First principles calculation for generating new thermal neutron scattering data for Zirconium hydride. (September 2022)

• Record Type: Journal Article
• Authors: El Barbari, M.; El Bardouni, T.; El Yaakoubi, H.; Boulaich, Y.; Lahdour, M.; Ziani, H.; Berriban, I.
• Is Part Of: Applied radiation and isotopes. Volume 187(2022)
• Publication Date: 2022-09
• Subjects: Zirconium hydride -- Phase structures -- Phonon DOS -- Cross sections; Radiology -- Periodicals; Radiation -- Industrial applications -- Periodicals; Nuclear chemistry -- Periodicals; Internet resource; Periodical; 660.298
• DOI: 10.1016/j.apradiso.2022.110313
• Languages: English
• ISSNs: 0969-8043

Abstract

Abstract: Lattice parameters of materials have the same magnitude as the energy of thermal neutrons in reactors, which directly affects the neutron cross section and its energy. While they are thermalized, incident neutrons can lose or gain energy during their interactions with materials components. Since several decades, methods and models were developed in the aim to generate nuclear data sub-libraries required in correcting neutrons interactions cross sections at thermal energies. However, very few experimental works were dedicated to this field. In this paper we focus our efforts on reviewing the theoretical models and their adequacy in describing thermal scattering events in the aim of proposing new formalisms to calculate the density of states (DOS) and phonon responses of zirconium hydride material, which constitutes an important moderator of neutrons in TRIGA reactors fuel elements. Generally the effects of thermal scattering are provided in nuclear data evaluations by a thermal sub-library ENDF file 7. Data in file 7 are described by the known thermal scattering law S ( α, β ) which is a function of momentum transfer and energy transfer parameters α and β respectively. The thermal scattering law has been used to calculate the double differential cross sections and the corresponding results are presented. Although the comparison with other models shows satisfactory results, no previously personalized use of data may be the raison of its usefulness in some cases and not in others. Highlights: To study the possible existing phases of zirconium alloys in the fuel and cladding materials of a nuclear reactor. The calculation of densities of states of phonons the ABINIT code. The generation of new thermal scattering law S( α, β ) libraries using the LEAPR module of NJOY2016 code. Comparing the effect of our new thermal scattering law data coupled with the effectiveness of considering the different phases of ZrHx on the neutron scattering cross sections.