Closing of Coster–Kronig transitions and variation of fluorescence and Auger yields in isonuclear sequence of tungsten

Abstract

The dependence of Auger yields, partial and total Auger widths of levels, total radiative widths and fluorescence yields on the ionization degree is considered for the ions of tungsten. The calculations are performed for the Ni subshells in single configuration quasirelativistic approximation. The intervals of ionization stages at which the Coster–Kronig transitions are energetically possible or partially possible are determined. It is shown that the partially possible Coster–Kronig transitions between overlapping initial and final configurations can take place in several neighbouring ions successively. According to our calculation results, the nonradiative decay of vacancies in Ni subshells becomes impossible from ionization stage q = 21. The total Auger width depends weakly on ionization degree up to its values q = 8, ...,11, but for higher ions changes non-monotonically due to closing of Coster–Kronig transitions. The fluorescence yield shows the similar dependence on q. Keywords: Coster–Kronig transitions, Coster–Kronig yield, fluorescence yield, Auger width, Tungsten ions