Absolute Auger rates, relative intensities and angular distribution of the KLL spectra of Auger electrons from alkali atoms

Abstract

The absolute Auger rates, relative intensities and the angular anisotropy coefficients of Auger electrons have been calculated for the KLL Auger spectra of the alkali atoms Na, K, Rb, and Cs. Where in closed-shell atoms the KLL Auger lines have to be isotropic, this is no longer valid for certain Auger transitions in open-shell systems. The angular anisotropy coefficients are calculated for open-shell atoms for the first time applying an intermediate coupling scheme. The relativistic multiconfigurational Dirac-Fock model including Breit-QED and exchange interaction is used for the calculation of the Auger matrix elements. The results for the Auger rates and intensities are compared with earlier theoretical predictions and experimental data. The angular anisotropy parameters are discussed together with theoretical predictions in the LS coupling. Large angular anisotropy coefficients have been found for the KL1L2.3 Auger transitions of all alkali atoms. In particular, an observable angular anisotropy can be predicted for the Auger transitions of potassium.