Measurements and Calculations of Photoionization Cross Sections of Multiply Charged Ions in Ground and Metastable States along the Isonuclear Series of Oxygen: O ²⁺ to O ⁴⁺

Abstract

In this paper, we present the first absolute measurements for photoionization of multiply charged oxygen ions: O^2+ and O^3+ in the ground state and in several metastable states, as well as relative data for O^4+. Multiconfiguration Dirac-Fock and relativistic R-matrix calculations were performed and are tested here by comparison\nwith experimental results. Our experimental and new theoretical results are also compared with the earlier theoretical data obtained in the R-matrix approximation to calculate photoionization cross sections\nover part of the isonuclear series of multiply charged oxygen ions.