Shielding performance of metal oxide nanoparticles-doped polypropylene composites against gamma rays and neutrons exposure

Abstract

This paper compares the theoretically measured attenuation parameters of a new type of nanocomposite shielding materials against γ-rays (energy range of 0.015 to 15 MeV) and neutrons (energy range of 0.0254 eV to 4.5 MeV) with the ones calculated using Phy-x/PSD and NGCal software. Nine nanocomposites (acted as shields) were made using hematite (Fe2O3) and cadmium oxide (CdO) nanoparticles-doped polypropylene (PP). The influence of various doping contents (x = 15, 30, 50, 75 wt%) on the shielding characteristics of the nanocomposites of composition (100-x)PP-(x)Fe2O3 and (100-x)PP-(x)CdO were examined. Radioactive isotopes like Am-241 (0.06 MeV), Ba-133 (0.081 and 0.356 MeV), Cs-137 (0.662 MeV), and Co-60 (1.173 and 1.333 MeV) were used as γ-ray sources. In addition, thermal (0.0254 eV) and fast neutrons (4 and 4.5 MeV) were used. The results revealed that the shielding performance of the proposed nanocomposites was significantly enhanced due to nanoscale metal-oxide doping. The mass attenuation coefficient (MAC) values of the PP sample impregnated with 75 wt% CdO nanoparticles varied from 0.768 cm2/g to 27.788 cm2/g and 0.018 cm2/g to 0.034 cm2/g at energies of 0.015 MeV and 15 MeV. Furthermore, it was observed that the values of fast neutron removal cross-sections (FNRCS) were impacted with an increase of 0.1162 cm-1 to 0.1225 cm-1. In addition, the linear attenuation factor (LAF) values improved intensely with increased CdO nanoparticle concentrations. The shield made using 75 wt% of CdO displayed the best shielding performance against high energy neutrons and γ irradiation.