Balibrea Correa, J.Mendoza, E.Cano-Ott, D.González, E.Capote, R.Krticka, M.Cortés Giraldo, Miguel AntonioLerendegui Marco, JorgePraena Rodríguez, JavierQuesada Molina, José ManuelSabaté Gilarte, MartaŽugec, P.2022-02-142022-02-142020Balibrea Correa, J., Mendoza, E., Cano Ott, D., González, E., Capote, R., Krticka, M.,...,Žugec, P. (2020). Measurement of the α ratio and (n, γ) cross section of 235U from 0.2 to 200 eV at n_TOF. Physical Review C, 102, 044615.2469-99852469-9993https://hdl.handle.net/11441/129944We measured the neutron capture-to-fission cross-section ratio (α ratio) and the capture cross section of 235U between 0.2 and 200 eV at the n_TOF facility at CERN. The simultaneous measurement of neutron-induced capture and fission rates was performed by means of the n_TOF BaF2 Total Absorption Calorimeter (TAC), used for detection of γ rays, in combination with a set of micromegas detectors used as fission tagging detectors. The energy dependence of the capture cross section was obtained with help of the 6 Li(n,t) standard reaction determining the n_TOF neutron fluence; the well-known integral of the 235U(n, f ) cross section between 7.8 and 11 eV was then used for its absolute normalization. The α ratio, obtained with slightly higher statistical fluctuations, was determined directly, without need for any reference cross section. To perform the analysis of this measurement we developed a new methodology to correct the experimentally observed effect that the probabilities of detecting a fission reaction in the TAC and the micromegas detectors are not independent. The results of this work have been used in a new evaluation of 235U performed within the scope of the Collaborative International Evaluated Library Organisation (CIELO) Project, and are consistent with the ENDF/B-VIII.0 and JEFF-3.3 capture cross sections below 4 eV and above 100 eV. However, the measured capture cross section is on average 10% larger between 4 and 100 eV.application/pdf18 p.engAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccesshttps://doi.org/10.1103/PhysRevC.102.044615