New detection systems for an enhanced sensitivity in key stellar (n,\(\gamma\)) measurements

• Published in: arXiv.org 2023-03
• Main Authors: Lerendegui-Marco, J, Babiano-Suárez, V, Balibrea-Correa, J, Domingo-Pardo, C, Ladarescu, I, Tarifeño-Saldivia, A, Alcayne, V, Cano-Ott, D, González-Romero, E, Martínez, T, Mendoza, E, Guerrero, C, Calviño, F, Casanovas, A, Köster, U, Chiera, N M, Dressler, R, Maugeri, E A, Schumann, D, the n_TOF Collaboration
• Format: Article
• Language: English
• Subjects: Absorption cross sections; Imaging techniques; Massive stars; Neutron scattering; Neutrons; Nuclear capture; Nuclear fusion; Nuclei; Red giant stars; Sensitivity enhancement; Thermal neutrons
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2303.08701

Neutron capture cross-section measurements are fundamental in the study of astrophysical phenomena, such as the slow neutron capture (s-) process of nucleosynthesis operating in red-giant and massive stars. However, neutron capture measurements via the time-of-flight (TOF) technique on key \(s\)-process nuclei are often challenging. Difficulties arise from the limited mass (\(\sim\)mg) available and the high sample-related background in the case of the unstable \(s\)-process branching points. Measurements on neutron magic nuclei, that act as \(s\)-process bottlenecks, are affected by low (n,\(\gamma\)) cross sections and a dominant neutron scattering background. Overcoming these experimental challenges requires the combination of facilities with high instantaneous flux, such as n\_TOF-EAR2, with detection systems with an enhanced detection sensitivity and high counting rate capabilities. This contribution reviews some of the latest detector developments in detection systems for (n,\(\gamma\)) measurements at n\_TOF, such as i-TED, an innovative detection system which exploits the Compton imaging technique to reduce the dominant neutron scattering background and s-TED, a highly segmented total energy detector intended for high flux facilities. The discussion will be illustrated with results of the first measurement of key the \(s\)-process branching-point reaction \(^{79}\)Se(n,\(\gamma\)).