Calculation of gamma-ray attenuation parameters for locally developed shielding material: Polyboron

Abstract

In the present study, the mass attenuation coefficient (μm) has been calculated analytically for a locally developed shielding material, polyboron, and compared with the values obtained from the WinXCom code, a Windows version of the XCOM database at the photon energy range 0.001 MeV–20 MeV. A good agreement has been observed between these two values. The linear attenuation coefficients (μ) and relaxation lengths (λ) have also been calculated from the obtained μm values and their variations with photon energy have been plotted. For comparison, other four shielding materials- ordinary concrete, pure polyethylene, borated polyethylene and water have also been studied. The obtained result shows that μm, μ and λ strongly depends on the photon energy, chemical composition and density of the shielding materials. The values of μm and μ of polyboron have been found greater than those of pure polyethylene and borated polyethylene but less than those of ordinary concrete and water at low photon energy range; and at the intermediate photon energy range (0.125 MeV–6 MeV), all the sample materials have approximately the same μm values. It has also been noticed that polyboron has the medial relaxation length (λ) over the entire photon energy range. The total mass attenuation coefficient (μm) and linear attenuation coefficient (μ), Half Value Layer (HVL) and Tenth Value Layer (TVL) of the five sample materials for some common gamma sources have been worked out and the transmission curves have been plotted. The curves exhibit that the transmission factor of the sample materials decreases with the increase in shielding thickness. The results of this study can be utilized to comprehend the shielding effectiveness of this locally developed material.

Keywords

• Mass attenuation coefficient (μm)
• Linear attenuation coefficient (μ)
• Half Value Layer (HVL)
• Tenth Value Layer (TVL)
• Relaxation lengths (λ)