Absolute single photoionization cross-section measurements of Rb2+ ions: Experiment and theory

Absolute single photoionization cross-section measurements of Rb2+ ions were performed using synchrotron radiation and the photo-ion, merged-beams technique at the Advanced Light Source at Lawrence Berkeley National Laboratory. Measurements were made at a photon energy resolution of 13.5 +/- 2.5 meV from 37.31 to 44.08. eV spanning the P-2(3/2)0 ground state and P-2(1/2)0 metastable state ionization thresholds. Multiple autoionizing resonance series arising from each initial state are identified using quantum defect theory. The measurements are compared to Breit-Pauli R-matrix calculations with excellent agreement between theory and experiment.