Atomic data from the IRON project. LXVIII. Electron impact excitation of Fe xi
Abstract
A new R-matrix scattering calculation for electron collisional excitation of Fe xi is presented and compared to earlier calculations. The calculation includes 145 LS terms and 465 fine-structure levels and uses the intermediate-coupling frame transformation method (ICFT). We discuss the strong interactions that exist between three J = 1 levels in the 3s2 3p3 3d electron configuration. These levels give rise to strong lines in the EUV spectrum and their energies and identifications have been the source of much confusion in the literature. We show that the oscillator and collision strengths linking these levels to the ground levels of the ion are very sensitive to the choice of configuration basis and argue that most earlier calculations have failed to represent these levels adequately.
Detailed tables of the present data are available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/514/A40- Publication:
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Astronomy and Astrophysics
- Pub Date:
- May 2010
- DOI:
- 10.1051/0004-6361/200913006
- Bibcode:
- 2010A&A...514A..40D
- Keywords:
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- atomic data;
- line: identification;
- techniques: spectroscopic