Investigating the effect of adding CdO nano particles on neutron shielding efficacy of HDPE

Abstract

Novel neutron shielding material based on borated high-density polyethylene (HDPE) was prepared in this study. In order to enhance the shielding efficacy of borated HDPE, nano particles of high neutron capture cross section material i.e. of cadmium oxide (CdO) were used as neutron absorber. The CdO nano particles were prepared with composite hydroxide mediated (CHM) method and tested with X-ray diffraction to ensure their structural parameters. The grain sizes of CdO sample obtained from reflection peaks at 2θ = 30.39° and 23.52° were 24.9 nm and 36.1 nm, respectively. The corresponding hkl values and lattice spacing for above-mentioned reflection peaks were found (111) & (110) and 0.29 & 0.38, respectively. These nano scale CdO particles were then mixed in HDPE/B4C composite (containing 10% by wt. of B4C) in predetermining concentrations (i.e. 1%, 2%, and 4% by wt.). The admixture were then pressed in sheets and tested for structural stability and neutron shielding efficacy. The structural stability analysis with FTIR revealed the fact there was no significant alteration in HDPE structure on addition of CdO. The values of effective mass removal cross sections from neutron shielding measurements were 0.1567cm2g-1, 0.1906cm2g-1, and 0.1634cm2g-1 for composites containing 1%, 2%, and 4% CdO, respectively. Furthermore, among all, composite with 2% CdO has been observed of having best shielding properties as it contained the appropriate amount of all the constituents. The higher neutron capture cross section of CdO nano particles was attributed for this significant increase in shielding efficacy of HDPE/B4C/CdO nano composites as compared to pure HDPE and HDPE/B4C composites.