Measurement of (alpha,n) reaction cross sections of erbium isotopes for testing astrophysical rate predictions

Abstract

The $\gamma$-process in core-collapse and/or type Ia supernova explosions is thought to explain the origin of the majority of the so-called $p$ nuclei (the 35 proton-rich isotopes between Se and Hg). Reaction rates for $\gamma$-process reaction network studies have to be predicted using Hauser-Feshbach statistical model calculations. Recent investigations have shown problems in the prediction of $\alpha$-widths at astrophysical energies which are an essential input for the statistical model. It has an impact on the reliability of abundance predictions in the upper mass range of the $p$ nuclei. With the measurement of the ${}^{164,166}$Er($\alpha$,n)${}^{167,169}$Yb reaction cross sections at energies close to the astrophysically relevant energy range we tested the recently suggested low energy modification of the $\alpha$+nucleus optical potential in a mass region where $\gamma$-process calculations exhibit an underproduction of the $p$ nuclei. Using the same optical potential for the $\alpha$-width which was derived from combined ${}^{162}$Er($\alpha$,n) and ${}^{162}$Er($\alpha$,$\gamma$) measurement makes it plausible that a low-energy modification of the optical $\alpha$+nucleus potential is needed.

References in corpus (6)

• Photon-induced Nucleosynthesis: Current Problems and Experimental Approaches
• Alpha induced reaction cross section measurements on 162Er for the astrophysical gamma process
• Challenges in nucleosynthesis of trans-iron elements
• Experimental cross sections of 165Ho(α,n)168Tm and 166Er(α,n)169Yb for optical potential studies relevant for the astrophysical γ-process
• Astrophysical analysis of the measurement of (alpha,gamma) and (alpha,n) cross sections of 169Tm
• KADoNiS-$p$: The astrophysical $p$-process database

Cited by in corpus (8)

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• Cross section of $\alpha$-induced reactions on iridium isotopes obtained from thick target yield measurement for the astrophysical $\gamma$ process
• Analysis of uncertainties in alpha-particle optical-potential assessment below the Coulomb barrier
• Experimental study of the astrophysical gamma-process reaction 124Xe(alpha,gamma)128Ba
• Experimental techniques to study the $\gamma$ process for nuclear astrophysics at the Cologne accelerator laboratory