Calculation of electron-impace excitation and ionization of atoms

Over the last few years it has been the author's goal to develop a open-quotes completeclose quotes electron-atom scattering theory. For a given projectile energy such a theory would be able to correctly predict the major scattering processes. These include elastic, excitation, and ionization cross sections. The convergent close-coupling (CCC) approach is a candidate for such a theory. Hamiltonians in an orthogonal Laguerre basis. The usage of this basis ensures that open-quotes completenessclose quotes is approached as N is increased. The CCC method may be thought of as a more systematic implementation of pseudostate methods. Whereas the success of the close-coupling approach to the calculation of excitation cross sections has been demonstrated for many decades it has rarely been applied to the calculation of ionization processes. By demonstrating the ability to obtain accurate ionization cross sections simultaneously with excitation processes the CCC method appears to have fulfilled these goals. In the talk a general outline of the CCC method will be given and its recent applications to the measurements of electron-impact ionization and excitation of the ground state of helium discussed