Fast and thermal neutrons attenuation through micro-sized and nano-sized CdO reinforced HDPE composites

Abstract

The fast and thermal neutron attenuation properties through polymer composites based on high density polyethylene (HDPE) reinforced by micro-sized and nano-sized Cadmium Oxide (CdO) particles with weight fractions of 10% and 40% have been investigated. This study was carried out to present a new composite material based on HDPE filled with CdO in the form of micro and nano particles to be used as a promising neutron radiation shielding material. The composites were fabricated by compression molding technique and characterized by a scanning electron microscope (SEM). The composites were subjected to fast neutrons generated from 238Pu–Be neutron source with activity 12 × 109 Bq and detected by a Stilbene scintillator. The fast neutron shielding properties were determined in terms of the fast neutron transmission fractions of the composites. The neutron activation method was applied by using Indium foils and Indium foils covered with Cadmium as a detector to study the properties of the thermal and epithermal neutron fluxes of the composites upon exposure to neutron flux generated from 241Am–Be neutron source. It is clear from this study that the transmitted fractions for fast neutron in case of nano CdO/HDPE composites are less than the case of micro CdO/HDPE composites, however, the capture of thermal neutrons inside the micro CdO/HDPE composites is more probable than that in nano CdO/HDPE composites at the same weight fraction. Tensile mechanical testing has been conducted and showed that particle addition percentage and size have significant effect on the mechanical properties of composites. Nano CdO/HDPE composites showed more superior mechanical properties compared to micro CdO/HPDE composites at the same particle addition level.