Indirect measurement of the $(n,\gamma {)}^{127}$Sb cross section

Abstract

Nuclei in the ${}^{135}$I region have been identified as being a possible bottleneck for the \textit{i} process. Here we present an indirect measurement for the Maxwellian-averaged cross section of ${}^{126}\text{Sb}(n,\gamma )$. The nuclear level density and the $\gamma$-ray strength function of ${}^{127}$Sb have been extracted from ${}^{124}$Sn$(\alpha ,p\gamma {)}^{127}$Sb data using the Oslo method. The level density in the low-excitation-energy region agrees well with known discrete levels, and the higher-excitation-energy region follows an exponential curve compatible with the constant-temperature model. The strength function between $E_{\gamma }\approx$ 1.5-8.0 MeV presents several features, such as an upbend and a possibly double-peaked pygmy-like structure. None of the theoretical models included in the nuclear reaction code TALYS seem to reproduce the experimental data. The Maxwellian-averaged cross section for the ${}^{126}$Sb$(n,\gamma {)}^{127}$Sb reaction has been experimentally constrained by using our level-density and strength-function data as input to TALYS. We observe a good agreement with the JINA REACLIB, TENDL, and BRUSLIB libraries, while the ENDF/B-VIII.0 library predicts a significantly higher rate than our results.

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Cited by in corpus (2)

• Nuclear level densities and $\gamma$-ray strength functions in ${}^{120,124}$Sn isotopes: impact of Porter-Thomas fluctuations
• Experimentally constrained ${}^{165,166}\text{Ho}(n,\gamma )$ rates and implications for the $s$ process