Atomic-number dependence of the magnetic-sublevel population in the autoionization state formed in dielectronic recombination

Abstract

The magnetic-sublevel population of the autoionization state formed in dielectronic recombination (DR) of highly charged heavy ions has been experimentally investigated by combining two types of measurements with an electron beam ion trap. The two different measurements are the differential x-ray measurement at 90 • with respect to the electron beam and the integral resonance-strength measurement. The alignment parameter, which denotes the magnetic-sublevel population distribution, has been obtained for the autoionization states [1s2s 2 2p 1/2 ] 1 formed in DR of Li-like Pr (atomic number Z = 59) and Ho (Z = 67). This work is a complement to our previous work [Phys. Rev. Lett. 108, 073002 (2012)] on Li-like Au (Z = 79). The experimental results are in reasonable agreement with theoretical predictions, and a strong Z-dependent tendency due to the Breit interaction has been confirmed.

Polarization of K-shell Dielectronic Recombination Satellite Lines of Fe xix–xxv and Its Application for Diagnostics of Anisotropies of Hot Plasmas

“…It includes magnetic interactions and the retardation in the exchange of a virtual photon between the electrons. While its effect on energy levels is considered as a modest correction, it significantly changes the DR cross sections and the polarization of DR X-rays for high-Z ions (Nakamura et al 2008;Fritzsche et al 2009;Hu et al 2014;Shah et al 2015;Nakamura 2016;Amaro et al 2017).…”

Calculation of differential cross section for dielectronic recombination with two-electron uranium

“…Experimental investigation of dielectronic recombination with two-and three-electron ions of Pr, Ho and Au is reported in [5]. In particular, dielectronic recombination strengths are measured and calculated.…”

Polarization measurement of dielectronic recombination transitions in highly charged krypton ions

“…This noticeable change in the population of the magnetic sublevels leads to a 13 % decrease in the degree of linear polarization of x rays produced by Li 1 resonance. Although, this represents a small contribution of the Breit interaction as compared to the previously measured contributions in heavy elements [22,38], this experiment is nonetheless sensitive enough to validate theoretical calculations including the Breit interaction, and to rule out by 2σ calculations that treat the electron-electron inter-action purely by the Coulomb force.…”