Electron-ion recombination of Fe12+ forming Fe11+ : laboratory measurements and theoretical calculations

Hahn, M. and Badnell, N. R. and Grieser, M. and Krantz, C. and Lestinsky, M. and Müller, A. and Novotný, O. and Repnow, R. and Schippers, S. and Wolf, A. (2014) Electron-ion recombination of Fe12+ forming Fe11+ : laboratory measurements and theoretical calculations. Astrophysical Journal, 788 (1). ISSN 0004-637X

[img]
Preview
Text (Hahn-etal-AJ-2014-Electron-ion-recombination-of-Fe)
Hahn_etal_AJ_2014_Electron_ion_recombination_of_Fe.pdf
Accepted Author Manuscript

Download (1MB)| Preview

    Abstract

    We have measured dielectronic recombination (DR) for Fe12 + forming Fe11 + using the heavy ion storage ring TSR located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. Using our results, we have calculated a plasma rate coefficient from these data that can be used for modeling astrophysical and laboratory plasmas. For the low temperatures characteristic of photoionized plasmas, the experimentally derived rate coefficient is orders of magnitude larger than the previously recommended atomic data. The existing atomic data were also about 40% smaller than our measurements at temperatures relevant for collisionally ionized plasmas. Recent state-of-the-art theory has difficulty reproducing the detailed energy dependence of the DR spectrum. However, for the Maxwellian plasma rate coefficient, recent theoretical results agree with our measurements to within about 30% for both photoionized and collisionally ionized plasmas.