Characterization of the doubly excited autoionizing states in B³⁺, N⁵⁺ and F⁷⁺ ions

In this work, we theoretically investigate the doubly excited autoionizing states (DEAS) in the Helium-like B³⁺, N⁵⁺ and F⁷⁺ ions [1] by using a B-spline based spectral approach [2,3] combined with the complex rotation method [4,5]. The recent advent of X-ray free-electron lasers opens the possibility for a controlled production of the DEAS in a variety ground-state and metastable state He-like ions to investigate their role and contribution in the ionization process.

Our method provides the exact X-ray photon energies needed to trigger the production of the DEAS in the energy spectra and their lifetimes decay. The data generated by the present method will be a support to the future experiments investigating the DEAS in the He-like ions.  The method also has the advantage to give access to the information about the angular correlations pattern between the two electrons in each DEAS which allows the classification of all the produced states into distinct resonant series.

[1] S. Laulan, M.-A. Albert, S. Barmaki, Eur. J. Phys. D (under revision).

[2] S. Barmaki, M.-A. Albert, S. Laulan, Chem. Phys. 517, 24 (2019)  

[3] S. Barmaki, M.-A. Albert, S. Laulan, J. Phys. B: At. Mol. Opt. Phys. 51, 105002 (2018)  

[4] S. Laulan, M.-A. Albert, S. Barmaki, J. Electron Spectrosc. Relat. Phenom. 271, 147429 (2024)

[5] S. Barmaki, M.- A. Albert, S. Laulan, Phys. Scr. 95, 055403 (2020)