Double atomic photoeffect in the relativistic domain: angular and energy distributions of photoelectrons

We study the double ionization of the atomic K-shell by a single photon in the relativistic energy domain. The differential and total cross sections o f the process are calculated. It is shown that the ratio of the cross secti ons of double and single ionization increases with the photon energy, tendi ng to the limit 0.34/Z(2), where Z is the atomic number or the nuclear char ge. The formulas are found to be valid for Z much greater than 1 and alpha Z much less than 1, where alpha = 1/137 is the fine-structure constant. (C) 1998 American Institute of Physics. [S1063-7761(98)00111-5].