Post–prior discrepancies in the continuum distorted wave–eikonal initial stateapproximation for ion–helium ionization

Abstract

We have explored post–prior discrepancies within continuum distortedwave–eikonal initial state theory for ion–atom ionization. Although there are nopost–prior discrepancies when electron–target initial and final states are exactsolutions of the respective Hamiltonians, discrepancies do arise for multielectronictargets, when a hydrogenic continuum with effective charge is used for the finalelectron–residual target wavefunction. We have found that the prior versioncalculations give better results than the post version, particularly for highlycharged projectiles. We have explored the reasons for this behaviour and foundthat the prior version shows less sensitivity to the choice of the final state.The fact that the perturbation potentials operate upon the initial statesuggests that the selection of the initial bound state is relatively moreimportant than the final continuum state for the prior version.