**Up:** Abstract

A&A Supplement series, Vol. 122, April I 1997, 177-180

Received June 19; accepted July 15, 1996

## Atomic data from the IRON Project

### XXI. Electron excitation of fine-structure transitions involving the
3d4sD ground state and the
3d4sF metastable state of Fe I

**J. Pelan - K.A. Berrington**

*Send offprint request: *J. Pelan

Department of Applied Mathematics & Theoretical Physics,
The Queen's University, Belfast, BT7 1NN, UK

### Abstract:

Low energy electron excitation collision strengths for
fine-structure transitions involving the
ground term and the first excited term of neutral Fe
are calculated.
The model target atom includes the lowest three terms
(, and ) together with four pseudostates
(, ,
, )
chosen to represent the dipole polarizability
of the ground term and first excited term of Fe.
The Breit-Pauli R-matrix method is used to calculate the fine-structure
collision strength,
which is averaged over a Maxwellian velocity distribution to
obtain effective collision strengths as a function of electron temperature
in the range .
The low-temperature form of the collision strength is established
for the first time for Fe I.

**keywords:** atomic data

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