Resonant fluorescence emission from the Ge and Cu valence band

Working out the calculation of the double differential scattering cross section for resonantly excited X-ray emission from valence bands, one ends up with a law of momentum conservation, combining Bloch-k-vectors of the envolved electrons and the incoming and outgoing photon. This leads to a rich structure of the fluorescence line that reveals properties of the underlying electronic band structure. First experiments in the hard X-ray region on Ge and Cu are presented, showing, that momentum conservation in the resonant absorption-emission process holds. (orig.)