Experimental and theoretical study of the Auger cascade following 3d→5p photoexcitation in Kr

Resonant Auger transitions from the 3d-15p photoexcited states in Kr to the 4s-14p-15p and 4s-25p levels and subsequent Auger decay to the 4p4 and 4s4p5 states of Kr2+ are studied by means of angle-resolved electron spectroscopy. The angular anisotropy parameters β are determined for most of the prominent lines in the spectrum of emitted electrons. It is found that the first-step spectator transitions are strongly anisotropic, while the second-step participator transitions are almost isotropic. Extensive multiconfiguration Dirac-Fock calculations are performed which include correlations in all of the states involved. Noticeable improvements are achieved in comparison with early calculations. The energy position of the main spectral lines and their intensities are described satisfactorily. It turns out that the interference effects due to coherent excitation of resonances influence the anisotropy of the Auger emission significantly. The calculated β parameters agree very well with the experiment.