Photoionization study of Kr+ and Xe+ ions with the combined use of a merged-beam set-up and an ion trap

Photoionization cross sections of halogen-like Kr+ and Xe+ ions have been measured in the photon energy range extending up to 15 eV above the threshold. Two different devices were used, a merged-beam set-up and an ion trap. Combination of the two techniques allows for the extraction of the pure ground state ionization cross section on an absolute scale. Multiconfiguration Dirac-Fock calculations reproduce the magnitude of the direct photoionization cross sections well.