A coincidence study of multiple-electron capture in 15N7+-Ar collisions

We present energy spectra of autoionization electrons resulting from collisions between fully stripped N-15(7+) ions and Ar in the energy range of 1-10 keV amu-1. These spectra have been measured in coincidence with charge-state analysed Ar ions. Observed populations of the various configurations are discussed in the framework of the classical overbarrier model. Our measurements suggest that target-ion excitation together with two-electron capture is an important process in collisions between bare N7+ ions and Ar. We find evidence that radiative stabilization of doubly excited N5+(4l, 4l') states is even stronger than was thought up to now.