Novel metallic Bi-Pb–Cd-Ag alloys for shielding against neutrons and gamma rays

Abstract

Abstract Obtaining high-performance shielding alloys against mixed neutrons and γ-rays is vital in the field of nuclear radiation. In this work, shielding Bi-Pb–Cd-Ag alloys with superior thermal neutron shielding and high ability to attenuate γ-rays were developed. The microstructure, melting behavior, and mechanical properties of the prepared alloys were characterized. The γ-rays mass attenuation coefficients ( μ / ρ ) were obtained using WinXCom program in the energy range of 0.015–15 MeV. The shielding parameters including atomic and electronic cross-sections (σ a and σ e), effective atomic number (Z eff ), effective electron density (N eff ) were calculated. The exposure buildup factor (EBF) using a geometric progression (GP) fitting method was estimated. The experimental measurements were carried out at 662 and 1173, 1332 keV of 137Cs and 60Co isotope sources, respectively using a scintillation gamma spectrometer NaI(Tl) detector. The calculated results of WinXCom are consistent and in agreement with the experimental values of μ / ρ . The macroscopic effective removal cross-section ( ∑ R ) of the samples for fast neutrons were calculated. Also, the attenuation of thermal neutrons through the prepared alloys has been investigated. It was found that the alloy containing 30% Cd complies with the compromise between superior thermal neutron attenuation besides its superior ability to attenuate γ-rays with good mechanical strength and high ductility.