Yazar "Sayyed, M. I." seçeneğine göre listele

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    Experimental and Monte Carlo simulation study on potential new composite materials to moderate neutron-gamma radiation
    (Pergamon-Elsevier Science Ltd, 2020) Aygun, Bunyamin; Sakar, Erdem; Singh, V. P.; Sayyed, M. I.; Korkut, Turgay; Karabulut, Abdulhalik
    In this study, 12 different concentrations of shielding materials were developed and produced. They were covered with high temperature resistant (1500 degrees C) sodium silicate sealing paste. Epoxy resin was produced by adding different percentages of additive materials such as chromium oxide (Cr2O3), lithium (LiF), and nickel oxide (NiO). The GEANT4 and FLUKA codes of the Monte Carlo simulation toolkit were used to determine the mixing ratios. The total macroscopic cross-sections, effective removal cross-sections, mean free path, half value layer, and transmission neutron number were determined for fast neutron radiation using GEANT4 and FLUKA simulation codes. The mass attenuation coefficient, the effective atomic number and half-value layer (HVL) of the samples were calculated using Phy-X/PSD software. The absorbed dose was measured. In this study, an Am-241-Be neutron source with 74 GBq activity and average neutron energy of approximately 4.5 MeV and a BF3 gas detector were used. Both simulation and experimental measurements were compared with paraffin and conventional concrete. The new composite shielding material absorbed radiation much better than the reference materials. This new radiation shielding composite material can be used in nuclear medicine, transport and storage of radioactive waste, nuclear power plants, and as a shielding material for neutron and gamma radiation.
  • [ X ]
    Öğe
    Fabrication of Ni, Cr, W reinforced new high alloyed stainless steels for radiation shielding applications
    (Elsevier, 2019) Aygun, B.; Sakar, E.; Korkut, T.; Sayyed, M. I.; Karabulut, A.; Zaid, M. H. M.
    Stainless steel is commonly used in radiation applications for its high temperature resistance and fine mechanical properties. In this study, three types of high alloyed stainless-steel samples were produced. Before the production, GEANT4 Monte Carlo simulation toolkit was used to estimate the total fast neutron macroscopic cross sections and gamma mass attenuation coefficients. The hot-pressing process and the powder metallurgy method were applied. We tested samples' chemical and mechanical strength. Samples were exposed to both gamma rays and fast neutrons. The obtained simulation and experimental results for both neutron and gamma radiation are compatible. According to the simulation and experimental results, neutron shielding capacity of the new stainless-steel alloys is higher than the most commonly used 316LN stainless steel in nuclear applications. Among the prepared samples, SSA1 steel has the smallest half value layer at the all examined energies. All the prepared samples posses higher mass attenuation coefficient values and lower half value layer than 316LN steel. This indicates that the produced three new high alloyed stainless-steel samples have high gamma absorption capacity when compared to 316LN steel.