Journal article

Authors list: Müller, A; Hillenbrand, PM; Wang, SX; Schippers, S; Reinwardt, S; Martins, M; Seltmann, J; Trinter, F; Bray, I; Fursa, DV; Kheifets, AS

Publication year: 2025

Journal: Physical review A

Volume number: 111

Issue number: 5

ISSN: 2469-9926

eISSN: 2469-9934

DOI Link: https://doi.org/10.1103/PhysRevA.111.053108

Publisher: American Physical Society

Abstract: 
Single and double photoionization of the Li-like B2+(1s22s2S) ion were studied both experimentally and theoretically in the energy range from approximately 250-1200 eV. The cross section a23 for net single ionization in that range is dominated by direct removal of one K-shell electron, a process that is described very well by theory. Accordingly, measured yields of B3+ photoproducts were normalized to theory to obtain absolute cross sections a23. Aside from direct single ionization, there are additional contributions to a23 from photoabsorption resonances. The parameters of the Fano profile of the most prominent of these resonances, the triply excited 2s22p 2P state, were calculated by employing the convergent close coupling (CCC) approach and the theoretical results were experimentally verified. Using the normalization procedure obtained from the investigation of single ionization, also the measured yields of B4+ product ions could be put on an absolute cross-section scale. The resulting experimental cross section a24is in good accord with the CCC calculations revealing unexpectedly strong contributions that arise from ionization with excitation of B2+(1s22s2S) forming intermediate autoionizing B3+(nt n'I') levels, which subsequently decay to B4+ by Auger-electron emission. In addition, contributions to a24 from resonant excitation of B2+(nt n'I' n''I'') with n, n', n'' 2 could be identified. These triply excited resonances with an empty K shell can decay by simultaneous or sequential emission of two electrons and thus contribute to net double photoionization of the parent B2+ ion.

Harvard Citation style: Müller, A., Hillenbrand, P., Wang, S., Schippers, S., Reinwardt, S., Martins, M., et al. (2025) Single and double photoionization of the Li-like B2+ion: Strong ionization-excitation contributions, Physical review A, 111(5), Article 053108. https://doi.org/10.1103/PhysRevA.111.053108

APA Citation style: Müller, A., Hillenbrand, P., Wang, S., Schippers, S., Reinwardt, S., Martins, M., Seltmann, J., Trinter, F., Bray, I., Fursa, D., & Kheifets, A. (2025). Single and double photoionization of the Li-like B2+ion: Strong ionization-excitation contributions. Physical review A. 111(5), Article 053108. https://doi.org/10.1103/PhysRevA.111.053108