Formation of Kr3+via core-valence doubly ionized intermediate states

Abstract

The time-of-flight photoelectron-photoion coincidence technique has been used to study single-photon $3{d}^{9}4{p}^{5}$ core-valence double ionization of Kr and subsequent Auger decay to triply charged states associated with the $4{s}^{2}4{p}^{3}$ and $4{s}^{1}4{p}^{4}$ configurations. The photon energy used was $h\ensuremath{\nu}=150$ eV. Multiconfiguration Dirac-Fock calculations were performed both for the doubly ionized intermediate states and the triply ionized final states. The intermediate states of Kr${}^{2+}$ are observed between 120 and 125 eV, whereas the final states of Kr${}^{3+}$ are observed between 74- and 120-eV ionization energy. Assignments of all structures are made based on the present numerical results. The calculated Auger rates give a detailed explanation of the relative line strengths observed.