Double ionization and excitation ionization in the Compton scattering of high-energy photons for metastable states of heliumlike ions

Double ionization and excitation ionization in Compton scattering for heliu mlike ions in metastable states are investigated. The electron energy distr ibution for double ionization and the total cross sections for both process es are calculated. The calculations are carried out in the zeroth order of perturbation theory with respect to electron-electron interaction, using Co ulomb wave functions as the first approximation. The resulting equations ar e valid only in the high-energy nonrelativistic range. It is assumed that Z much greater than 1, but alpha Z much less than 1 (Z is the charge of the nucleus, and alpha is the fine-structure constant). (C) 1999 American Insti tute of Physics. [S1063-7761(99)00112-2].