its inhomogeneity in t he transverse direction. It is found that the trajectory of a particle is d etermined by the action of ponderomotive forces as well as by its drift in a nonuniform field. (C) 2001 MAIK "Nauka/Interperiodica".