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Title: Atomic data and spectral line intensities for Ca IX

Electron impact collision strengths, energy levels, oscillator strengths, and spontaneous radiative decay rates are calculated for Ca IX. We include in the calculations the 33 lowest configurations in the n=3,4, and 5 complexes, corresponding to 283 fine-structure levels in the 3l3l{sup ′}, 3l4l{sup ″}, and 3l5l{sup ‴} configurations, where l,l{sup ′}=s,p,d, l{sup ″}=s,p,d,f and l{sup ‴}=s,p,d,f,g. Collision strengths are calculated at five incident energies for all transitions: 5.8, 13.6, 24.2, 38.6, and 57.9 Ry above the threshold of each transition. An additional energy, very close to the transition threshold, has been added, whose value is between 0.0055 Ry and 0.23 Ry depending on the levels involved. Calculations have been carried out using the Flexible Atomic Code and the distorted wave approximation. 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 calculated in the present work, statistical equilibrium equations for level populations are solved at electron densities covering the range of 10{sup 8}–10{sup 14}  cm{sup −3} and at an electron temperature of logT{sub e}(K)=5.8, corresponding to the maximum abundance of Ca IX. Spectral line intensities are calculated, and their diagnostic relevance is discussed.
Authors:
 [1] ;  [2]
  1. Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)
  2. NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
Publication Date:
OSTI Identifier:
22439765
Resource Type:
Journal Article
Resource Relation:
Journal Name: Atomic Data and Nuclear Data Tables; Journal Volume: 100; Journal Issue: 6; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; APPROXIMATIONS; ATOMS; CALCIUM; CONFIGURATION; DISTORTED WAVE THEORY; ELECTRON COLLISIONS; ELECTRON DENSITY; ELECTRON TEMPERATURE; ELECTRONS; ENERGY LEVELS; EXCITATION; FINE STRUCTURE; OSCILLATOR STRENGTHS; RADIATIVE DECAY; SPECTROSCOPY