Atomic data and spectral line intensities for Ne-like Fe XVII

Electron impact collision strengths and spontaneous radiative decay rates are calculated for the Ne-like ion Fe XVII. The data pertain to the 37 levels of the configurations 2s[sup 2]2p[sup 6], 2s[sup 2]2p[sup 5]3s, 2s[sup 2]2p[sup 5]3p, 2s[sup 2]2p[sup 5]3d, 2s2[sup 6]3s, 2s2p[sup 6]3p, and 2s2p[sup 6]3d. Collision strengths are calculated at five energies. In Rydberg units these energies are 76.83, 91.53, 120.93, 179.73, and 253.23. Spectral line intensities are calculated for all transitions with intensities within two orders of magnitude of the most intense line in each ion. These are obtained by computing the excitation rate coefficients (cm[sup 3] s[sup [minus]1]), that is, the collision strengths integrated over a Maxwellian electron distribution, and then solving the equations of detailed balance for the populations of the 37 energy levels, assuming a collisional excitation model. The level populations are computed for several electron densities and are also given in this paper. 17 refs., 4 tabs.

[1]  A. Burgess,et al.  Electron impact excitation of the resonance lines of alkali-like positive ions , 1974 .

[2]  M. Rosen,et al.  Theory and design of soft x-ray laser experiments at the Lawrence Livermore National Laboratory , 1989 .

[3]  J. Hunter,et al.  Exact solutions for a generalized Mestel disc, and for truncated Toomre discs , 1984 .

[4]  H. L. Zhang,et al.  Relativistic Distorted Wave Collision Strengths for Excitation to the 88 n = 3 and n = 4 Levels in All 71 Neon-like Ions with 22 <= Z <= 92 , 1989 .

[5]  Honglin Zhang,et al.  Collision Strengths and Oscillator Strengths for Excitation to the n=3 and 4 Levels of Neon-like Ions , 1987 .

[6]  W. Eissner,et al.  Techniques for the calculation of atomic structures and radiative data including relativistic corrections , 1974 .

[7]  D. Mckenzie,et al.  X-Ray Line Ratios for Fe XVII Observed in the Solar Corona. , 1985 .

[8]  U. Litzén,et al.  The 2p53s, 3p and 3d Configurations in Neon-Like Ti XIII and Fe XVII , 1984 .

[9]  J. B. Mann.  Excitation collision strengths for iron ions calculated with a distorted wave method , 1983 .

[10]  McLean,et al.  Soft x-ray lasing in neonlike germanium and copper plasmas. , 1987, Physical review letters.

[11]  M. Seaton,et al.  Computer programs for the calculation of electron-atom collision cross sections. I. General formulation , 1972 .

[12]  U. Feldman,et al.  New identifications of Fe XVII spectral lines in solar flares , 1985 .

[13]  C. Jupén.  Identifications of Fe XVII and Ni XIX in solar flares based on isoelectronic extrapolations , 1984 .

[14]  P. L. Hagelstein,et al.  Relativistic distorted-wave calculations of electron collision cross sections and rate coefficients for Ne-like ions , 1987 .