Dielectronic Recombination of Fe XIX Forming Fe XVIII: Laboratory Measurements and Theoretical Calculations

摘要: We have measured resonance strengths and energies for dielectronic recombination (DR) of Fe XIX forming XVIII via N = 2 → N' 3 core excitations. All measurements were carried out using the heavy-ion Test Storage Ring at Max Planck Institute Nuclear Physics in Heidelberg, Germany. also calculated these two independent, state-of-the-art techniques: perturbative multiconfiguration Breit-Pauli (MCBP) Dirac-Fock (MCDF) methods. Overall, reasonable agreement is found between our experimental results theoretical calculations. The most notable discrepancies are 3l3l' resonances. MCBP MCDF n complex lie, respectively, ≈47% ≈31% above values. These larger than estimated 20% total uncertainty measurements. used to produce a Maxwellian-averaged rate coefficient DR XIX. Our experimentally derived be good better ≈20% kBTe ≥ 1 eV. predicted form photoionized collisionally ionized cosmic plasmas Hence, suitable use ionization balance calculations plasmas. Previously published coefficients poor with results. None reliably reproduce magnitude or temperature dependence coefficient. agree within ≈20%.