Eur. Phys. J. D (2013) 67: 223
https://doi.org/10.1140/epjd/e2013-40326-8

Regular Article

State selective photo-recombination cross sections in Be-like C and Al ions

National Institute for Laser, Plasma and Radiation Physics, Department of Lasers, Atomistilor 409, P.O. Box MG-36, 077125 Magurele-Ilfov, Romania

^a e-mail: viorica.stancalie@inflpr.ro

Received: 29 May 2013
Received in final form: 24 July 2013
Published online: 1 November 2013

Abstract

We report results from detailed state selective photo-recombination study along with the doubly excited autoionizing resonances in Be-like C²⁺ and Al⁹⁺ ions. In the present investigation, the primary focus is on detailed energy profiles of the individual photo-recombination cross sections. The calculation was carried out for the excited Rydberg states of type 1s²2sns(¹S^e) which interact with the odd-parity continua up to the C³⁺ and Al¹⁰⁺ 2p threshold limit. The numerical evaluation has been performed at a fine energy mesh across all the autoionizing Rydberg series of resonances 1s²2pns(¹P⁰) converging to Li-like ion 2p threshold. The method of calculation keeps the essential ingredients of the Feshbach projection operator approximation. The photo-ionization cross sections have been evaluated with and without relativistic effects included into the R-matrix numerical procedures, while the allowance for both quantum interference between dielectronic and radiative recombination, and overlapping resonances has been done utilizing results from the earlier R-matrix Floquet calculation. We discuss all these results with respect to the effect of quantum interference term on the energy dependence profile of photo-recombination cross section for studied transitions.