1. Measurement of $^{238}\mathrm{U}(n,{n}^{{'}}{\gamma}$) cross section data and their impact on reaction models
- Author
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Kerveno, M., Dupuis, M., Bacquias, A., Belloni, F., Bernard, D., Borcea, C., Boromiza, M., Capote, R., De Saint Jean, C., Dessagne, P., Drohé, J., Henning, G., Hilaire, S., Kawano, T., Leconte, P., Nankov, N., Negret, A., Nyman, M., Olacel, A., Plompen, A., Romain, P., Rouki, C., Rudolf, G., Stanoiu, M., Wynants, R., Département Recherches Subatomiques (DRS-IPHC), Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Détection et de Géophysique (CEA) (LDG), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), European Commission - Joint Research Centre [Geel] (JRC), Horia Hulubei National Institute for Physics and Nuclear Engineering, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Matière sous Conditions Extrêmes (LMCE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire d'Etudes de PHysique (LEPH), Service de Physique des Réacteurs et du Cycle (SPRC), Département Etude des Réacteurs (DER), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Département Etude des Réacteurs (DER), International Atomic Energy Agency [Vienna] (IAEA), Los Alamos National Laboratory (LANL), European Project: 34186,EFNUDAT, European Project: 211499,EC:FP7:Fission,FP7-Fission-2007,EUFRAT(2008), European Project: 249671,EC:FP7:Fission,FP7-Fission-2009,ANDES(2010), European Project: 605203,EC:FP7:Fission,FP7-Fission-2013,CHANDA(2013), European Project: 847552,SANDA, and European Project: 516487,NUDAME
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[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,Nuclear Experiment - Abstract
International audience; A better knowledge of ($n,xn$) reaction cross sections is important for both reaction modeling and energy applications. This article focuses on inelastic scattering of neutrons off $^{238}$U for which improvements are needed to better constrain evaluations and solve inconsistencies in nuclear power reactor calculations. A new precise measurement of ($n,xn\gamma$) reaction cross sections on $^{238}$U has been performed at the GELINA (Geel Electron LINear Accelerator) neutron facility operated by EC-JRC-Geel (Belgium) with the GRAPhEME (GeRmanium array for Actinides PrEcise MEasurements) setup. The prompt $\gamma$-ray spectroscopy method coupled to time-of-flight measurements is used to extract ($n,xn\gamma$) cross section values which can be further combined to infer the total neutron inelastic scattering cross section. Cross section data for 18 $\gamma$ transitions (five never measured before) are presented and compared to the data in the literature. Emphasis is especially given to the uncertainty determination to produce partial cross section data as accurate as possible. Due to intrinsic limitations of the experimental method, the use of additional nuclear structure information coupled with theoretical modeling is required to determine the total ($n,n′$) cross section over the whole neutron energy range. We have investigated modeling aspects of the $^{238}$U($n,n$'$\gamma$) cross sections related to the description of compound nucleus and preequilibirum mechanisms as well as the discrete part of nuclear structure. Through comparison between experimental and calculated ($n,n$'$\gamma$) cross sections, we pinpoint inaccuracies in the description of specific reaction mechanisms and challenge recently implemented models. This helps improving the whole modeling of the ($n,n′$) reaction.
- Published
- 2021