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    Evaluation the gamma, charged particle and fast neutron shielding performances of some important AISI-coded stainless steels: Part II
    (Pergamon-Elsevier Science Ltd, 2020) Alim, Bunyamin; Sakar, Erdem; Han, Ibrahim; Sayyed, M., I
    This is the second part of a two-part study on the investigation of radiation shielding performances of some important AISI-coded stainless steels (AISI-302, 304, 321 and 430). Part 1 addressed experimental evaluation by means of measured photon-material interaction parameters. In this second part, we focused on the calculation and discussion of other interaction parameters, which are a guide to choice optimum shielding materials in the nuclear processes for the present AISI-coded stainless steels. The present stainless steels have superior mechanical properties, high temperature and corrosion resistances and these properties can make them favorite materials for nuclear applications. For this reason, firstly, the incoherent scattering/total attenuation ratio (R-inc/total) and equivalent atomic number (Z(eq)) were calculated in the energy region of 0.015-15 MeV. Secondly, the exposure build-up factor (EBF) and energy absorption build-up factor (EABF) were determined to select steels by using Geometric Progression (G-P) fitting method, which have five parameters (a, b, c, d and X-k coefficients), up to penetration depth of 40 MFP at energy 0.015-15 MeV. Thirdly, the mass stopping powers (MSPs; dE/rho dx ; MeVcm(2)/g) and ranges (R-e, R-p and R alpha; mu m) for electron, proton and alpha particle interactions were calculated at energy 10 keV-20 MeV. Finally, the fast neutron removal cross-sections (FNRCSs; Sigma R; cm(-1)) were calculated. To be able to make comparison and a satisfying assessment about radiation shielding capabilities of present AISI-coded steels, all parameters were also computed for ordinary (OC), steel-scrap (SS) and steel-magnetite (SM) concretes (Fe-based steel concretes) that are most commonly used as a shielding material in many nuclear applications. The shielding capabilities of the present stainless steels against both gamma and the fast neutron and charged particle radiation were evaluated in the light of the calculated parameters. As a result of the mutual evaluation of the results obtained for the shielding concretes and the examined stainless steels, it was found that present stainless steels had excellent shielding properties compared to shielding concretes in terms of both photon radiation and particle radiation.
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    Experimental investigation of radiation shielding performances of some important AISI-coded stainless steels: Part I
    (Pergamon-Elsevier Science Ltd, 2020) Alim, Bunyamin; Sakar, Erdem; Baltakesmez, Ali; Han, Ibrahim; Sayyed, M., I; Demir, Lutfu
    The investigation of radiation shielding performances of AISI-302, 304, 321 and 430 stainless steels which have wide range of application because of their superior mechanical properties, temperature and corrosion resistances was aimed in this study. In accordance with this purpose, photon-shielding parameters of these stainless steels were calculated both experimentally and theoretically. These parameters calculated are linear attenuation coefficient, mass attenuation coefficient, mean free path, half-value layer, quarter-value layer, tenth-value layer, total atomic cross-section, total electronic cross-section, effective atomic number, effective electron number and effective conductivity. They were experimentally measured at twenty-three different energies in the range 22 keV and 1333 keV. The photon energies were obtained from seven different radioactive sources (Na-22,Co- 60, Am-24(1) (109)cd , (137)cs, Eu-152 and Ba-133) . The Si(Li) and NaI(Tl) detectors were separately used taking into account of energy-efficient regions to counting process at narrow-beam transmission geometry. In addition, all these parameters were computed at the 15 keV-15 MeV wide energy range, theoretically. In order to make a satisfying assessment about radiation shielding capabilities of AISI 302, 304, 321 and 430 alloys, all calculations were also made for ordinary, steel-scrap and steel-magnetite concretes (Fe-based steel concretes) that are most commonly used as shielding material in many nuclear applications. According to the results obtained, it was observed that the radiation shielding performances of AISI 300 austenitic stainless steel series with containing Ni are superior to that of both AISI 430 ferritic stainless steel and examined concretes.
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    MoO3 reinforced Ultra high molecular weight PE for neutrons shielding applications
    (Pergamon-Elsevier Science Ltd, 2020) Sayyed, M., I; Abdalsalam, Alyaa H.; Taki, Malaa M.; Mhareb, M. H. A.; Alim, Bunyamin; Baltakesmez, Ali; Sakar, Erdem
    Structural, Morphological and neutron attenuation properties of ultrahigh molecular weight polyethylene (UHMWPE) reinforced with molybdenum trioxide composite material obtained by solid state mixing of pellets and powder components via hot pressing have been studied. In this work, Ultra high molecular weight poly-ethylene and MoO3 has been utilized with different concentration using a hot compression iron mold. The changes in the microstructure of the prepared polymer and its particulate composites were evaluated by SEM. In order to investigate the quantitative of all elements used in these samples, we utilized Energy-dispersive X-ray spectroscopy (EDX) to present the profiles of synthesized samples which show a clear peaks C (carbon), and Mo (Molybdenum). The X-ray diffraction of all samples was examined to study the modification of the phase and lattice for UHMWPE before and after the addition of molybdenum trioxide (MoO3). Raman analysis was utilized to explore the crystallinity, molecular interactions, phase, polymorphy, and chemical structure. This technique is based on non-destructive interaction between light with the chemical bonds inside a material. The Raman spectrum for the current work presented within the range of 150-1600 cm(-1). In order to understand the neutron shielding performance for the fabricated UHMWPE with different concentrations of MoO3, 241 Am/Be fast neutron source was used to determine the fast neutron radiation equivalent dose rate. The background absorbed dose rate was measured as 0.98 (+/- 0.017) (mu Sv/h). It was seen that the addition of MoO3 into the UHMWPE enhances the neutron shielding. The dose released from the source was absorbed by 7.71 ( +/- 1.3) %, 18.48 (+/- 2.9) %, 22.26 (+/- 2.4) %, 24.07 (+/- 1.8) % and 26.17 (+/- 1.3) % from UHMWPE with 1, 2, 3, 4 and 5% of MoO3 respectively. Additionally, GEANT4 10.02. p01 version was used to calculate total macroscopic crosssections (TMCS) for the MoO3 doped UHMWPE. According to the results obtained from GEANT4, it was observed that the TMCS values of the UHMWPE increase with increment of the mole fraction of the MoO3 in the structure of UHMWPE examined and that the 5.0% MoO3 sample has the best neutron shielding ability.
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    A study of gamma attenuation property of UHMWPE/Bi2O3 nanocomposites
    (Elsevier, 2019) Abdalsalam, Alyaa H.; Sayyed, M., I; Hussein, Thulfiqar Ali; Sakar, Erdem; Mhareb, M. H. A.; Sakar, Betul Ceviz; Alim, Bunyamin
    In this study, nanocomposite material made of ultra-high molecular weight and bismuth oxide was developed to be used for protection from nuclear radiation. The traditional hot-pressing technique was used for preparing composite samples. The concentrations of Bi2O3 were selected to be 0.5, 1.0, 1.5, 2.0 wt%. In order to study the changes in surface morphology, we examined all samples by scanning electron microscopic (SEM). We evaluated the semi-quantitative of all elements used to fabricate these samples using EDX. Additionally, all samples including pure Bi2O3 has been examined with X-ray diffraction (XRD). Besides that, Raman spectroscopy of all synthesized polymer matrix was measured to explore the different molecular groups. Also, the photon attenuation ability for the present samples was measured experimentally at eight energies varying from 30.8 keV to 383.9 keV using Ba-133 radioactive point source.
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    Study on the radiation attenuation properties of locally available bees-wax as a tissue equivalent bolus material in radiotherapy
    (Pergamon-Elsevier Science Ltd, 2020) Islam, Sazirul; Mahmoud, K. A.; Sayyed, M., I; Alim, Bunyamin; Rahman, Md M.; Mollah, A. S.
    In radiation therapy field, bolus material is frequently utilized when treating different areas of a patient, like at the ears or nose, and to provide build-up of dose to the skin surface. The bolus material must be cost effective, suitably flexible to conform to the surface of the patient, and most importantly should be tissue equivalent. The main objective of this work was to estimate the photon attenuation properties of locally available bees-wax and to assess the feasibility of using this bees-wax as a bolus material practice for treatment of cancer patient. The mass attenuation coefficient (mu/p) values have been calculated by using MCNP5 simulation code over the wide range of photon energy (0.015-10 MeV). Some related parameters such as the effective atomic number and the mean free path were also calculated to understand the photon attenuation ability of the investigated bolus material. The attenuation properties were also computed for water, tissue and commercial bolus materials for comparison. Evaluation of the results showed that the radiation attenuation properties of locally available bees-wax have a good similarity to water/tissue. Referring to the results of this study, it is proposed that locally available bees-wax is a suitable substance to be used as bolus material practice for treat of cancer patient.