A PONDEROMOTIVE FORCE PROPORTIONAL TO E-4 ACTING ON A CHARGED-PARTICLE TRAVERSING A NONUNIFORM ELECTROMAGNETIC-WAVE

Charged particles traversing a spatially nonuniform high-frequency fie ld are investigated with the use of numerical methods. It is shown tha t a particle traversing a linearly polarized nonuniform wave is subjec t to the influence of an averaged force proportional to E-4. The direc tion of this force is opposite of the direction of wave propagation wh en a particle moves toward the region of a strong field and coincides with the direction of wave propagation when a particle leaves the regi on of a strong field. Expressions that describe this force are derived in the approximation where the nonlinearity parameter is small.