نوع مقاله : مقاله پژوهشی
نویسندگان
دانشکده فنی مهندسی، گروه مهندسی هستهای، دانشگاه آزاد اسلامی واحد علوم تحقیقات، تهران، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Protection against ionizing radiation has been a global concern for decades. In the field of radiation protection, photons and neutrons are particularly important, because these rays do not have an electric charge and have a high penetration depth in different materials. One of the most useful neutron sources is californium-252, which produces a very high flux of fast neutrons along with gamma photons. Considering the portability of californium-252, one of its advantages is the treatment of cancer with alpha particles by capturing its neutrons by boron-10. Therefore, it is necessary to design a shield with suitable materials and reduce the volume and weight of the shield in order to facilitate the moving of the source with the shield and to reduce the gamma and neutron dose. In this research, by using a pre-designed shield, the protective properties of kennertium, stainless steel, tungsten carbide and polyethylene/bismuth (78.5% wt.) to reduce gamma equivalent dose and magnesium borohydride, aluminum borohydride, zirconium borohydride, lithium borohydride, thorium borohydride, beryllium borohydride, premadex and sodium cyanoborohydride to reduce Neutron equivalent dose was simulated with the help of MCNPX Monte Carlo code. The simulation results indicated that magnesium borohydride with a thickness of 17.5 cm and kennertium with a thickness of 1 cm led to a 5.5% decrease in the total dose rate at a distance of 1 meter from the source and a 39% decrease in the shielding thickness compared to the reference article (the material and the thickness are stated in the text). Therefore, magnesium borohydride and kennertium were determined as the best neutron and gamma absorbers, respectively. In the continuation of this study, the development and investigation of other advanced materials are suggested as an optimal shielding in a mixed neutron and gamma field.
کلیدواژهها [English]