Photoionization leading to the Al2+ 3l states from the ground state of Mg-like Al+ ion

Photoionization cross sections leading to the Al2+ 3l states from the S-1 ground state of the Mg-like All have been calculated using the eigenchannel R-matrix method. The calculations have been performed in LS coupling using a configuration interaction for the target states as well as for the full atomic wave functions. The lower members of autoionizing Rydberg series converging to the Al2+ 3l thresholds are identified. The present calculations with good agreement between length and velocity gauges are compared with the available previous results of the Opacity Project and experimental measurements.