X‐ray emission via Kα resonance complexes in gold ions

Abstract

The excitation energies from ground state for 63 fine structure levels of the terms belonging to 1 s2, 1snl, 2lnl′ (n = 2,3), 3l3l′ (l ≠ ≠l′) configurations of Au77+, as well as oscillator strengths for electric‐dipole‐allowed and intercombination transitions among the fine‐structure levels were theoretically evaluated. The important relativistic effects in intermediate coupling are incorporated by means of the Breit–Pauli Hamiltonian. Extensive comparisons are performed with several approximations and previous data sets in order to size up contributing effects and to estimate accuracy ratings. The atomic excitation is obtained by electron impact in close coupling approach. For optically allowed transitions, the electron‐impact collision strengths at collision energy up to 80 keV are reported. The results are relevant to the laboratory and astrophysical plasmas.