Astron. Astrophys. Suppl. Ser. 137, 165-173

Atomic data from the IRON Project

XXXVIII. Electron impact excitation of the fine-structure transitions in the n=3 complex of Fe xv

W. Eissner¹ - M.E. Galavís^2,4 - C. Mendoza^3,4 - C.J. Zeippen⁴

Send offprint request: C.J. Zeippen

1 - Fakultät für Physik und Astronomie, Ruhr-Universität, D-44780 Bochum, Germany
2 - Departamento de Física, Universidad Metropolitana, PO Box 76819, Caracas 1070A, Venezuela
3 - Centro de Física, Instituto Venezolano de Investigaciones Científicas (IVIC), PO Box 21827, Caracas 1020A, Venezuela
4 - UMR 8631 (associée au CNRS et à l'Université Paris 7) et DAEC, Observatoire de Paris, F-92195 Meudon, France

Received December 10, 1998; accepted March 2, 1999

Abstract:

As part of a systematic study of the collisional properties of Fe ions carried out by the IRON Project, electron excitation rates (effective collision strengths) are computed for all the fine-structure transitions within the n=3 complex of Fe XV in the electron temperature range $10^5\leq T/K\leq 10^7$.Configuration-interaction target wavefunctions are generated with the atomic structure code SUPERSTRUCTURE, and collision strengths are computed in the close-coupling approximation with a Breit-Pauli R-matrix package. Special care is taken to resolve the resonance structure and to ensure the convergence of the partial wave expansion, specially for dipole allowed transitions. By comparing with previously calculated collision strengths in the distorted wave approximation, a 20% accuracy rating is assigned to transitions with effective collision strengths $\Upsilon(T)\gt 10^{-2}$.

Key words: atomic data -- Sun: corona