Quasiresonant inelastic X-ray scattering: comparison of Compton and resonant terms

The contributions to inelastic X-ray scattering (IXS) spectra from the Compton scattering and X-ray resonant Raman scattering processes are theoretically compared. It is found that in the case of the atoms from Ni to Ge the main contribution to the IXS cross section originates from the process associated with the formation of the intermediate virtual state (with 1s vacancy) even when the incident photon energy is (several keV) less then the K absorption edge. The double differential cross section is expressed in terms of s, p and d partial local densities of electron states.