GAMMA AND NEUTRON SHIELDING BEHAVIOR OF SPARK PLASMA SINTERED BORON CARBIDE-TUNGSTEN BASED COMPOSITES

摘要

In this study gamma and neutron attenuation properties of boron carbide-tungsten (B_4C-W) based composites were investigated. B_4C-W based composites were produced by spark plasma sintering (SPS) method. W additions were 5%, 10%, and 15% by volume. Samples with theoretical densities were obtained. Occurance of W_2B_5 phase with a reaction between B_4C and W particles were observed with XRD and SEM investigations. The materials were subjected to gamma and neutron sources. Cs-137 and Co-60 gamma radioisotopes were used as gamma, and Pu-Be Neutron Howitzer was used as neutron source. Linear and mass attenuation coefficients of the composites were carried out for gamma sources by using gamma transmission technique. Furthermore, total macroscopic cross-sections of the samples were determined for Pu-Be neutrons. In conclusion, increasing W ratio in the B_4C-W system causes higher gamma attenuation behavior for gamma sources, but the macroscopic cross-sections of the B_4C-W composites decrease by increasing W concentration.