Resonant inelastic scattering of an x-ray photon by the argon atom nearKandKM23ionization thresholds

Abstract

The influence of many-particle effects on the absolute values and the shape of doubly differential cross section of resonance inelastic scattering of a linearly polarized x-ray photon by the free Ar atom near $K$ and $K{M}_{23}$ ionization thresholds is studied theoretically. Shown is the evolution of spatially extended profile of the scattering cross section into the principal $K{\ensuremath{\beta}}_{1,3}$ and satellite $K{\ensuremath{\beta}}^{V}$ structures of the $\mathrm{Ar}\phantom{\rule{0.3em}{0ex}}K\ensuremath{\beta}$ emission spectrum. The calculations are performed in nonrelativistic Hartree-Fock approximation for the atomic wave functions and in the dipole approximation for the anomalous-dispersion scattering amplitude. The following many-particle effects are included: radial relaxation of electron shells, correlational loosening, vacuum correlations, spin-orbital, and multiplet splitting, configuration interaction in doubly excited atomic states, Auger and radiative decays for the vacancies produced. Calculations results are predictions while for the case of the incident photon energies of 3199.2 and $3245.9\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ they compare well with the results of the synchrotron experiment of Deslattes et al. [Phys. Rev. A 27, 923 (1983)] on measuring the x-ray $K\ensuremath{\beta}$ emission spectrum of the free Ar atom.