2016/09/30 by Brendan M McLaughlin
Physics and Astronomy · #physics.atom-ph #astro-ph.EP
paper · pdf · doi:10.1093/mnras/stw2520
12 pages, 5 figures, 3 tables., accepted for publication in MNRAS. arXiv admin note: text overlap with arXiv:1412.8715
arxiv created 2016/09/30 · arxiv updated 2016/10/12
Absolute photoionisation cross sections for the Cl+ ion in its ground and the metastable states; 3s2 3p4 3P2,1,0, and 3s2 3p4 1D2, 1S0, were measured recently at the Advanced Light Source ALS) at Lawrence Berkeley National Laboratory using the merged beams photon-ion technique at an photon energy resolution of 15 meV in the energy range 19 -- 28 eV. These measurements are compared with large-scale Dirac Coulomb \it R-matrix calculations in the same energy range. Photoionisation of this sulphur-like chlorine ion is characterized by multiple Rydberg series of autoionizing resonances superimposed on a direct photoionisation continuum. A wealth of resonance features observed in the experimental spectra are spectroscopically assigned and their resonance parameters tabulated and compared with the recent measurements. Metastable fractions in the parent ion beam are determined from the present study. Theoretical resonance energies and quantum defects of the prominent Rydberg series 3s2 3p3 nd, identified in the spectra as 3p→ nd transitions are compared with the available measurements made on this element. Weaker Rydberg series 3s2 3p3 ns, identified as 3p → ns transitions and window resonances 3s3p4 (4P)np features, due to 3s → np transitions are also found in the spectra.