Strong-field multiphoton ionization of hydrogen. TheS-matrix treatment of the elementary process

摘要: A theoretical model is presented to treat the elementary act of strong-field multiphoton ionization atoms when electron continuum final-state distribution important. It based on theS-matrix formalism and treats electron-radiation interaction in an essentially nonperturbative way. Selected numerical calculations concern hydrogen include differential total cross-sections several channels as a function laser intensity. Good, qualitative agreement with experimental observations found for values field intensity which are not critical respect simplifications adopted constructing model. applies particularly use ideal field. Significant departure from instead implications play role, occurs at channel inversion suppression. concluded that treatment be completely satisfactory needs incorporate more realistic such multimode one.