Two-electron photoionization of helium

Abstract
Cross sections of such processes as double photoionization and photoionization accompanied by excitation of He-like atomic systems are investigated in the limit of high, but still not relativistic, photon energies. In addition to total cross sections electron energy and angular distributions are also obtained. Coulomb wave and Green functions were employed in the momentum representation. Results for the total double ionization cross section as a function of photon energy are close to those obtained by predecessors with much more complicated ground state wavefunctions. The cross section of ionization with simultaneous excitation differs considerably from those obtained before. Angular and energy distributions of ionized electrons, are, to this extent, investigated for the first time.