Dielectronic recombination of Cu-like W45+

Abstract

We have investigated dielectronic recombination (DR) for Cu-like W45+ forming Zn-like W44+ by theoretical calculation using the flexible atomic code based on an independent process, isolated resonance, and distorted wave approximation. We have focused on the effect of configuration mixing involving double electron core excitation as well as single electron core excitation on the DR via 3d94l4l′4l″ and 3p53d104l4l′4l″ resonances by inner-shell core excitation Δnc=1. About 20% and over 100% changes in Maxwellian rate coefficient are shown at high energies over 200eV and at low energies near the threshold, respectively, by the configuration mixing. Non-resonant stabilizations (NRS) and decays to autoionizing levels possibly followed by cascades (DAC) to non-closed inner-shells 3d94l4l′4l″ are also considered. The NRS and DAC effect on the DR Maxwellian rate coefficient is relatively smaller than the configuration mixing effect and is less than ~20%. Particular attention has been paid to the DR via 3d104lnl′ resonances by valence-shell core excitation Δnc=0 which was not considered in the previous work (Behar et al., 1997 [4]). The 3d104lnl′ resonances very dominate the DR at low energies below ~100eV. Δnc=2 core excitations are small but not negligible (~10%) relatively at high energy range around 10keV. Our total DR rate coefficient shows the difference with the recombination coefficient on the ADAS database obtained by using a simple semiempirical formula over order of magnitude at low energies and about 30–50% at 2–7keV energy range where W45+ is abundant.