Angle resolved Photoemission from Cu single crystals; Known Facts and a few Surprises about the Photoemission Process

We present angle resolved photoemission spectra for Cu(100) and Cu(111) singly crystals in normal emission geometry, taken at tightly spaced intervals for photon energies between 8 eV and 150 eV. This systematic collection of spectra gives unprecedented insight into the influence of the final states to the photoemission process as well as the band structure and lifetimes of highly excited electrons in Cu.