High Energy Limit of the Two-Electron Photoionization Processes in the Helium-Like Systems

We present the analysis of double photoionization and of ionization accompanied by excitation of the helium atom and helium-like ions. The high-energy limit corresponding to the ultrarelativistic energies transferred to the atom is considered. The cross-sections ratios are expressed through certain integral parameters of the wave function of the initial state. The calculations with the wave function obtained earlier by Correlation Function Hyperspherical Harmonic Method are carried out. The dependence of the relative role of the quasifree mechanism on the nuclear charge Z in ionization of the ground state and of the excited n's states is analyzed