Near-K-edge single, double, and triple photoionization of C+ ions

TL;DR

This study provides detailed experimental measurements of single, double, and triple photoionization of C+ ions near the K-edge, including resonance linewidths, cross sections, and decay rates, with high energy resolution.

Contribution

It offers the first high-resolution experimental data on multi-electron ionization processes of C+ ions near the K-edge, comparing results with theoretical calculations.

Findings

Resonance natural linewidths determined at 12 meV resolution

Absolute cross sections and transition parameters measured

Partial agreement with theoretical models despite simple atomic structure

Abstract

Single, double, and triple ionization of the C+ ion by a single photon have been investigated in the energy range 286 to 326 eV around the K-shell single-ionization threshold at an unprecedented level of detail. At energy resolutions as low as 12 meV, corresponding to a resolving power of 24000, natural linewidths of the most prominent resonances could be determined. From the measurement of absolute cross sections, oscillator strengths, Einstein coefficients, multi-electron Auger decay rates and other transition parameters of the main K-shell excitation and decay processes are derived. The cross sections are compared to results of previous theoretical calculations. Mixed levels of agreement are found despite the relatively simple atomic structure of the C+ ion with only 5 electrons. This paper is a follow-up of a previous Letter [M\"uller et al., Phys. Rev. Lett. 114, 013002 (2015)].