The $\mathsf{1s\rightarrow2p}$ resonance photoionization from the low-lying states of $\mathsf{O^ + }$

Abstract.

Thirty-state close-coupling calculations have been performed for the photoionization of O ⁺ near the $1s\rightarrow2p$ resonance energy region from the terms belonging to the configurations of 1s ²2s ²2p ³ and 1s ²2s2p ⁴. Total and partial photoionization cross-section and the contributions of the main ionization channels to the partial cross-section are calculated to obtain the resonance energies, autoionization widths and Auger branching ratios of the $1s\rightarrow2p$ core-excited states. The resonance oscillator strengths of the $1s\rightarrow2p$ transitions are also obtained by integrating the photoionization cross-section. The radiative widths of the $1s\rightarrow2p$ transitions can be obtained from the oscillator strengths. The results show that the radiative widths are generally three orders of magnitude smaller than the corresponding autoionization widths and therefore contributes little to the natural widths.