Iranian Journal of Medical Physics (Dec 2017)
Monte Carlo Study of Several Concrete Shielding Materials Containing Galena and Borated Minerals
Abstract
Introduction: The heavyweight concretes have been widely used for constructing medical or industrial radiation facilities with photon sources. Materials and Methods: In this study, heavy concretes containing galena (PbS) and several borated minerals are proposed as suitable materials against photons. The shielding properties of 21 galena concretes containing seven borated minerals with three mixing patterns were evaluated using MCNP4C Monte Carlo code. The attenuation of the gamma radiation is computed under the conditions of narrow and beam geometries. The x-ray sources with 40, 60, 90, and 120 kVp and gamma rays of 99mTc, 131I, 137Cs, and 511 keV annihilation photons were considered. The photon flux values and the x-ray spectrum after applying all the concretes were compared to the ordinary ones. Regarding the results, more photon attenuations obtained by using high density concretes simulation in comparison to ordinary concrete. Results: The results revealed that the concretes containing orthopinokiolite as the borated material made by the third mixing pattern, had the most photon attenuation. According to the results, the shielding properties of the concretes containing different borated minerals were alike against high photon energies, whereas in low energy photons the attenuation depended on the type of borated mineral used in the concretes. Conclusion: The high-density heavy-weighted concretes could be effectively used as multi-purpose shield for radiotherapy rooms and nuclear reactors due to the borated minerals.
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