Polarization studies on the dielectronic recombination hypersatellite x-ray lines

Abstract

The dielectronic recombination of heavy ions has been studied theoretically within the framework of the density matrix theory and the multiconfiguration Dirac-Fock approach. Emphasis was placed especially on the (linear) polarization of the characteristic x-ray emission and how it is affected by the non-dipole terms in the expansion of the electron-photon interaction operators. In particular, it is found that the interference between the leading electric-dipole (E1) and higher-electric and magnetic-multipole channels may significantly enhance the degree of linear polarization of the Kα hypersatellite lines. Detailed calculations for such a multipole-mixing effect are performed for the decay of the doubly-excited L3/2L3/2 resonances following the dielectronic recombination of (initially) hydrogen-like uranium U91+ ions. © 2010 IOP Publishing Ltd.