Resonant x-ray Raman scattering and the infrared divergence of the Compton effect

Absolute values for the differential cross section $\frac{d\sigma }{d\Omega d\omega }$ of Cu $K\alpha$ x rays inelastically scattered from the series of elements Ni-Ge are presented for the region 2.5-8 keV. These data display the resonance x-ray. Raman effect discovered by Sparks, and are also in very good qualitative agreement with a model H-atom calculation by Gavrila and Tugulea which predicts that at still lower energies the scattering cross section diverges.