NEUTRON AND PHOTON SHIELDING PARAMETERS OF SOME HYDRIDES AND BOROHYDRIDES

Abstract

The mass attenuation coefficients and effective atomic numbers of three hydrides (MgH2, TiH2, and VH2), seven borohydrides (NaBH4, Mg(BH4)2, Al(BH4)3, KBH4, Ca(BH4)2, Mn(BH4)2, and RbBH4 ) and water were calculated and compared for photon energies in the range 0.015-15 MeV. The fast neutron removal crosssection of the 11 substances were also estimated. The mass attenuation coefficients and effective atomic numbers of the materials were observed to vary with photon energy and chemical composition. The effective atomic number and photon shielding capacity was found to be highest for RbBH4 and least for water throughout the photon energy spectrum. The total fast neutron removal cross section for MgH2, TiH2, VH2, NaBH4, Mg(BH4)2, Al(BH4)3, KBH4, Ca(BH4)2, Mn(BH4)2, RbBH4 and water were 0.111, 0.1652, 0.1998, 0.109, 0.1322, 0.0725, 0.0867, 0.0781, 0.0737, 0.0847 and 0.1029, respectively. Neutron shielding capacity of the materials depended on their hydrogen partial fraction. The hydrides are better neutron shields compared to the borohydrides and water.