Single-photon emission from simultaneous two-electron transitions in He-like ions

Abstract

The electric and magnetic dipole radiations due to a double-electron jump from the 1 S 0 state of He-like ions with an empty K shell are evaluated for 21 ions with 10 Z 92 using fully relativistic multiconfiguration Dirac-Fock wave functions in the active space approximation with the inclusion of a finite nuclear size, the Breit interaction, self-energy, and vacuum polarization. The contributions from correlation and higher-order corrections to the x-ray energies and rates are discussed in detail. The effects of biorthogonal and partially orthogonal spin orbitals of the initial and final states on the correlation sensitive radiative rates are analyzed. The accuracy of our computed data is judged by the uncertainties in the fine structure energy levels along with the agreement in the length and velocity forms of transition rates. The present results are compared with other available theoretical data.

Effects of electron correlation and the Breit interaction on one- and two-electron one-photon transitions in double K hole states of He-like ions (10 ≤ Z ≤ 47)*

“…The TEOP process was first predicted theoretically by Heisenberg in 1925 [21] and was observed by Wölfli et al in ion-atom collision experiments between Ni-Ni, Ni-Fe, Fe-Ni and Fe-Fe in 1975 [22]. Since then, TEOP transitions have been widely studied both theoretically and experimentally [23][24][25][26][27][28][29][30][31][32][33][34][35].…”

“…There have been many works related to the energy levels and transition properties of inner-shell hole states in the past several decades [25][26][27][28][29][30][31][32][33][34][35][36][37], but only a few studies have focused on He-like ions [28][29][30][31][32][33][34][35]. The He-like ion is a two-electron system with a simple structure and an electron correlation effect and is a good candidate with which to study the TEOP process.…”

“…After that, Natarajan conducted research on the orthogonality of the basis. The biorthog-onal and common basis sets give almost the same transition rates for light and medium heavy elements while the differences are substantial for heavy elements [31]. The contributions from correlation and higher-order corrections, consisting of Breit and QED effects, to the energies and transition rates were analyzed.…”

“…[22] Since then, TEOP transitions have been widely studied both theoretically and experimentally. [23][24][25][26][27][28][29][30][31][32][33][34][35] The TEOP process is forbidden in the independent particle approximation of an atom. Investigations of this process are helpful for explaining the electron correlation effects, relativistic effects, and quantum electro-dynamics (QED) effects on the energy level structure and radiative transitions of these exotic atoms.…”

“…For astrophysical and laboratory plasmas, some important diagnostics information regarding the composition, temperature, and density has also been provided by these basic atomic physics processes. [23,24] There have been many works related to the energy levels and transition properties of inner-shell hole states in the past several decades, [25][26][27][28][29][30][31][32][33][34][35][36][37] but only a few studies have focused on He-like ions. [28][29][30][31][32][33][34][35] The He-like ion is a two-electron system with simple structure and electron correlation effect and is a good candidate for the study of the TEOP process.…”