Abstract
We report new calculations of the transition probabilities for double electron photo-excitations near the KM edge in atomic Argon in the energy range 3220–3238 eV. The calculations were performed to study the X-ray photoabsorption spectrum of Argon near the KM edge using Multi-configurational Dirac-Hartee Fock method. Configuration interaction calculations showed that excitations to the doubly excited state [1s3p]3d2 is almost small compared to [1s3p]4p2 excitations, thus [1s3p]4p2 is the dominant transition in this energy range. The transition probabilities were convoluted into Breit-Wigner line shapes and compared to previous measurements of the X-ray photoabsorption spectrum of Argon near the KM edge, the comparison showed good agreement with experiment. The results of the calculations presentded herein therefore shed light on understanding of near KM edge features, and thereby the preferred excitation channels of the atom.
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•New calculations of the transition rates for double excitations near the KM edge of Argon using the MCDF method.•The transition rates were convoluted into Breit-Wigner line shapes.•[1s3p]4p2 double electron excitations were found to be dominant in this energy range.•Good agreement between the calculations and experiment was found.