Theoretical studies on photoionization of Na-like iron ion

Abstract

The ionization energies and the corresponding photoionization cross sections from the 1s, 2s, 2p and 3s subshells of Fe15+ are calculated systematically using a newly developed program RERR06 for the first time, which is based on the widely used GRASP92 and RATIP packages. In the calculation, the effects of configuration interaction and orbital relaxation have been considered. As a result, the shake-up processes accompanied by the main photoionization processes have been treated as uni.ed. It is found that the present calculations for ionization energies are in good agreement with existing data and the photoionization (PI) cross sections for the 2pelectron are also in good accordance with recent computations. The contribution from the shake-up processes are found to be not important for the photoionization of Fe15+, but an enhancement feature is noticed for the 2p to 3p shake-up process accompanied by the PI of the 3s electron.