Neutron-induced inelastic scattering cross-section measurement of <sup>52</sup>Cr
Authors: TAN Boyu  , WANG Zhaohui  , WU Hongyi  , HAN Yinlu  , XIAO Shiliang  , WANG Hao  , WANG Wenye  , WANG Jimin  , LI Yuzhao  , LIU Yingyi  , WANG Jincheng  , TAO Xi  , RUAN Xichao  ,   1 Key Laboratory of Nuclear Data, China Institute of Atomic Energy, Beijing 102413, China;,   2 School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China
Published: February 2025

With the development of next-generation reactors, the demand for higher precision in nuclear data has increased significantly to ensure operational efficiency and safety. In particular, the inelastic scattering cross-section data is one of the critical parameters in nuclear reactor physics calculations, directly impacting neutron economy, thermal-hydraulic design, and safety analysis. Stainless steel is widely used in the nuclear industry. Chromium (Cr) is one of the primary alloying elements in stainless steel, and <sup>52</sup>Cr is the most abundant isotope in nature. However, the measurement of the inelastic scattering cross-section of <sup>52</sup>Cr remains unexplored domestically, making the study of the <sup>52</sup>Cr (n, n' γ) reaction cross-section crucial for nuclear reactor calculations. In this study, the HI-13 tandem accelerator at the China Institute of Atomic Energy was utilized to generate neutron beams with energies of 5.62 MeV, 6.24 MeV, and 7.95 MeV via the D (d, n)<sup>3</sup> He reaction. These neutrons were used to bombard a <sup>52</sup>Cr target. Four CLOVER detectors were positioned at 30°、70°、110° and 150° relative to the beam direction in the horizontal plane. The prompt γ-ray method was employed to measure the inelastic scattering cross-section using an HPGe detector array. For the first time in China, the experimental production cross-sections of five inelastic γ-rays with energies of 647.47 keV, 935.54 keV, 1333.65 keV, 1434.07 keV, and 1530.67 keV were obtained. Additionally, theoretical model calculations were performed to determine the inelastic scattering cross-sections of neutrons with energies below 20 MeV interacting with <sup>52</sup>Cr. The data analysis of the experiment accounted for γ-ray self-absorption correction, neutron flux attenuation and multiple scattering correction. The total experimental uncertainty included contributions from measurement uncertainty, correction term uncertainty, and standard cross-section uncertainty. The results show that the γ-ray production cross-sections obtained at the three neutron energy points are in good agreement with the measurements by L.C. Mihailescu et al. within the error margins, and the uncertainties are smaller. However, significant discrepancies were observed between the theoretical model calculations and the experimental data, which may be attributed to the lack of experimental information on the high-excitation-energy levels in the <sup>52</sup>Cr level scheme. This study not only fills a gap in the domestic measurement of the <sup>52</sup>Cr inelastic scattering cross-section but also provides important nuclear data for the design and optimization of next-generation reactors.