TY - JOUR
T1 - Dielectronic recombination of Fe XXIII forming Fe XXII
T2 - Laboratory measurements and theoretical calculations
AU - Savin, D.W.
AU - Gwinner, G.
AU - Grieser, M.
AU - Repnow, R.
AU - Schnell, M.
AU - Schwalm, D.
AU - Wolf, A.
AU - Zhou, S.G.
AU - Kieslich, S.
AU - Muller, A.
AU - Schippers, S.
AU - Colgan, J.
AU - Loch, S.D.
AU - Badnell, N.R.
AU - Chen, M.H.
AU - Gu, M.F.
PY - 2006/5/10
Y1 - 2006/5/10
N2 - We have measured resonance strengths and energies for dielectronic recombination (DR) of beryllium-like Fe XXIII forming boron-like Fe XXII via N = 2 -> N' = 2 and N = 2 -> N' = 3 core excitations. All measurements were carried out using the heavy-ion Test Storage Ring at the Max Planck Institute for Nuclear Physics (MPI-K) in Heidelberg, Germany. We have also calculated these resonance strengths and energies using three independent, perturbative, state-of-the-art theoretical techniques: the multiconfiguration Breit-Pauli (MCBP) method, the multiconfiguration Dirac-Fock (MCDF) method, and the Flexible Atomic Code (FAC). Overall reasonable agreement is found between our experimental results and these theoretical calculations. We have used our measurements to produce a Maxwellian-averaged DR rate coefficient for Fe XXIII. Our experimentally derived rate coefficient is estimated to be accurate to better that approximate to 20%. At temperatures where Fe XXIII is predicted to form in both photo-ionized and electron-ionized gas, we find mixed agreement between our experimental rate coefficient and previously published rate coefficients. We find good agreement at these temperatures between the experimentally derived rate coefficient and our MCBP, MCDF, and FAC results.
AB - We have measured resonance strengths and energies for dielectronic recombination (DR) of beryllium-like Fe XXIII forming boron-like Fe XXII via N = 2 -> N' = 2 and N = 2 -> N' = 3 core excitations. All measurements were carried out using the heavy-ion Test Storage Ring at the Max Planck Institute for Nuclear Physics (MPI-K) in Heidelberg, Germany. We have also calculated these resonance strengths and energies using three independent, perturbative, state-of-the-art theoretical techniques: the multiconfiguration Breit-Pauli (MCBP) method, the multiconfiguration Dirac-Fock (MCDF) method, and the Flexible Atomic Code (FAC). Overall reasonable agreement is found between our experimental results and these theoretical calculations. We have used our measurements to produce a Maxwellian-averaged DR rate coefficient for Fe XXIII. Our experimentally derived rate coefficient is estimated to be accurate to better that approximate to 20%. At temperatures where Fe XXIII is predicted to form in both photo-ionized and electron-ionized gas, we find mixed agreement between our experimental rate coefficient and previously published rate coefficients. We find good agreement at these temperatures between the experimentally derived rate coefficient and our MCBP, MCDF, and FAC results.
KW - atomic data
KW - atomic processes
KW - finite density plasmas
KW - electron ion recombination
KW - high resolution measurement
KW - rate coefficients
KW - ionization equilibrium
KW - isoelectronic sequences
KW - BE-like
KW - radiative recombination
KW - core excitations
KW - storage ring
U2 - 10.1086/501420
DO - 10.1086/501420
M3 - Article
VL - 642
SP - 1275
EP - 1285
JO - The Astrophysical Journal
JF - The Astrophysical Journal
SN - 0004-637X
IS - 2
ER -