Electron-atom collisions in a strong laser field

The 'elastic' scattering of fast electrons by atoms is studied in the presence of a laser field which, although strong by laboratory standards, is weak compared with the atomic unit of field strength. The 'dressing' of the target due to the laser field is shown to produce important effects on the scattering at small momentum transfers, in particular when photons are exchanged with the field. As an illustration, detailed calculations are performed for 'elastic' electron-atomic-hydrogen scattering accompanied by the transfer of no photons and one photon. (author)