Yazarlar

  • MakaleYalnız künye2026Scopus SJRQ3
    Impact of ZnF2 and PbF2 on the radiation attenuation performance of the fluoride-based bismuth borate glass system

    Aşkın, A.

    Among the various types of glasses, fluoride-based glasses stand out due to their chemical and mechanical stability, low refractive indices, low phonon energies, and low transition temperatures. In this study, key radiation shielding parameters, including the mass attenuation coefficient (µm), half-value thickness (HVL), mean free path (MFP), transmission fraction (T), effective atomic number (Zeff), exposure build-up factors (EBF) and fast neutron removal cross-section (∑R), of the newly developed fluoride-based glass system, xZnF2—(25-x)PbF2—25Bi2O3—49.8B2O3—0.2Cr2O3 (where x is between 0, and 25 mol%), were evaluated. The data was gathered through Monte Carlo simulations, utilizing the Geant4 framework for a germanium detector and the PHY-X/PSD software. The parameters were assessed for gamma-ray energies ranging from 0.284 to 1.33 MeV across all glass samples. The results clearly show that the presence of PbF2 significantly enhances radiation shielding, owing to the high atomic number (Z) of lead. The highest µm and Zeff values were found to be highest and MFP, HVL, and T values were found to be lowest for the glass sample with the highest PbF2 content. Furthermore, the ∑R values of the glasses were observed to decrease as the PbF2 content reduced, highlighting the importance of high-Z elements in neutron absorption. Therefore, gamma and neutron shielding abilities of the studied glasses improve with the addition of PbF2 into the glass structure and glass system containing 25% mole PbF2 exhibits superior gamma and neutron shielding performance compared to shielding concrete.

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  • MakaleYalnız künye2025Scopus SJRQ2
    Phase Stability, Structural Properties, Electronegativity, Mechanical Properties, and Neutron and Gamma-Ray Attenuation Properties of Cantor High Entropy Alloys for Advanced Nuclear Applications

    Tekin, H.O.; Güler, Ömer; Özkul, İskender; AlMisned, Ghada; Baykal, Duygu Sen; Alkarrani, Hessa; Kilic, G.; Mesbahi, A.

    High Entropy Alloys (HEAs) hold considerable potential for sophisticated nuclear applications, offering a vast spectrum of compositional tuning to enhance mechanical properties at high temperatures, as well as to increase resistance to radiation and corrosion. This study explores the suitability of Cantor HEAs, specifically the CoCrFeMnNi matrix enriched with elements such as Zr, Nb, Mo, Hf, Ta, and W, for nuclear applications. These elements were selected for their high atomic numbers and neutron capture cross-sections, vital for enhancing gamma-ray and neutron shielding properties. Utilizing advanced computational and theoretical methods, the elastic modulus of these alloys was theoretically estimated while their radiation attenuation capabilities were evaluated through different Monte Carlo simulation codes. CoCrFeMnNiW demonstrated the highest elastic modulus (340.9 GPa), indicating significant mechanical robustness. The addition of W resulted in superior gamma-ray attenuation, with the lowest gamma-ray transmission factors and highest neutron shielding effectiveness among the studied alloys. The calculated mass attenuation coefficients and effective removal cross-sections values demonstrate the potential of these HEAs to provide effective radiation shielding. Our results showed a clear correlation between the elastic modulus and radiation attenuation properties, suggesting that mechanical stiffness does not compromise shielding capabilities. The comprehensive analysis of thermodynamic and structural parameters, including entropy of mixing, mixing enthalpy, and Valence Electron Concentration (VEC), provided essential insights into phase stability and microstructural characteristics. It can be concluded that CoCrFeMnNiW and its related Cantor HEAs as promising materials for advancing nuclear technology, offering a new horizon for safer and more efficient nuclear systems.

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  • MakaleYalnız künye2024Scopus SJRQ2
    Exploring thermodynamic, physical and radiative interaction properties of quinary FeNiCoCr high entropy alloys (HEAs): a multi-directional characterization study

    ALMisned, Ghada; Guler, Omer; Ozkul, Iskender; Sen Baykal, Duygu; Alkarrani, Hessa; Kilic, G.; Mesbahi, A.; Tekin, H.O.

    To qualify for nuclear applications, materials must meet specific criteria, including mechanical properties, high-temperature behavior, corrosion resistance, and high-temperature oxidation resistance. High Entropy Alloys (HEAs) are particularly suitable for these applications due to their unique properties. Consequently, we conducted a theoretical and simulation-based approaches to assess some critical properties including radiation shielding properties of some quinary FeNiCoCr HEAs. In this study, we focused on quinary FeNiCoCr HEAs, whose corrosion properties have been previously examined in the literature. We investigated the thermodynamic and radiation shielding properties of HEAs with sixteen different compositions. Our methodology included evaluating thermodynamic parameters such as Mixing Entropy (∆Smix) and Mixing Enthalpy (∆Hmix), as well as structural characteristics like Valence Electron Concentration (VEC) and Atomic Size Difference (δ). This allowed us to systematically deduce the phase behavior and stability of various HEAs. Through computational modeling, we assessed the radiation shielding capabilities of these alloys, particularly their effectiveness in attenuating gamma ray and fast neutrons. The results identified FeNiCoCrW as the alloy with the lowest fast neutron removal cross-section values, highlighting its potential for nuclear applications. Its high melting point and the synergistic interplay between its elemental composition and thermodynamic properties suggest broad applicability in extreme environments. Thus, FeNiCoCrW emerges as a promising HEA with multifunctional capabilities, warranting further exploration and potential integration into advanced engineering solutions.

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  • MakaleYalnız künye2020Scopus SJRQ2
    Investigation of the radiation shielding capability of xPbO – (50 - x) BaO – 50 B 2O 3 glass system using Geant4, Fluka, WinXCOM and comparison of data with the experimental data

    Aşkin, A.; Mutuwong, C.; Nutaro, T.; Dal, M.

    In this study, mass attenuation coefficient (μm), transmission fractions (T), effective atomic numbers (Z eff) and half-value layer (HVL) of the xPbO –(50 - x) BaO –50 B 2O 3 (where x=10,20,30,40mol%) glass system have been determined from the Monte Carlo simulations carried out with Geant4 and Fluka simulation toolkits and WinXCOM database software. The calculated results were compared with the experimentally obtained μm values of the selected glass in order to validate the Geant4 model of HPGe detector and Fluka model of NaI(Tl) detectors. T, Z eff and HVL shielding parameters of the studied glass system indicate that increase of PbO content from 10 to 40% results in a better shielding behaviour thanks to the high atomic number of lead.

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  • MakaleYalnız künye2020Scopus SJRQ1
    Assesment of the gamma and neutron shielding capabilities of the boro-tellurite glass quaternary containing heavy metal oxide using Geant4 and Phy-X/PSD database

    Aşkın, A.

    This survey was conducted to reveal the gamma and neutron stopping performance of the 30PbO–10ZnO—(60-x)TeO2—xB2O3 (x = 0, 10, 20, 30, 50% mole) glass quaternary. Gamma and neutron attenuation parameters including the linear attenuation coefficient (μ), transmission fraction (TF), half value layer (HVL), mean free path (MFP), effective atomic number (Zeff), exposure buildup factor (EBF) and fast neutron removal cross-section (∑R) were determined computationally using the Geant4 and Phy-X/PSD database tools and for photon energies ranging between 0.284 MeV and 2.510 MeV. It was found that increasing the B2O3 content from 0% to 50% mole and correspondingly decreasing the TeO2 content from 60% to 10% mole results in a degradation of μ by 18.2% and of Zeff by 28.6% at 0.284 MeV. Due to this decrease in μ and Zeff, the values of TF and HVL increased by 37.3% and 22.4% respectively. In the present study it was also observed that the density (ρ) of glass quaternary decreased with the decreasing content of TeO2, and that the density of glass has a remarkable effect on the photon attenuation characteristics. The Degradation of μ, Zeff, ρ and the increase of TF and HVL proves that the photon attenuation ability of the glasses investigated worsens with decreasing content of TeO2, as Tellurium's atomic number and atomic mass are high compared to those of boron. While the decrease of TeO2 weakens the photon attenuation performance, it was found that fast neutron attenuation increases as ∑R increases from 0.108 to 0.116 for the glass specimens containing 60% and 10% mole of TeO2 respectively.

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  • MakaleYalnız künye2020Scopus SJRQ2
    Evaluation of the gamma and neutron shielding properties of 64 TeO 2+ 15 ZnO + (20 - x) CdO + xBaO + 1 V 2O 5 glass system using Geant4 simulation and Phy-X database software

    Aşkin, A.

    In this study, fast neutron removal cross-section and γ-ray shielding capabilities in terms of mass attenuation coefficient (μm), transmission fractions (T), effective atomic numbers (Zeff), half-value layer (HVL) and exposure build-up factors (EBF) of the 64 TeO 2+ 15 ZnO + (20 - x) CdO + xBaO + 1 V 2O 5 (x= 0 , 5 , 10 , 15 , 20 mol%) glass system have been evaluated using Monte Carlo simulations carried out with Geant4 model of the high-purity germanium (HPGe) detector and Phy-X database software. The results of this study revealed that γ-ray shielding capability of the studied glass system increases with the increase of BaO content and decrease of CdO content in the chemical structure due to the high atomic number (Z) of Ba compared to Cd. The results also showed that increase of BaO fraction in the glass structure weakens the neutron shielding ability and by the use of low Z elements in the composites better shielding performance against neutrons can be obtained.

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  • MakaleYalnız künye2019Scopus SJRQ2
    Comprehensive study on the structural, optical, physical and gamma photon shielding features of B2O3-Bi2O3-PbO-TiO2 glasses using WinXCOM and Geant4 code

    Sayyed, M.I.; El-Mesady, I.A.; Abouhaswa, A.S.; Askin, A.; Rammah, Y.S.

    Glass samples of titanium-lead bismuth borate with the composition of (60B2O3 – 20Bi2O3 – (20-x)PbO – xTiO2), where 0 ≤ x ≤ 10 wt% labeled as BBPT0.0 (x = 0) to BBPT10.0 (x = 10) were synthesized. The melt quenching technique was used in the preparation. The amorphous character and vibrational groups for all samples were confirmed through XRD and FTIR measurements, respectively. The optical band gap (Eopt), Urbach's energy (Eurbach), and the optical dispersion constants have been determined using UV–Vis spectra. Results reveal that the values of the optical band gap energy exhibit a decrease with the TiO2 concentration, in contrast with Urbach's energy which displays a linear increase from 0.43 to 0.64 eV. In addition, the values of single-oscillator energy (Eo) has the same behavior of the optical energy gap (Eopt), while the dispersion energy parameter (Ed) has an inversely behavior. Mass attenuation coefficients (μ/ρ) of the investigated glasses have been computed using the Geant4 simulation toolkit and WinXCOM database software. Geant4 model of a HPGe detector has been employed to perform the Monte Carlo simulations for the glass samples with five thicknesses from 1 to 3 cm at the gamma ray energies in the range of 356–2510 keV. The transmission fractions as a function of the thickness at 356 keV photon energy for all studied glasses has been performed. Half value layer (HVL) was derived from the μ/ρ values. Results showed the studied glasses have good shielding capability according to their mass attenuation coefficients, transmission fractions and HVL values.

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  • MakaleYalnız künye2019Scopus SJRQ1
    Investigation ofthe gamma ray shielding parameters of (100-x)[0.5Li2O–0.1B2O3–0.4P2O5]-xTeO2 glasses using Geant4 and FLUKA codes

    Aşkın, A.; Sayyed, M.I.; Sharma, Amandeep; Dal, M.; El-Mallawany, R.; Kaçal, M.R.

    In the present work, the radiation shielding proeprties of lithium borophosphtellurite glass system with the composition of (100-x) [0.5Li2O-0.1B2O3–0.4P2O5]-xTeO2 (x = 0, 10, 20, 30 and 40 mol%) were reported. The mass attenuation coefficient (μ/ρ) of the selected glass system (LiBPTe0, LiBPTe10, LiBPTe20, LiBPTe30 and LiBPTe40) was calculated at 356 keV, 662 keV, 1173 keV and 1330 keV photon energies by using Geant4 and FLUKA codes and the results were compared to the values obtained theoretically using WinXcom software. The correlation theory has been used to calculate the correlation coefficients (R2) between the results from WinXcom and the both simulations codes (Geant4 and FLUKA) for each sample. Moreover, some other radiation shielding parameters such as effective atomic number, photon transmission, mean free path and half value layer were calculated. The gamma photon transmission results showed that the transmission values of the 356 keV photons are lower than those of energies 662, 1173 and 1330 keV. At 356 keV, the transmission value for LiBPTe0 (at 6 cm thickness) is found to be 0.245 while at the same energy and thickness the transmission value is 0.088 for LiBPTe40. Out of all the glasses considered in present work, LiBPTe40 possesses the highest values of effective atomic number (Zeff). The Zeff values for the present glasses are 8.02, 9.55, 11.16, 12.85 and 14.64 for LiBPTe0, LiBPTe10, LiBPTe20, LiBPTe30 and LiBPTe40 respectively at 356 keV. The mass attenuation coefficient and effetive atomic number results showed that utilization 40% mol of TeO2 significantly improves the gamma ray shielding properties of the selected glass system. The shielding effectiveness of the selected samples was compared with other reference materials namely two radiation shielding glasses and four concretes used in different shielding purposes in terms of the mean free path (MFP) at 356 keV. The results revealed that the MFP of RS-253-G18 is lower than LiBPTe0sample. Moreover, the MFP of ordinary concrete is higher than the MFP of all glasses under examination, thus the investigated tellurite glasses have better attenuation features than the ordinary concrete.

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  • MakaleYalnız künye2019Scopus SJRQ2
    Influence of RE oxides (Eu3+, Sm3+, Nd3+) on gamma radiation shielding properties of lead fluoroborate glasses

    Wagh, Akshatha; Sayyed, M.I.; Askin, A.; Özpolat, Özgür Fırat; Sakar, E.; Lakshminarayana, G.; Kamath, Sudha D.

    Authors report the change in lead fluoroborate glass properties with change in RE2O3 (RE = Eu, Sm, Nd) chemical composition. The RE2O3 exhibited improvement in the radiation shielding properties of the glass samples. The gamma rays shielding capabilities of the samples were studied using the WinXcom software (for Eu2O3, Sm2O3 doped glasses) and Monte Carlo simulation (for Nd2O3 doped glasses). The results exhibited that the mass attenuation coefficient (μm), effective atomic number (Zeff), and half value layer (HVL) depends on the concentration of RE2O3 and addition of the same significantly increased the shielding capabilities of the glass samples against gamma rays. The increase in photon energy revealed the decrease in radiation shielding properties. The reported density and radiation attenuation properties of RE2O3 doped lead fluoroborate glasses are predominant in radiation shielding applications which will be useful in high strength structures. Of all the glass samples 2.5 mol% of Eu2O3, Sm2O3 and Nd2O3 doped glasses showed enhanced shielding properties.

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  • MakaleYalnız künye2019Scopus SJRQ3
    Assessment of the mass attenuation coefficients of granite, basalt, andesite and tuff stones with the Geant4 model of a high-purity germanium detector

    Aşkin, A.; Dal, M.

    In this work, the radiation shielding properties of various natural stones, such as granite, basalt, andesite and tuff, were determined by using Monte-Carlo simulations performed with the Geant4 model of a high-purity germanium (HPGe) detector. Mass attenuation coefficients were calculated for γ-ray energies of 80.9, 140.5, 356.5, 661.6, 1173.2 and 1332.5 keV and for the sample thicknesses between 1 and 7 cm. The results of this study indicate that the stone samples have lower mass attenuation values varying in the range from - 28.8 % to - 3.7 % compared to lead. Among the measured stone samples, the mass attenuation values of tuff stone are closest to lead (above 661.6 keV).

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  • MakaleYalnız künye2019Scopus SJRQ1
    Extensive study of newly developed highly dense transparent PbO-WO3-BaO-Na2O-B2O3 glasses for radiation shielding applications

    Sayyed, M.I.; Aşkın, A.; Ali, Atif Mossad; Kumar, Ashok; Rashad, M.; Alshehri, Ali M.; Singh, Mandeep

    Amorphous PbO – WO3 – BaO – Na2O – B2O3 glass system have fabricated using traditional melt quenching method. The XRD and FTIR spectra confirm the amorphous nature and the various structural properties of the glasses respectively. The various optical properties have been measured in the spectral range 400–4000 cm−1. Also, to understand the shielding ability of the fabricated glasses, we used the Geant4 model of a HPGe detector and WinXcom program to calculate the mass attenuation coefficient (MAC) at six energies between 356 and 2510 keV. In order to confirm the agreement between both methods, we used correlation theory and calculated the correlation coefficients (R2) for each sample. It is found that the R2 values are close to 1 for all samples. The MAC values at 356 keV for the prepared samples lies between 0.221 and 0.246 cm2/g. It is found that the usage of different concentration of PbO (from 50 to 70 mol%) affects the MAC values and thus the attenuation ability of the samples due to the heavier density of the PbO in comparison to B2O3. The effective atomic number results showed that Pb70B10 sample (contains 70 mol% of PbO) was higher than the other samples. Hence, Pb70B10 absorbs more photons than the rest of the prepared glasses.

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