1s shake-up excitations in Ge and GeO2 by high-energy x-ray photoemission spectroscopy

X-ray photoemission spectra of Ge and GeO2 have been collected using high-e nergy photons (E-gamma = 13.6 keV and E-gamma=11.85 keV). The experiment wa s carried out using a high brilliance undulator source of the European Sync hrotron Radiation Facility. The comparison between photoemission spectra at different energies and electron-energy-loss spectra allowed us to unambigu ously identify shake-up satellites of the Is photoelectron peak involving a dditional excitations of 3p and 3s electrons. These features are clearly vi sible in GeO2 at the energies of 152 eV and 208 eV above the 1s peak.