Free-free transitions in a bichromatic field of frequencies $\omega $ and $2\omega$ at moderate field intensities

Abstract

Free-free transitions in laser-assisted electron-hydrogen scattering in a bichromatic field of frequencies $\omega $ and $2\omega $ are studied at moderate intensities for fast projectiles. A hybrid approach is used, in which the field-projectile interaction is described exactly but the field-target one is described by second order perturbation theory; the projectile-target interaction is treated in the first Born approximation. The adopted description of the target enables a consistent study of the leading process to each of the considered sidebands. Numerical results are presented for the angular distributions in a geometry and at frequencies for which the target dressing is important. The influence of the relative phase between the fields is investigated, too.