Measurement of differential and total cross sections for scattering of 14.1 MeV neutrons on \(^{12}\)C nuclei

Abstract

Differential cross sections of the elastic and inelastic scattering of 14.1 MeV neutrons on \(^{12}\)C for \(^{12}\)C(n,n\(_{0,1-4,7}\))\(^{12}\)C channels were measured in the framework of the TANGRA project. The experiment was carried out using the tagged neutron method which helped to reduce the background of random coincidences, determine the neutron flux on the target, and determine the energy of scattered neutrons by the time-of-fligh. The total reaction cross sections were calculated by approximating the measured differential cross sections by expansions in Legendre polynomials and then integrating over the entire range of solid angles. The measured values of the differential cross sections are generally in agreement with the experimental data of other authors within the measurement uncertainties. The obtained data for the total partial cross sections for elastic scattering are in agreement within uncertainties with the evaluated data from various nuclear data libraries (ENDF/B-VIII.0, EAF-2010, FENDL-3.1, JEFF-3.3, JENDL-4.0/HE). The cross section for \(^{12}\)C(n,n\(_1\))\(^{12}\)C channel is in agreement with the data from FENDL-3.1 and JENDL-4.0/HE. The total experimental cross section for the \(^{12}\)C(n,n\(_{2-7}\))\(^{12}\)C channels, which lead to the decay of the \(^{12}\)C nucleus into 3\(\alpha \)-particles obtained in the present work in combination with the experimental data of other authors are consistent with similar cross sections evaluated from the ENDF/B-VIII.0 and JEFF-3.3 libraries, but is significantly smaller than the one estimated from the EAF-2010 library. This result may indicate the need to reduce the evaluations of helium production in carbon compounds under the operating conditions of a fusion reactor, previously made based on the EAF library.