Photoemission spectra for gold for 15≤hv≤90 eV and the X-ray limit

Photoemission spectra for gold have been measured for photon energies 15≤hv≤90 eV using synchrotron radiation. We observe the transition from the 'band structure' regime (hv≲30 eV) where spectra are strongly modulated by matrix elements to the high energy regim (hv≳30 eV) where spectra reflect structure in the single-particle density of states. © 1973.