RESONANCE EXCITATION CROSS-SECTION OF AL-LIKE P2+ AND S3+ AT LOW ENERGIES

Resonance excitation (RE) cross sections of the ground state (3s2 3p)2 P configuration of Al-like P2+ and S3+ ions are calculated at low ener gies. Contributions from the multiplets of the first excited state 3s2 3p are also included. The Auger and radiative transition probabilitie s were calculated using single configuration non-relativistic Hartree- Fock wavefunctions in LS coupling. There are eight different modes of excitation for the initial ground state configuration. The resonance e xcitation cross sections, for both ions, were found to be large, as mu ch as a factor of 10(3) larger than that of dielectronic recombination (DR), mainly because of the smallness of the fluorescence yield of th e resonance levels. It was also found that the resonance elastic scatt ering is dominant, and that the RE cross section decreases with increa sing atomic number and vice versa for the DR process.