Savin, D.W. and Behar, E. and Kahn, S.M. and Gwinner, G. and Saghiri, A.A. and Schmitt, M. and Grieser, M. and Repnow, R. and Schwalm, D. and Wolf, A. and Bartsch, T. and Müller, A. and Schippers, S. and Badnell, N.R. and Chen, M.H. and Gorczyca, T.W. (2002) Dielectronic recombination (via N = 2→N = 2 core excitations) and radiative recombination of Fe xx: Laboratory measurements and theoretical calculations. Astrophysical Journal, 138. pp. 337370. ISSN 0004637X

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Abstract
We have measured the resonance strengths and energies for dielectronic recombination (DR) of Fe XX forming Fe XIX via N = 2 → N′ = 2 (N = 0) core excitations. We have also calculated the DR resonance strengths and energies using AUTOSTRUCTURE, HULLAC, MCDF, and Rmatrix methods, four different stateoftheart theoretical techniques. On average the theoretical resonance strengths agree to within . 10% with experiment. The AUTOSTRUCTURE, MCDF and Rmatrix results are in better agreement with experiment than are the HULLAC results. However, in all cases the 1σ standard deviation for the ratios of the theoreticaltoexperimental resonance strengths is & 30% which is significantly larger than the estimated relative experimental uncertainty of . 10%. This suggests that similar errors exist in the calculated level populations and line emission spectrum of the recombined ion. We confirm that theoretical methods based on inversephotoionization calculations (e.g., undamped Rmatrix methods) will severely overestimate the strength of the DR process unless they include the effects of radiation damping. We also find that the coupling between the DR and radiative recombination (RR) channels is small.
Item type:  Article 

ID code:  5828 
Keywords:  atomic dat, atomic processes, astrophysics, plasmas, Plasma physics. Ionized gases, Astronomy and Astrophysics, Space and Planetary Science 
Subjects:  Science > Physics > Plasma physics. Ionized gases 
Department:  Faculty of Science > Physics 
Depositing user:  Strathprints Administrator 
Date Deposited:  11 Apr 2008 
Last modified:  12 Dec 2015 18:45 
Related URLs:  
URI:  http://strathprints.strath.ac.uk/id/eprint/5828 
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