Assessment on Gamma Radiation Shielding Properties of Molybdenum Doped Bricks

Abstract

Gamma radiation permeability experiments were carried out by preparing a new type of brick mixture with Molybdenum (Mo, Z = 42) additives (0 (B0), 5 (B1), 10 (B2), 20 (B3), 30 (B4), 40 (B5), 50 (B6) %wt). The density of the bricks increased to 2.79 g/cm(3) with increasing Mo content. The bricks were exposed to gamma rays with 81, 276, 303, 356 and 383 keV photon energies emitted from Ba-133 radioactive source and the transmitted intensities were detected using the Canberra Ultra Ge detector. Gamma attenuation characteristics of the bricks were also calculated by mass attenuation coefficients, effective atomic numbers and electron densities using the EpiXS program as a function of gamma-ray energy. And also, the exposure and energy absorption buildup factors of bricks were determined at different mean-free paths and photon energies using EpiXS program. It was observed that as the density of the bricks increased, the radiation shielding properties also increased. The values of the mass attenuation coefficients at 81 keV for B0-B6 bricks were found to vary between 0.229 and 1.08 cm(2)/g. It was found that Z(eff) values were 13.3, 16.1, 17.4, 19.09, 22.5, 25.3 and 26.6 for B0, B1, B2, B3, B4, B5 and B6 samples at 81 keV, respectively. As can be seen from these results, B6 brick has the highest Z(eff) value. And also, the calculated results displayed that the lowest values of exposure buildup factors and energy absorption buildup factors are observed for the B6 brick. The B6 brick containing 50% Mo element has a higher mass attenuation coefficient and effective atomic number values than the other bricks. The values of exposure and energy absorption buildup factors of B6 brick were lower than the values of other investigated samples. The measured and calculated shielding values of the bricks were in close agreement. It has been seen that the shielding results of these new types of bricks, which are low in cost and easy to produce and use, are quite successful.