Electric Octupole Transitions in Ag-like High-Z ions

ORAL

Abstract

We report measurements and identifications of electric octupole (E3) transitions between the 4f7/2,5/2 and 5s1/2 levels of Ag-like W27+, Re28+, and Ir30+ ions. We used a flat-field grazing-incidence extreme-ultraviolet (EUV) spectrometer on the electron beam ion trap (EBIT) of the National Institute of Standards and Technology (NIST) to record spectra that included lines from Ag-like and neighboring charge states. Our results confirm the occurrence of E3 transitions in W27+, first reported by Sakaue et al. [1], and provide higher precision results for the wavelengths that our multi-configuration Dirac-Fock (GRASP2K) calculations can reproduce.

Our collisional-radiative calculations based on the NOMAD [2] and FAC [3] codes give an insight into the population kinetics for Ag-like ions of heavy elements, including the electron density dependence of the relative line intensities. Our measurements of the forbidden lines in highly charged ions provide information on quantum-electrodynamic and relativistic effects of atomic structure and offer new diagnostic techniques for hot low electron density plasmas.

References

[1] H.A. Sakaue et al, Phys. Rev. 100, 052515 (2019)

[2] Yu. Ralchenko, Y. Maron, JQSRT 71, 609 (2001)

[3] M.F. Gu, Can. J. Phys. 86, 675 (2008)

*Funded by NIST #70NANB19H024 and NSF #1806494

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Publication: "Analysis of E3 Transitions in Ag-like High-Z Ions Observed with the NIST EBIT", E. Takacs, Dipti, D. La Mantia, Submitted to Atoms, 2022

Presenters

  • Endre Takacs

    • Clemson University

Authors

  • Endre Takacs

    • Clemson University

  • FNU Dipti

    • International Atomic Energy Agency
    • National Institute of Standards and Technology, Gaithersburg, MD, 208995
    • National Institute of Standards and Technology

  • David S La Mantia

    • National Institute of Standards and Technology, Gaithersburg, MD, 208995
    • Clemson University
    • National Institute of Standards and Technology

  • Yang Yang

    • Clemson University

  • Aung Naing

    • University of Delaware
    • National Institute of Standards and Technology, Gaithersburg, MD, 208995

  • Paul Szypryt

    • National Institute of Standards and Technology
    • National Institute of Standards and Technology, Boulder, CO, 80303

  • Adam T Hosier

    • Clemson University

  • Joseph Tan

    • National Institute of Standards & Technology

  • Yuri Ralchenko

    • National Institute of Standards and Technology