PHOTOIONIZATION CROSS-SECTIONS FOR FE-XVII

This paper reports the first close-coupling photoionisation calculatio n of Fe XVII, and provides accurate total and partial cross sections f or photon energies up to 450 Ryd. The total and first partial photoion isation cross sections, the latter obtained when the Fe XVIII ion is l eft in the 2s(2)2p(5) (2)p(o) ground state, are dominated by resonance structure for photon energies in the range from threshold to excitati on of the first excited state (2s2p(6 2)S) of Fe XVIII. This is the fi rst time that such structure has been determined. The background cross section is found to be in good agreement (to within 10%) with the res ults of Verner and co-workers for the total cross section, and for the partial cross sections corresponding to 2p and 2s photoejection, resp ectively.