Inner-Shell Photoionization of Alkaline-Earth-Metal Atoms

The photoionization cross sections, branching ratios, and angular-distribution asymmetry parameters for the inner shells of alkaline-earth-metal atoms have been calculated using the relativistic random-phase approximation and the relativistic random-phase approximation modified to include relaxation effects. Our main purpose is to determine whether relaxation effects are important throughout the group IIA of alkaline-earth metals. Comparisons are made between relaxed and unrelaxed results. Results for beryllium and strontium are compared with experiments. Strong relaxation effects are noted for the ionization of 3d electrons in barium. © 1993 The American Physical Society