The near threshold photoionization cross section of atomic scandium

Abstract

A photoionization cross-section calculation for atomic scandium, which has the LS coupled ground-state configuration ([Mg] 3p(6)3d4s(2)) [D-2] is performed in the formalism of many-body perturbation theory for photon energies ranging from the first ionization threshold to 70 eV. We considered excitations from 3p, 3d and 4s subshells, which resulted in a total of 32 partial photoionization final states in LS coupling. Our results indicate that the total cross section is dominated by the 3p(6)3d4s(2) -> 3p(6)3d4s(D-3)kp P-2 partial cross section below the 3d threshold at 7.29 eV, and by 3p -> 3d resonance excitations in the photon energy range of 27-40 eV. Good qualitative agreement with experiment is found.