Alignment of photoions for the autoionization analysis of doubly excited rare gas valence shells

Rare gas valence shell satellites excited by linearly polarized synchrotron radiation are produced exclusively through electron correlations. In the near threshold range they show a strong enhancement through the autoionization of doubly excited Rydberg states. Studying the fluorescence decay of the excited photoions we derived the alignment parameter A20, which depends on the dynamics of the decay process. Here we report on the population of the Ne+ 2p42PJ and 4PJ finstructure states. While the 2PJ states show interference between direct population and autoionization, the 4PJ states to the contrary, are populated only through autoionization. This is a clear indication for singlet/triplet mixing of the more closely investigated Ne 2p4(3P) 3p 2P3/2,1/2-ns, nd-Rydberg-states, since the population of the 4PJ-states is forbidden in LS-coupling. Corresponding autoionization processes were studied for the heavier rare gases in order to reveal systematic features