Electron impact excitation rates among the 3d fine-structure levels
of Ca-like Fe sc vii |

K.A. Berrington, S. Nakazaki, and P.H. Norrington |

Astronomy & Astrophysics Supplement Series, 2000, Vol.142, pp.313-316 |

Electron excitation collision strengths of 3d fine-structure transitions
in Ca-like Fe sc vii are calculated using an R-matrix method, which
included the 80 terms arising form the 3d, 3d4s, 3d4p, 3d4d, 3d4f and
3p3d 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 (K)-6. Open 3p-shell resonances are seen to considerably enhance
the background collision strength, by several factors for some of the
3d
transitions.

2006-10-25