Measurement of the Ce 140 (n,γ) Cross Section at n_TOF and Its Astrophysical Implications for the Chemical Evolution of the Universe

Description

Ce140(n,γ) is a key reaction for slow neutron-capture (s-process) nucleosynthesis due to being a bottleneck in the reaction flow. For this reason, it was measured with high accuracy (uncertainty ≈5%) at the n_TOF facility, with an unprecedented combination of a high purity sample and low neutron-sensitivity detectors. The measured Maxwellian averaged cross section is up to 40% higher than previously accepted values. Stellar model calculations indicate a reduction around 20% of the s-process contribution to the Galactic cerium abundance and smaller sizeable differences for most of the heavier elements. No variations are found in the nucleosynthesis from massive stars.

Abstract

National Science Foundation AST 1613536, AST 1815403/1815767, AST 2205847, PHY 1430152

Abstract

European Union RFF M4C2 1.1 PRIN 2022

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