Atomic data and spectral line intensities for n=3-3 and n=3-4 x-ray transitions in Fe XV

Transition rates, oscillator strengths, and collision strengths between the fine-structure levels of Fe XV have been calculated using the configurations 3s(2), 3s3p, 3p(2), 3s3d, 3p3d, 3s4s, 3s4p, 3s4d, 3s4f, 3p4s, 3p4p, 3p4d, and 3p4f. The calculations were carried out using the Superstructure and distorted wave programs developed at University College, London, together with a new program, NELMA (no-exchange Limeil-Meudon approximation). Level populations and relative spectral line intensities are calculated for four temperatures with log T-e(K) in the range 6.2 to 6.8 and for electron densities N-e = 10(8)-10(12) cm(-3). These data have been used to investigate the rocket spectrum of a solar flare in the 10-100 Angstrom range. The strong unidentified spectral line at 69.65 Angstrom has been attributed to the transition 3s3p P-1(1)-3s4s S-1(0). (C) 1997 Academic Press.