Orbital Relaxation Effects in the Calculation of Aluminum K_α Absorptions

A recent experimental K_α transmission spectrum of an aluminum plasma is theoretically studied by a detailed level accounting model. It is found that the orbital relaxation effects of the K- and L-shell orbitals should be considered to calculate accurate line positions and strengths. To do this the initial and the final radial wave functions of K_α lines are respectively optimized by solving the full relativistic Dirac-Fock equation. Extensive configuration interaction calculations are performed to obtain the energy levels and the oscillator strengths. It is shown that both the line positions and the line strengths agree quite well with experiment when the orbital relaxations are considered.