Valence-shell single photoionization of Kr$^{+}$ ions: Experiment and   Theory
  Photoionization of Kr$^+$ ions was studied in the energy range from 23.3 eV to 39.0 eV at a photon energy resolution of 7.5 meV. Absolute measurements were performed by merging beams of Kr$^+$ ions and of monochromatized synchrotron undulator radiation. Photoionization (PI) of this Br-like ion is characterized by multiple Rydberg series of autoionizing resonances superimposed on a direct photoionization continuum. Resonance features observed in the experimental spectra are spectroscopically assigned and their energies and quantum defects tabulated. The high-resolution cross-section measurements are benchmarked against state-of-the-art theoretical cross-section calculations from the Dirac-Coulomb R-matrix method. 
G. Hinojosa, A. M. Covington, G. A. Alna'Washi, M. Lu, R. A. Phaneuf,   M. M. Sant'Anna, C. Cisneros, I. \'Alvarez, A. Aguil...
physics.atom-ph astro-ph.EP physics.chem-ph