Photoionization of Be-like neon (Ne VII) from the low-lying states: Energies, widths, branching ratios, and oscillator strengths of the1s−2presonances

Abstract

Seventeen-state close-coupling calculations are performed on the photoionization near the 1 s-2 p resonance region from the terms belonging to the configurations 1s 2 2s 2 ,1 s 2 2s2p, and 1s 2 2p 2 , of Be-like neon ions, Ne VII. The calculations include the total and partial photoionization cross sections and the contributions of the main ionization channels to the partial cross sections. The resonance energies, widths, and branching ratios of the 1s-2 p core-excited states are determined from these cross sections. The resonance oscillator strengths of the corresponding 1s-2 p transitions from Ne VII low-lying states are also obtained by integrating the photoionization cross sections. Our theoretical resonance energies, widths, and branching ratios are compared with existing experiments on the Auger spectra and other theoretical results. The calculated resonance energies are in rather good agreement with the latest experiment on the Auger spectra. For the autoionization width, good agreement is also found with recent theoretical results wherever available obtained using a saddle-point complex-rotation method.