ATOMIC DATA FROM THE IRON PROJECT .21. ELECTRON-EXCITATION OF FINE-STRUCTURE TRANSITIONS INVOLVING THE 3D(6)4S(2) D-5 GROUND-STATE AND THE 3D(7)4S F5 METASTABLE STATE OF FE-I

Low energy electron excitation collision strengths for fine-structure transitions involving the 3d(6)4s(2 5)D(J) ground term and the 3d(7)4s F-5(J) first excited term of neutral Fe are calculated. The model tar get atom includes the lowest three terms (D-5, 5F and 3F) together wit h four pseudostates (<(P-5(o))over bar>, <(D-5(o))over bar>, <(F-5(o)) over bar>, <((5)G(o))over bar>) chosen to represent the dipole polariz ability of the ground term and first excited term of Fe. The Breit-Pau li R-matrix method is used to calculate the fine-structure collision s trength, which is averaged over a Maxwellian velocity distribution to obtain effective collision strengths as a function of electron tempera ture in the range 100 - 4000 K. The low-temperature form of the collis ion strength is established for the first time for Fe I.