Journal article

Publication year: 2024

Journal: Physical review A

Volume number: 110

Issue number: 6

ISSN: 2469-9926

eISSN: 2469-9934

DOI Link: https://doi.org/10.1103/PhysRevA.110.062802

Publisher: American Physical Society

Abstract: 
Within a joint experimental and theoretical research project, single photoionization of He-like B3+ ions was investigated in the energy range from approximately 250 to 1200 eV. With the parent-ion beam in the experiment containing both 1s2 1 S ground-state and 1s2s 3 S metastable B3+ ions, double-core-hole resonances could be studied. Two series of hollow resonant states were observed, one populated by K-shell double excitation 1s2 1 S-* 2 n ' 1 P ( = s, p ; ' = p, s ; n = 2, 3, ..., 6) at photon energies up to about 510 eV, the other by K-shell single excitation 1s2s 3 S-* 2 n ' 3 P ( = s, p ; ' = p, s ; n = 2, 3, ..., 6) at energies up to about 310 eV. High resolving powers up to approximately 29 000 were achieved. The relativistic many- body perturbation theory was employed to determine level-to-level cross sections for K-shell excitation with subsequent autoionization. The resonance energies were calculated with inclusion of electron correlation and radiative contributions. The energy uncertainties of the most prominent resonances are estimated to be below f 1 meV. Convergent close-coupling (CCC) calculations provided single-photoionization cross sections sigma 34 for B3+ including the resonant and nonresonant channels. Apart from the resonances, sigma 34 is dominated by direct ionization in the investigated energy range. The contribution sigma 34 dir of the latter process to sigma 34 was separately determined by using the random-phase approximation with exchange and relativistic Hartree-Fock calculations which agree very well with previous calculations. Direct ionization of one electron accompanied by excitation of the remaining electron was treated by the CCC theory and found to be a minor contribution to sigma 34 .

Harvard Citation style: Müller, A., Hillenbrand, P., Wang, S., Schippers, S., Lindroth, E., Trinter, F., et al. (2024) Double-K-hole resonances in single photoionization of He-like B3+ions, Physical review A, 110(6), Article 062802. https://doi.org/10.1103/PhysRevA.110.062802

APA Citation style: Müller, A., Hillenbrand, P., Wang, S., Schippers, S., Lindroth, E., Trinter, F., Seltmann, J., Reinwardt, S., Martins, M., Kheifets, A., & Bray, I. (2024). Double-K-hole resonances in single photoionization of He-like B3+ions. Physical review A. 110(6), Article 062802. https://doi.org/10.1103/PhysRevA.110.062802