Doubly-Excited States of Atoms

Absolute partial photoionization cross sections, photoelectron and fluorescence angular distribution parameters of rare-gas atoms in the vicinity of the ns-subvalence thresholds are computed with the high accuracy. The np- and ns- main lines, and ns2 np4 n'(d/s)- satellite lines are taken as the objects of joint theoretical and experimental analysis. Results of calculations are compared with the recent experimental results obtained by means of the photon-induced fluorescence spectroscopy (PIFS). The interference between direct photoionization pathway and photoionization via excitation and subsequent autoionization of intermediate resonances is taken into account. The detailed classification of the individual influence of different relativistic and many-electron correlation effects (such as spin-orbit interaction, interchannel interactions between continuum state, and interaction between overlapping discrete states via autoionization continua) is performed on the base of computed spectra. Performed calculations resulted in the assignment of the majority of prominent resonances observed in the experimental cross sections of Ne, Ar, Kr and Xe atoms to the ns1 mp singly- and ns2 np4 n'(d/s)mp doubly-excited states. In many cases theoretical assignment was done for the first time.

Cooperations: Prof. Dr. A. Ehresmann (Universitat Kassel, Germany),
Prof. Dr. H. Schmoranzer ( University of Kaiserslautern, Germany),
Prof. Dr. K.-H. Schartner (University of Giessen, Germany),
Prof. Dr. V.L. Sukhorukov, Prof. Dr. I.D. Petrov and Prof. Dr. B.M. Lagutin
(Rostov State University of Transport Communications, Rostov-on-Don, Russia)
Status: completed