Valence-shell single photoionization of Kr$^{+}$ ions: Experiment and Theory

TL;DR

This study combines high-resolution experimental measurements and advanced theoretical calculations to analyze the photoionization process of Kr$^+$ ions, revealing detailed resonance structures and providing benchmark data.

Contribution

It presents the first high-resolution experimental photoionization spectra of Kr$^+$ ions and compares them with state-of-the-art Dirac-Coulomb R-matrix calculations.

Findings

Identification of multiple autoionizing Rydberg resonances.

Accurate tabulation of resonance energies and quantum defects.

Benchmarking of experimental data against theoretical models.

Abstract

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.