Inelastic x-ray scattering at intermediate momentum transfer: Fluorescence spectrum and search for infrared divergence in scattered x-ray spectra

We have measured the ratio of the fluorescence line intensities in the decay of a copper K-shell vacancy created in an inelastic-scattering event at intermediate momentum transfer. The measured value of the ratio of K{β} line intensity to K{α} line intensity is 0.07±{}0.05, consistent with the value observed for excitation by photoabsorption. We also present data on the spectrum of x rays inelastically scattered from the copper K shell in a search for the predicted infrared divergence in the atomic scattering cross section. We find that the observed spectrum at low scattered x-ray energy in this and previous work is well described by secondary x rays produced in bremsstrahlung emission by photoelectrons.