Astron. Astrophys. Suppl. Ser. 131, 499-522

Atomic data from the IRON Project

XXIX. Radiative rates for transitions within the n = 2 complex in ions of the boron isoelectronic sequence

M.E. Galavís^1,2,3 - C. Mendoza^2,3 - C.J. Zeippen³

Send offprint request: C.J. Zeippen

1 - Departamento de Física, Universidad Metropolitana, PO Box 76819, Caracas 1070A, Venezuela
2 - Centro de Física, Instituto Venezolano de Investigaciones Científicas (IVIC), PO Box 21827, Caracas 1020A, Venezuela
3 - URA 173 (associée au CNRS et à l'Université Paris 7) et DAEC, Observatoire de Paris, F-92195 Meudon, France

Received December 30, 1997; accepted March 18, 1998

Abstract:

As part of the IRON Project, radiative rates have been calculated for the E1, E2 and M1 transitions within the n=2 complex in ions of the boron isoelectronic sequence ($6\le Z\le 28$). The computations have been carried out with the atomic structure code SUPERSTRUCTURE which facilitates the generation of extended radiative datasets including configuration interaction, Breit-Pauli relativistic contributions and semi-empirical term-energy corrections. By means of extensive comparisons with the available datasets for this sequence, with detailed single-ion calculations and recent experiments, we have been able to assign accuracy ratings to the present A-values. We find that in general the spin-allowed and spin-forbidden E1 transitions are accurate to 10% and 20%, respectively, except for a few transitions in ions with $Z\le 7$ that are perturbed by admixture with low-lying n=3 states (e.g. 2s$\sp23l$)and for those affected by the avoided crossing of the 2s2p$\sp2\ \sp2$S_1/2 and $\sp2$P_1/2 which takes place at $Z\sim 22$. It is concluded that, statistically, the present dataset is the most accurate to date for this astrophysically relevant sequence.

Key words: atomic data -- atomic processes