Photoionization cross sections for the trans-iron element Se+ from 18 to 31 eV

Abstract

Absolute photoionization cross-section calculations are presented for Se+ using large-scale close-coupling calculations within the Breit–Pauli and Dirac–Coulomb R-matrix approximations. The results from our theoretical work are compared with recent measurements (Esteves 2010 PhD Thesis publication number AAI3404727, University of Reno, NV, USA; Sterling et al 2011 J. Phys. B: At. Mol. Opt. Phys. 44 025701; Esteves et al 2011 Phys. Rev. A 84 013406) made at the advanced light source (ALS) radiation facility in Berkeley, CA, USA. We report on results for the photon energy range 18.0–31.0 eV, which spans the ionization thresholds of the 4So3/2 ground state and the low-lying 2Do5/2,3/2 and 2Po3/2,1/2 metastable states. Metastable fractions are inferred from our present work. Resonance energies and quantum defects of the prominent Rydberg resonances series identified in the spectra are compared for the 4p → nd transitions with the recent ALS experimental measurements made on this complex trans-iron element.