Electron impact excitation collision strengths and rate coefficients
for Fe IV |

H.L. Zhang and A.K. Pradhan |

Astronomy & Astrophysics Supplement Series, 1997, Vol.126, pp.373-378 |

Collision strengths and maxwellian-averaged rate coefficients have been
calculated for 8771 non-vanishing transitions among 140 fine structure
levels, dominated by the configurations 3d, 3d4s and 3d4p in
Fe IV. Collision strengths are calculated using the *R*-matrix
method with a 49 term close-coupling target expansion for electron energies
up to 15 rydbergs. Rate coefficients are tabulated for a wide range of
temperatures in which Fe IV is abundant in plasma sources. A brief
discussion of the calculations and sample results are given. The present
rates for Fe IV are expected to find applications in spectral
diagnostics of a variety of astrophysical sources.

2006-10-25