Atomic data from the IRON Project. XLI. Electron excitation rates among the 3d2 fine-structure levels of Ca-like Fe VII
Abstract
Electron excitation collision strengths of 3d2 fine-structure transitions in Ca-like Fe vii are calculated using an R-matrix method, which included the 80 terms arising from the 3d2, 3d4s, 3d4p, 3d4d, 3d4f and 3p53d3 configurations. Extensive autoionizing resonance structures together with channel coupling is therefore explicitly included; relativistic effects are accounted for by a term-coupling transformation. A thermal average is taken to obtain the effective fine-structure collision strength as a function of electron temperature T, for log T(K) = 4.3-6. Open 3p-shell resonances are seen to considerably enhance the background collision strength, by several factors for some of the 3d2_{j-> j'} transitions.
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- March 2000
- DOI:
- 10.1051/aas:2000152
- Bibcode:
- 2000A&AS..142..313B
- Keywords:
-
- ATOMIC DATA