Astron. Astrophys. Suppl. Ser.
Volume 131, Number 1, July 1998
|Page(s)||153 - 166|
|Published online||15 July 1998|
Atomic data from the IRON project*
XXXI. Electron impact excitation of optically allowed and intercombination electric dipole transitions in Fe xii
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Silver Street, Cambridge CB3 9EW, UK
2 Department of Physics and Astronomy, University College London, Gower Street, London WC1 E6BT, UK
Send offprint request to: A. Binello
Accepted: 24 February 1998
A new, accurate set of electron impact collisional data is presented, relating to all electric dipole fine-structure transitions between the ground 3s2 3p3 and the first two excited 3s 3p4, 3s2 3p2 3d configurations in Fe xii (Fe11+). Theoretical energies have been obtained with a multi-configuration atomic structure calculation. The R-matrix method, coupled with the Coulomb-Bethe (CBe) approximation for the high partial wave contributions to the collision strengths, has been employed in the Fe11+ - scattering problem. The data presented in this paper form part of the IRON Project effort to provide the most accurate atomic data available to date for all the iron ions (Hummer et al. 1993).
Key words: ion / atomic data / atomic processes / Sun: UV radiation
Tables 1 to 9 are also available in electronic form at the CDS via ftp to cdsarc.u-strasbg.fr (220.127.116.11) or via http://cdsweb.u-strasbg.fr/Abstract.html
© European Southern Observatory (ESO), 1998