Atomic data and spectral line intensities for Ni XVII
Abstract
Electron impact collision strengths, energy levels, oscillator strengths, and spontaneous radiative decay rates are calculated for Ni XVII. We include in the calculations the 23 lowest configurations, corresponding to 159 finestructure levels: 3 l3 l', 3 l4 l″, and 3s5 l‴, with l, l' = s, p, d, l″ = s, p, d, f, and l‴ = s, p, d. Collision strengths are calculated at five incident energies for all transitions at varying energies above the threshold of each transition. One additional energy, very close to the threshold of each transition, has also been included. Calculations have been carried out using the Flexible Atomic Code in the distorted wave approximation. Additional calculations have been performed with the University College London suite of codes for comparison. Excitation rate coefficients are calculated as a function of electron temperature by assuming a Maxwellian electron velocity distribution. Using the excitation rate coefficients and the radiative transition rates of the present work, statistical equilibrium equations for level populations are solved at electron densities covering the range of 10 ^{8}  10 ^{14} cm ^{3} and at an electron temperature of log T_{e}(K) = 6.5, corresponding to the maximum abundance of Ni XVII. Spectral line intensities are calculated, and their diagnostic relevance is discussed. This dataset will be made available in the next version of the CHIANTI database.
 Publication:

Atomic Data and Nuclear Data Tables
 Pub Date:
 May 2011
 DOI:
 10.1016/j.adt.2010.07.001
 Bibcode:
 2011ADNDT..97..189B