He-like ions colliding on H2 an analysis of the 1s23131' electron spectra

The authors present energy spectra of Auger electrons due to autoionisation of doubly excited Be-like states with configuration 1s23l31' produced in collisions of the He-like N5+ and O6+ ions on H2 at impact energies ranging from 24 to 108 keV. The spectra are analysed using theoretically predicted energy levels and lifetimes. The theoretical values of Bachau et al (1989) are in excellent agreement with the experimental data. It is found that interferences between transitions from different states have to be taken into account to reproduce structures in the measured spectra satisfactorily. The fits yield populations for the various states. Changing the impact energy shows clear variations in the relative populations, especially an increase of the high L states with increasing impact velocity