Inner-shell photoionization of ground-state lithium: Theoretical calculation in the photon energy region below 130 eV including1snln′l′

Abstract

Calculations of 1s electron inner-shell photoionization from the 1s 2 2s 2 S e Li ground state have been performed using recent developments of the R-matrix code with a 19-term target representation for incident photon energies up to 130 eV. This photon energy range allows important resonances in the partial cross sections due to 1snlnЈlЈ autoionizing states to be obtained. Theoretical resonant results are compared with recent experimental measurements of Kiernan et al. ͓J. Phys. B 29, L181 ͑1996͔͒ in the 1s2l threshold region. Partial cross sections, branching ratios, and asymmetry parameters are also compared outside the resonant energy range with previous theoretical results of Lisini, Burke, and Hibbert ͓J. Phys. B 23, 3767 ͑1990͔͒, who used the R-matrix code with an 11-term target representation, as well as the corresponding experimental results of Ferret et al. ͓Phys. Rev. A 36, 3172 ͑1987͔͒, Langer et al. ͓Phys. Rev. A 43, 1652 ͑1991͔͒, and Cubaynes et al. ͑private communication͒.

Resonances in atomic photoionization

“…Both results agree closely with experiments. Also included in this table are the recent experiment of Kiernan et al (1996) using synchrotron radiation as well as the computation results from the R-matrix calculation of Vo Ky et al (1998a). The only experimental data available on the width for the 2 P 0 resonances are that of ½1sð2s2pÞ 3 P 2 P 0 by Mannervik and Cederquist (1985) (2.6(1) meV) and Pedrotti (1987) (3.2(6) meV).…”

“…The four lowest members of the 2 P 0 resonances are also investigated by Chen and Chung (1994) with highly accurate wave functions, the result agrees closely with that of Chung (1997a). No width information are given in Vo Ky et al (1998a). Most of these width are extremely narrow and are significantly smaller than the experimental resolution in the photoionization spectra.…”

“…For Li photoionization cross section below the Li þ 1s3l threshold, several experimental (Cant " u et al, 1977;Mehlman et al, 1978Mehlman et al, , 1982Kiernan et al, 1996;Ferrett et al, 1987) and theoretical (Vo Ky et al, 1998a;Lisini et al, 1990;Chung and Chang, 2000) studies are published. High resolution PICS spectra are obtained in a recent experiment (Kiernan et al, 1996).…”

“…No attempts have made to measure the absolute cross section data to my knowledge. Vo Ky et al (1998a) also presented results of resonance energy and cross section using R-matrix method. Due to the approximated ground state wave function, they have shifted the energy by 200 meV in making comparison with experiment.…”

Experimental study of linear magnetic dichroism in photoionization satellite transitions of atomic rubidium

“…These include the sudden approximation [7,13,15,16,20], random-phase approximation with exchange [11,18], perturbation theory [4,6,10,11], and the R-matrix method [5,19,21,22]. However, despite decades of research, agreement between the experiment and theory of conjugate satellites is still often considerably worse than for the main lines and monopole satellites.…”