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arXiv · 2505.14833

Comprehensive Laboratory Benchmark of K-shell Dielectronic Satellites of Fe XXV-XXI Ions

Chintan Shah·Pedro Amaro·Filipe Grilo·Ming Feng Gu·Liyi Gu·José Paulo Santos·F. Scott Porter·Thomas Pfeifer·Maurice A. Leutenegger·José R. Crespo López-Urrutia
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Abstract

We report on comprehensive laboratory studies of the K-shell dielectronic recombination (DR) resonances of Fe XXV - XXI ions that prominently contribute to the hard X-ray spectrum of hot astrophysical plasmas. By scanning a monoenergetic electron beam to resonantly excite trapped Fe ions in an electron beam ion trap, and achieving a high electron-ion collision energy resolution of ~7 eV, we resolve their respective KL$n$ satellites up to n'=11. By normalization to known radiative recombination cross sections we also determine their excitation cross sections and that of the continuum with uncertainties below 15%, and verify our results with an independent normalization based on previous measurements. Our experimental data excellently confirm the accuracy and suitability of distorted-wave calculations obtained with the Flexible Atomic Code (FAC) for modeling astrophysical and fusion plasmas.

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Chintan Shah, Pedro Amaro, Filipe Grilo, Ming Feng Gu, Liyi Gu, José Paulo Santos, F. Scott Porter, Thomas Pfeifer, Maurice A. Leutenegger, José R. Crespo López-Urrutia. 2025-05-20. Comprehensive Laboratory Benchmark of K-shell Dielectronic Satellites of Fe XXV-XXI Ions. https://arxiv.org/abs/2505.14833

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