ELECTRON-ATOM COLLISIONS IN A LASER FIELD

The present work is a report on recent progress made in our understand ing of electron-atom collisions in a laser field. To some extent it is a continuation of a previous review covering a somewhat larger subjec t (Can. J. Phys. 63 (1985) 907). We shall discuss the present status o f investigations in this field from the theoretical as well as experim ental point of view but most of the report will be devoted to an analy sis of the various approximation schemes used at present in this field to describe the different aspects of laser-assisted electron-atom int eractions. As the table of contents shows, most of the work done so fa r is treating the atom as a spectator, described by a potential and on ly very little has been achieved over the years to include the atomic structure into consideration since the inclusion of these structure ef fects poses considerable computational problems. Since, for example, m ultiphoton ionization and its inverse process laser-assisted recombina tion may be considered as one half of a scattering process, it is quit e natural that some of the theoretical techniques described here are a lso of interest for the treatment of other multiphoton processes not c onsidered here since there are several other recent reviews available on these topics. (C) 1998 Elsevier Science B.V. All rights reserved.