Cascade versus shake-off satellite Auger transitions in the Ar L - MM spectrum

Abstract

The - MM Auger spectra of argon have been created bombarding the sample gas by either 2 keV electrons or 398 eV and 315 eV photons. The 2p photoionization created by 315 eV photons may be accompanied by a simultaneous excitation of another electron to an unoccupied orbital or to the continuum. High-energy electrons and 398 eV photons can ionize the 2s subshell which may lead to the - - MM[M] satellite Auger transitions. Semi-empirical kinetic energies of the - MM[M] satellite Auger transitions have been estimated with the aid of MCDF calculations, the 2p shake-up spectrum, the - Coster - Kronig spectrum and the final-state binding energies from optical data. Intensities of the transitions have also been calculated by using a MCDF code. A comparison of the semi-empirical and observed energies with the calculated and observed intensities has allowed us to assign a manifold of the satellite peaks in the measured spectrum. We have also investigated the changes in intensity distribution of satellites in passing from cascade satellites to those created via shake-off processes accompanying photoionization.