Tests of continuum distorted waves

Continuum distorted waves have proved useful for the computation of one-electron ion-atom collision processes. Despite this success, approximations based on these functions have not proved reliable for ionization processes involving electron collisions. Recently, it has been noted that if initial states that have the same form as the CDW final state are used in a balanced approach, improved agreement with experiment for (e,3e)(e,3e) processes is found. We have investigated the high energy limit of other double ionization processes, namely (γγ, γ′2eγ′2e) and (γ,2e)γ,2e), and find that such agreement does not extend to the high energy limit. When the CDW initial state is improved, the high energy limit improves but agreement with experiment degrades at intermediate energies. The balanced approach, found useful for electron processes, does not work for Compton processes at high energy, while an unbalanced approximation works for photon processes at high energy, but not for (e,3e)(e,3e) at intermediate energies.