The 4p6 core excited autoionising states in strontium:: Classification and excitation dynamics

The ejected electron spectra corresponding to the electron decay of the 4p(5)n(1)l(1)n(2)l(2)n(3)l(3) low-lying autoionising states in strontium atoms were measured in the impact energy range from the excitation threshold of states up to 200 eV. By using the results of single-configuration Hartree-Fock (HF) calculations, six ejected electron lines with the lowest excitation thresholds were attributed to the decay of the (4P(5)4d5s(2))(3) P-0,P-1,P-2 and F-3(2,3,4) autoionising states. For the P-3(1,2) and F-3(4) states the excitation functions were obtained at an incident electron energy resolution of 0. 15 eV. In all excitation functions the strong near-threshold structure was revealed for the first time. The origin of the structure was attributed to the decay of short-lived states from the 4p(5)5s(2)4d(2) configuration of Sr- ion. The cascade population of the P-3(0,1,2) and F-3(2,3,4) states was considered by Ming the HF energies and decay probabilities for the 4p(5)5s(2)5p levels.