n_TOF Collaboration(Alcayne, V. et al), Caballero-Ontanaya, L., Domingo-Pardo, C., Ladarescu, I., & Tain, J. L. (2024). Measurement and analysis of the 246Cm and 248Cm neutron capture cross-sections at the EAR2 of the n_TOF facility at CERN. Eur. Phys. J. A, 60(12), 246–20pp.
Abstract: The 246Cm(n,γ) and 248Cm(n,γ) cross-sections have been measured at the Experimental Area 2 (EAR2) of the nTOF facility at CERN with three C6D6 detectors. This measurement is part of a collective effort to improve the capture cross-section data for Minor Actinides (MAs), which are required to estimate the production and transmutation rates of these isotopes in light water reactors and innovative reactor systems. In particular, the neutron capture in 246Cm and 248Cm open the path for the formation of other Cm isotopes and heavier elements such as Bk and Cf and the knowledge of (n,γ) cross-sections of these Cm isotopes plays an important role in the transport, transmutation and storage of the spent nuclear fuel. The reactions 246Cm(n,γ) and 248Cm(n,γ) have been the two first capture measurements analyzed at nTOF EAR2. Until this experiment and two recent measurements performed at J-PARC, there was only one set of data of the capture cross-sections of 246Cm and 248Cm, that was obtained in 1969 in an underground nuclear explosion experiment. In the measurement at n_TOF a total of 13 resonances of 246Cm between 4 and 400 eV and 5 of 248Cm between 7 and 100 eV have been identified and fitted. The radiative kernels obtained for 246Cm are compatible with JENDL-5, but some of them are not with JENDL-4, which has been adopted by JEFF-3.3 and ENDF/B-VIII.0. The radiative kernels obtained for the first three 248Cm resonances are compatible with JENDL-5, however, the other two are not compatible with any other evaluation and are 20% and 60% larger than JENDL-5.
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Bemmerer, D., Boeltzig, A., Grieger, M., Gudat, K., Hensel, T., Masha, E., et al. (2025). The Felsenkeller shallow-underground laboratory for nuclear astrophysics. Eur. Phys. J. A, 61(1), 19–15pp.
Abstract: In the Felsenkeller shallow-underground site, protected from cosmic muons by a 45 m thick rock overburden, a research laboratory including a 5 MV Pelletron ion accelerator and a number of radioactivity-measurement setups is located. The laboratory and its installations are described in detail. The background radiation has been studied, finding suppression factors of 40 for cosmic-ray muons, 200 for ambient neutrons, and 100 for the background in germanium gamma-ray detectors. Using an additional active muon veto, typically the background is just twice as high as in very deep underground laboratories. The properties of the accelerator including its external and internal ion sources and beam line are given. For the radioactivity counting setup, detection limits in the 10-4 Bq range have been obtained. Practical aspects for the usage of the laboratory by outside scientific users are discussed.
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Davesne, D., Navarro, J., Pastore, A., & Lallouet, Y. (2025). Isovector properties of effective finite-range nuclear interactions. Eur. Phys. J. A, 61(2), 28–23pp.
Abstract: We discuss several properties of two families of finite-range interactions in infinite nuclear matter, aiming in particular to their isovector properties. We find that the recent parameterisations of both Gogny and Nakada provide a reasonable description of the properties of the infinite medium as well as an equation of state capable of sustaining a two solar mass neutron star. We also discuss the pairing properties in the spin-singlet channel for both families of interactions.
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Li, H. P., Lin, J. X., Liang, W. H., & Oset, E. (2025). Determination of the K + (K)over-bar0 scattering length and effective range and its relation to the a0+ (980) from the χc1 → π+π-η reaction. Eur. Phys. J. A, 61(5), 97–8pp.
Abstract: We analyze the clean cusp, seen in the eta pi mass distribution with high precision of the chi(c1)->eta pi(+)pi(-) reaction in the BESIII experiment, with the aim of making a precise determination of the scattering length a and effective range r(0) of K+(K) over bar (0). For that, we follow a previous theoretical work that gave a good reproduction of these data using the chiral unitary approach for the meson-meson interaction, and allow some flexibility in the input to carry a better fit to the data. The important task of determining the uncertainties in the scattering parameters is done using the resampling method and an accuracy in a and r(0) is obtained better than 20%. The effective range is determined for the first time with this analysis.
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n_TOF Collaboration(Domingo-Pardo, C. et al), Balibrea-Correa, J., Gameiro, B., de la Fuente Rosales, G., Lerendegui-Marco, J., Tarifeño-Saldivia, A., et al. (2025). Neutron capture measurements for s-process nucleosynthesis. Eur. Phys. J. A, 61(5), 105–19pp.
Abstract: This article presents a review about the main CERN nTOF contributions to the field of neutron-capture experiments of interest for s-process nucleosynthesis studies over the last 25 years, with a special focus on the measurement of radioactive isotopes. A few recent capture experiments on stable isotopes of astrophysical interest are also discussed. Results on s-process branching nuclei are appropriate to illustrate how advances in detection systems and upgrades in the facility have enabled increasingly challenging experiments and, as a consequence, have led to a better understanding and modeling of the s-process mechanism of nucleosynthesis. New endeavors combining radioactive-ion beams from ISOLDE for the production of radioisotopically pure samples for activation experiments at the new NEAR facility at nTOF are briefly discussed. On the basis of these new exciting results, also current limitations of state-of-the-art TOF and activation techniques will be depicted, thereby showing the pressing need for further upgrades and enhancements on both facilities and detection systems. A brief account of the potential technique based on inverse kinematics for direct neutron-capture measurements is also presented.
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