Radiative and inner-shell dielectronic recombination in a highly charged barium ion.

Abstract

The direct radiative recombination (RR) to n=3, 4, and 5 levels and the resonant dielectronic recombination (DR) cross section involving 2p\ensuremath{\rightarrow}3d excitation of Sc-like barium ${\mathrm{Ba}}^{35+}$ and Ti-like barium ${\mathrm{Ba}}^{34+}$ are calculated and compared with a recent electron beam ion trap experiment at the National Institute of Standards and Technology. Assuming a fractional population of ${\mathrm{Ba}}^{35+}$ in the trap of about 30%, we obtain good agreement between theory and experiment for the cross section ratio \ensuremath{\sigma}(DR)/\ensuremath{\sigma}(RR)(n=4), as well as for \ensuremath{\sigma}(RR)(n=5)/\ensuremath{\sigma}(RR)(n=4). The result confirms again that the simple angular momentum averaged procedure can be effective in treating DR for heavy open-shell ions when the energy resolution is not high. A large, broad peak below 2 keV in the x-ray spectrum is being theoretically examined. \textcopyright{} 1996 The American Physical Society.