Alım, Bünyamin; Özpolat, Özgür Fırat; Şakar, Erdem; Han, İbrahim; Arslan, İbrahim; Singh, V.P.; Demir, Lütfü

In this study, it was focused on the research of new materials with high attenuation efficiency that can be used as radiation shielding material due to the incapability of conventional materials. In accordance with this purpose, the radiation shielding capabilities of four different precipitation-hardening stainless steels (PH-SSs), which are symbolized 15-5PH, 15-7PH, 17-4PH and 17-7PH, were determined both experimentally and theoretically in a wide range of radiation energy. For experimental measurements, two different detectors (Si(Li) and Na(Tl)) and twenty-three different photon energies (from 22.1 to 1332.5 keV) emitted from seven different radionuclides were used in narrow-beam transmission geometry. Phy-X/PSD software were used for theoretical calculations. The theoretically calculated parameters were determined both in the photon energies emitted by the radionuclides used in the experiment and in the continuous energy range of 0.015–15 MeV. Furthermore, in order to make a remarkable assessment of the integration of PH-SSs to nuclear energy applications, the all results obtained have been compared with the corresponding values of Fe-based steel concretes (steel-scrap (SS) and steel-magnetite (SM)), which are widely used as conventional shield materials in nuclear power plants. Moreover, in order to choose the best material to be used in nuclear applications among the PH-SSs, the results were evaluated comparatively in terms of both the characteristics of the materials and the magnitude of the radiation shielding parameters. Consequently, it was concluded that the material with the best radiation shielding performance among the examined PH-SSs was 15-7PH and the radiation shielding performance ranking was generally in the form of 15-7PH ≥ 15-5PH > 17-4PH > 17-7PH > SM > SS. Due to both high attenuation efficiency and superior properties for radiation shielding, it was determined that the PH-SSs can be used as new shielding materials in nuclear applications.

AtıfScopus25·WoS25·OpenAlex27

İncele

Alım, Bünyamin; Şakar, E.; Baltakesmez, Ali; Han, İbrahim; Sayyed, M.I.; Demir, Lütfü

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 (22Na, 60Co, 241Am, 109Cd, 137Cs, 152Eu and 133Ba). 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.

AtıfScopus52·WoS46·OpenAlex57

İncele

Uğurlu, Mine; Alım, Bünyamin; Demir, Lütfü

Kβ/Kα intensity ratios were obtained for Molybdenum-Silver alloys produced in different concentration range in different magnetic fields. It was seen that these values without magnetic field were found slight different from each other for pure Mo, pure Ag, alloyed Mo and alloyed Ag. It was determined that Kβ/Kα intensity ratios change slightly by depending on alloying element composition and it was seen that Kβ/Kα intensity ratios of Mo and Ag are in the range of the literature valuesFurthermore, that these values have same direction with the changing of the magnetic field for all alloying composition may take us conclusion which alloys in different concentration may have same magnetic properties.

AtıfScopus3·WoS2·OpenAlex4

İncele

Uğurlu, Mine; Alım, Bünyamin; Han, İbrahim; Demir, Lütfü

Kβ-to-Kα X-ray intensity ratios of Fe, Ni, Co, Ti, V in pure form and PERMENDUR49 (Fe49Co49V2), KOVAR (Fe54Ni29Co17) and Ti50Co50 alloys were calculated in order to determine valence-electron structure of the samples. The obtained experimental Kβ-to-Kα X-ray intensity ratios were found to be 0.1252 ± 0.0025, 0.1256 ± 0.0027, 0.1298 ± 0.0026, 0.1327 ± 0.0028, 0.1346 ± 0.0027 for pure Ti, V, Fe, Co and Ni, respectively. These values of present pure metals have increased with the increment in atomic number of these pure metals. Also, although the obtained these values for metal atoms in PERMENDUR49, Ti50Co50 and for Fe, Ni metal atoms in KOVAR approximately compatible with respect to results same pure metals, the obtained experimental Kβ-to-Kα X-ray intensity ratios for Co in KOVAR are significantly different from the appropriate values for pure Co metal. Then, the valence-electron populations of these alloys were calculated in order to answer as to why the characteristic properties of the studied alloys are distinct from each other. The valence-electron structures of these metals in pure form and alloys were determined by comparison of the calculated Kβ-to-Kα X-ray intensity ratios with the results of multi-configurations Dirac-Fock (MCDF) calculations to understand the charge-transfer and/or delocalization phenomena of these alloys. The experimental n3d values were found to be 3.2694, 4.7905, 7.7941, 7.9618, 8.500 for pure Ti, V, Fe, Co and Ni, respectively. The calculated 3d and 4s, 4p electron population values for Ti, V and Co in pure form have shown very little deviation from the appropriate values of Ti in Ti50Co50 and Co, V in PERMENDUR49. Also, the deviation for these values is greater for Fe, Ni, in KOVAR, Co in Ti50Co50, Fe in PERMENDUR49 with respect to the corresponding values of pure metals and the largest deviation for these values is observed for Co metal atoms in KOVAR alloy. We have also calculated the weighted average numbers of 3d and 4s, 4p electrons per one atom as well as the superposition of 3d and 4s, 4p electrons, as obtained from pure metal values. While the obtained superposition 3d electron numbers of present alloys exhibit a decreasing tendency as S3d(Ti50Co50) < S3d(PERMENDUR49) < S3d(KOVAR), the obtained weighted average 3d electron numbers of present alloys has opposite tendency (A3d(KOVAR) < A3d(PERMENDUR49) < A3d(Ti50Co50)). The analysis show that valance-electron population of elements in these alloys indicated differences with respect to the pure metal and each other. These differences can be related to type of alloy elements, concentration of alloy elements, charge transfer and/or delocalization phenomena between of individual metal atoms in alloys. Also, the obtained results show that there are alloying effect on valence-electron population due to charge transfer and/or delocalization phenomena.

AtıfScopus15·WoS15·OpenAlex16

İncele

Allm, Bünyamin; Uǧurlu, Mine; Han, Ibrahim; Demir, Lütfü; Akdemir, A.O.; Ekinci, A.; Han, I.; Oztekin, A.; Set, E.; Dadasoglu, F.

In this study, K shell X-ray fluorescence cross-sections (σKα, σKβ and σK), K shell fluorescence yields (ωK) and K to L shell vacancy transfer probabilities (ηKL) of ferromagnetic 3d transition metals (Fe, Co, Ni) were investigated to understand how the relationship between ferromagnetism and these values changes with atomic number by using energy dispersive X-ray fluorescence (EDXRF) technique. The all obtained experimental and theoretical results were comparatively given as a function of the atomic number. It was clearly observed that all of the investigated parameters depend on the atomic number and the ferromagnetism state of the atom.

AtıfScopus3·WoS2·OpenAlex5

İncele

Perişanoğlu, Ufuk; Alım, Bünyamin; Uğurlu, Mine; Demir, Lütfü

The effects of external magnetic field and exciting photon energies on the Kβ/Kα X-ray intensity ratios of various alloy compositions of Ti-Ni transition metal alloys have been investigated in this work using X-ray fluorescence spectroscopy. The spectrum of characteristic K-X-ray photons from pure Ti, pure Ni and TixNi1-x (x=0.30; 0.40; 0.50; 0.60; 0.70) alloys were detected with a high resolution Si (Li) solid-state detector. Firstly, Kβ/Kα X-ray intensity ratios of pure Ti, pure Ni and TixNi1-x alloys were measured following excitation by 59.54 keV γ-rays from a 200 mCi 241Am radioactive point source without any magnetic field and under 0.5 and 1 T external magnetic fields, separately. Later, the same measurements were repeated under the same experimental conditions for 22.69 keV X-rays from a 370 MBq109Cd radioactive point source. The results obtained for Kβ/Kα X-ray intensity ratios of pure Ti, pure Ni, Ti and Ni in various Ti-Ni alloys were evaluated in terms of both external magnetic field effect and exciting photon energy effect. When the results obtained for both exciting photon energies are evaluated in terms of changing of Kβ/Kα X-ray intensity ratios depending on the alloy composition, the tendency of these changes are observed to be similar. Also, Kβ/Kα X-ray intensity ratios for all samples examined have changed with increasing external magnetic field. Therefore, the results obtained have shown that Kβ/Kα X-ray intensity ratios of Ti and Ni in TixNi1−x alloys are connected with the external magnetic field. The present study makes it possible to perform reliable interpretation of experimental Kβ/Kα X-ray intensity ratios for Ti, Ni and TixNi1−x alloys and can also provide quantitative information about the changes of the Kβ/Kα X-ray intensity ratios of these metals with alloy composition.

AtıfScopus32·WoS31·OpenAlex32

İncele

Alim, Bünyamin; Han, Ibrahim; Demir, Lütfü

The effect of external magnetic field on the valence-electron structures of Fe and Ni in various Fe-Ni alloy compositions was investigated by using X-ray fluorescence spectroscopy. Kβ-to-Kα X-rayin-tensity ratios of Fe and Ni in Invar(Fe0.64Ni0.36), Permalloy(Fe0.20Ni0.80) and Fe N - i x 1x Firstly,(x=0, 0.40, 0.52, 0.55, 0.61, and 1) alloys were measured without any magnetic field and under 0.5 and 1 T external magnetic fields, separately. Later, the valence-electron structures of Fe and Ni in both pure form and alloys were obtained by comparison of measured X-ray intensity ratios with the results of multi-configurations Dirac-Fock (MCDF) calculations. The results obtained for valence-electron structures of Fe and Ni in various Fe-Ni alloys were evaluated in terms of magnetic field effect, delocalization and/or charge transfer phenomena. The results have shown that valence electron structure of Fe and Ni in Fe-Ni alloys are dependent on both external magnetic field and concentration of alloy elements.

AtıfScopus16·WoS14·OpenAlex17

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