Electron momentum density of graphite from (γ,eγ) spectroscopy

By the coincidental detection of an inelastically scattered hard X-ray photon and its recoil electron (i.e. a so-called (γ,eγ) experiment) cuts through the 3D-electron momentum density (EMD) of graphite have been measured and are compared with a theoretical EMD based on a pseudopotential calculation. Peak shifts of the EMD as a function of the electron emission angle are discussed by a detailed consideration of the scattering kinematics. Experiments have been performed at the European Synchrotron Radiation Facility (ESRF) at Grenoble, France.