Theoretical study of photoionization cross sections of Al-like Sc

Photoionization (PI) cross sections of the ground state 3 s 2 3 p 2 P ° 1/2 and metastable state 3 s 2 3 p 2 P ° 3/2 of Al-like Sc are investigated using the Dirac R -matrix method. The current energy levels and radiative transition rates are consistent with experimental results and previous theory. Our calculated ionization energies of the ground and metastable states are in accordance with the experimental values. The PI cross sections show good agreement between length and velocity forms. Partial-wave contributions to the total PI of ground and metastable states are discussed. Moreover, the PI cross sections are dominated by a large number of resonances from the Rydberg series of autoionizing states. In addition to providing data for the Opacity Project TOPbase, the present work promotes plasma simulation and diagnosis. Graphical abstract