The ionization of Mg 3s and 2p and He 1s has been studied in (e, 2e) experiments at about 1000 eV incident energy and 20 eV ejected electron energy for a momentum transfer between 0.5 and 2.1 au. The comparison with the predictions of the distorted wave Born approximation model shows a generally good agreement between experiment and theory. The differences observed between the He and Mg angular distributions can be explained as an initial state effect and are attributed to the differences between the He 1s and Mg 3s wavefunctions in the momentum space.

The ionization of Mg 2p by electron impact has been studied at about 400 and 1000 eV incident energy and small momentum transfer via ͑e ,2e͒ experiments. Two kinematical conditions have been chosen in order to study the coincidence angular distribution in the case where either only the direct 2p ionization contributes or the decay of the 2p core hole plays a role, too. The results have been compared with distorted-wave Born approximation calculations.

No abstract

No abstract