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Astron. Astrophys. Suppl. Ser. 142, 317-323

Electron-impact excitation of Fe7+

D.C. Griffin1 - M.S. Pindzola2 - N.R. Badnell3

Send offprint request: D.C. Griffin

1 - Department of Physics, Rollins College, Winter Park, FL 32789, U.S.A.
2 - Department of Physics, Auburn University, Auburn, AL 36849, U.S.A.
3 - Department of Physics and Applied Physics, University of Strathclyde, Glasgow G4 ONG, UK

Received September 20; accepted December 22, 1999


Electron-impact excitation cross sections for Fe7+ are calculated using R-matrix close-coupling theory. The calculation includes 33 LS terms of the seven configurations: 3p63d, 3p53d2, 3p53d4s, 3p64s, 3p64p, 3p64d, and 3p64f. Following an intermediate-coupling frame transformation of the LS K-matrices, cross sections and effective collision strengths are obtained for 2926 transitions among 77 LSJ levels of the original seven configurations. After the solution of the corresponding collisional-radiative equations, the emission line ratio involving a blend of the 3p64f 2F $\rightarrow $ 3p63d 2D transitions at around 131 A and another blend of the 3p53d2 2P $\rightarrow $ 3p63d 2D and 3p53d2 2D $\rightarrow $ 3p63d 2D transitions at around 168 A is found to provide a very useful electron-temperature diagnostic.

Key words: atomic data -- Sun: corona

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