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The calculation of stopping power and range for radium, thorium and uranium using new electronic potential energy function
(Pergamon-Elsevier Science Ltd, 2019) Usta, Metin
In this paper, the electronic stopping power and range calculations of radium-226, thorium-229 and uranium-236 isotopes, which are natural alpha emitters, were performed for the alpha particles in the 200 keV-10 MeV energy range. The effective charge approach based on the Bethe-Bloch theory for the stopping power, the continuous slowing down approach and the Simpson 1/3 method were used for calculation of the range. To this end, new electronic potential energy functions were primarily obtained by using the Lie group method for the target elements. For electronic charge density, relativistic atomic natural orbitals based on Gaussian type orbitals were selected. The results were compared with the existing data sets in the literature. The potential energy curves obtained were irregular at certain distances, but were quite close to that of the multi-atomic target systems. The stripping distances of the target atoms and the corresponding potential energy values were determined from the potential energy functions. It was observed that the stopping power and range values were generally compatible with the SRIM and ICRU 49 data at specific error rates. By adding some correction factors to the calculations, it is predicted that the discrepancies and the error rates may be reduced. The results acquired with this innovative work can be used in the interaction of charged particles with matter, applications related to alpha decay and shielding.
Continuous slowing-down approximation ranges of biological materials for 0.05-10 MeV alpha particles by using different approach methods
(Pergamon-Elsevier Science Ltd, 2021) Usta, Metin
The goal of this study was to calculate the range values of alpha particles in bone, MS20 tissue substitute, and muscle targets using different approach methods. The range values were calculated using Gauss quadrature, Simpson 1/3, and trapezoidal numerical integration methods in continuous slowing-down approximation (CSDA). Overall, the Gauss quadrature method gave the best CSDA range values for the target materials. These results will be conducive to studies involving the interaction of radiation with biological materials.
Effect of current density on structural and radiation shielding characteristics of NiCoB/hBN composites
(Pergamon-Elsevier Science Ltd, 2022) Usta, Metin; Karahan, Ismail Hakki
Radiation causes genetic changes in living systems, especially by adversely affecting health of human beings, animals and plants. The need for shielding for protection against radiation still maintains its importance today. In this study, hexagonal boron nitride ceramic material was doped with Ni-Co-B at different current densities and the absorption properties of these samples against alpha, beta and gamma radiation were investigated. It was found from the XRD and SEM images as well as radiation absorption rates that the radiation absorption properties of these samples decreased with the increase in current density. The coalescence level of hBN particles was determined to be 0.68 at a maximum current density of 100 mA/cm(2). It was observed that the absorption percentages for each radioactive beam source were between 0.76 and 5.48 at 50 mA and between 0.10 and 1.53 at 150 mA. The results were calculated and compared with the range values of the databases available in the literature, and it was procured that the results were compatible. This study will contribute to studies on shielding for radiation protection.
The effect of the ceramic amount on the radiation shielding properties of metal-matrix composite coatings
(Pergamon-Elsevier Science Ltd, 2020) Usta, Metin; Tozar, Ali
In this study, Ni-B metal matrix composite coatings reinforced with hexagonal boron nitride (hBN) nanoparticles were fabricated on 304L steel substrate with electrochemical deposition method. The volume fraction of hBN was 6-26%. The phase and morphological characteristics were determined via XRD and FE-SEM, respectively. Ni-B/hBN composite coatings were irradiated with Am-241, Sr-90 and Co-60 radioactive sources, which are typical alpha, beta and gamma-ray sources, respectively. Percent absorption rates were acquired according to the hBN volume fractions of each irradiated sample. Accordingly, it was found that the absorption rates also raised as the volume fractions of the hBN in the coating increased. In order to control the findings, stopping power and range values were procured with SRIM and ESTAR databases. Similar to the absorption rate, increasing volume fractions increased the stopping power and decreased the range values. Nuclear radiation shielding properties of metal matrix composite materials are presented here for the first time. This study revealed the importance of Ni-B/hBN composite coatings in terms of radiation shielding properties.
Effects of annealing on morphological, structural and electrical properties of thermally evaporated WO3 thin films
(Academic Press Ltd- Elsevier Science Ltd, 2012) Usta, Metin; Kahraman, Suleyman; Bayansal, Fatih; Cetinkara, Haci A.
Tungsten trioxide (WO3) thin films were prepared by thermal evaporation method onto quartz substrates at room temperature. Effect of annealing temperature (from 200 to 800 degrees C) to morphology, crystallographic structure and electrical properties were investigated. In order to investigate the temperature dependant resistivity properties of the films dark current-voltage measurements were done at the temperatures of 30, 60, 90, 120 and 150 degrees C. From the AFM pictures it is seen that the increasing annealing temperature causes an increase in grain sizes. At elevated temperatures the grains combine to each other and thus form continuous and homogenous surfaces. From the XRD patterns it was seen that the as-prepared and annealed films at 200, 300, 310 and 320 degrees C were amorphous. On the other hand at 330 degrees C and higher temperatures the films were found as in crystallized structures (monoclinic phase). From the current-voltage measurements it was seen that the contacts areohmic and the current increased with increasing temperatures. From the calculated values it was seen that the produced films shows good semiconducting nature. (C) 2012 Elsevier Ltd. All rights reserved.
Energy loss analysis from RBS spectrum of thin Cu2ZnSnS4 (CZTS) film
(Bitlis Eren Üniversitesi, 2019) Usta, Metin
The goal of this work is to offer an alternative method to the available literature on determining the energy loss of CZTS thin films. For this purpose, thin CZTS film structures were first produced by sol-gel method and then the RBS spectrum was received with RBS detector irradiating this structure with 3.034 MeV proton beams in a microbeam chamber. The energy calibration was implemented to this spectrum, where the it was fitted with SIMNRA program. In the RBS spectrum of the thin film generated, a method for the calculation of energy loss was used for the position and energy width analysis of the corresponding peaks and a polynomial fit was obtained from the stopping power of the CZTS thin film by making certain approaches. Also, the effective charge approach that we used in our previous studies for the stopping power was employed with atomic natural orbitals and it was founded that the results were close to each other at certain error rates. The data obtained from this study will inspire the future studies on the interaction of radiation with matter.
Etkin yük yaklaşımı kullanarak protonlar için Z=2-54 elementlerin durdurma gücü üzerine bir çalışma
(Erzincan Üniversitesi, 2019) Usta, Metin
Durdurma gücü, hedef içerisindeki elektronlar ve çekirdeğin Coulomb alanı etkileşmesi nedeniyle yüklü parçacıkların birim uzunluk başına ortalama enerji kaybıdır. Durdurma gücünün atom fiziği, nükleer fizik ve uygulamaları, radyasyon dozimetrisi gibi birçok alanlarda önemli uygulamaları vardır. Bu çalışmanın amacı 1 keV-1 GeV enerjili protonlar için Z=2-54 atom numaralı elementlerin Bethe-Bloch teorisine dayalı etkin yük yaklaşımı yöntemi kullanılarak çarpışma durdurma gücünü hesaplamaktır. Bunun için öncelikle hedef elementlerin etkin yük, etkin ortalama uyarılma enerjileri ve potansiyel enerji fonksiyonları belirlendi. Elektronik yük yoğunluğu için Roothaan-Hartree-Fock atomik dalgafonksiyonları seçildi ve hedef atomların etkin yükünün protonların enerjisiyle değişimi incelendi. Ardından elde edilen hedef atomların etkin yükleri kullanılarak çarpışma durdurma gücü değerleri hesaplandı. Atom numarası ve gelen protonların enerjisi arttıkça etkin yük değerlerinin arttığı görüldü. Durdurma gücü değerlerinin ise atom sayısı arttıkça azaldığı ve durdurma gücüne ait maksimum noktalarının yüksek enerjilere doğru kaydığı belirlendi. Hedef elementlerden karbon atomu için hesaplanan durdurma gücü değerleri literatürde mevcut ICRU 49, SRIM, CasP ve Janni’nin verileriyle karşılaştırıldı. Sonuçların belirli hata oranlarında literatür verileriyle oldukça uygun oldukları gözlendi. Ayrıca bu çalışmada kullanılan etkin yük yaklaşımının 1 MeV’den düşük enerjilerde de kullanılabileceği anlaşıldı.
Irradiated rGO electrode-based high-performance supercapacitors: Boosting effect of GO/rGO mixed nanosheets on electrochemical performance
(Elsevier Sci Ltd, 2022) Karaman, Onur; Kariper, I. Afsin; Korkmaz, Satiye; Karimi-Maleh, Hassan; Usta, Metin; Karaman, Ceren
Supercapacitors are seemed to be one of the most promising choices as an energy storage system. However, there is still a gap in enhancing its energy density values and cyclic stabilities throughout a facile approach. Herein, it was aimed to propose a facile and effective way to fabricate high-energy supercapacitor electrode material based on reduced graphene oxide (rGO) nanostructure. Bearing this in mind, the bulk rGO powder was irradiated by various beam sources including Co-60, Am-241, Na-22, and Sr-90, and the resultant irradiated rGO samples were utilized as the electrode active material to fabricate symmetrical supercapacitor cells. The irradiated rGO samples were characterized both physicochemically and electrochemically. The physicochemical characterizations revealed that as a consequence of the irradiation, both GO and rGO nanosheets were formed in the resultant powder and the d-spacing of the graphene nanosheets were expanded. The highest electrochemical performance metrics were acquired for Sr-90 irradiated rGO electrode-based supercapacitor cell with the specific capacitance value of 585.44F.g ? 1 at 0.2 A.g ? 1, and outstanding capacitance retention performance of 97.14% for the 5000th CV cycles at 200 mV.s ? 1. Moreover, the energy density and power density values were comparable to other commercial energy storage systems such as lead-acid and nickel-metal hybrid batteries. Hence, it can be speculated that these pioneering breakthroughs could pave the way for cutting-edge high-energy supercapacitors based on rGO-derivatives with superior electrochemical performance metrics, as well as engineering of highperformance rGO-based materials to be employed in various energy applications.
Measurement of energy transitions for the decay radiations of 75Ge and 69Ge in a high purity germanium detector
(Elsevier, 2018) Aydin, Gural; Usta, Metin; Oktay, Adem
Photoactivation experiments have a wide range of application areas in nuclear, particle physics, and medical physics such as measuring energy levels and half-lifes of nuclei, experiments for understanding imaging methods in medicine, isotope production for patient treatment, radiation security and transportation, radiation therapy, and astrophysics processes. In this study, some energy transition values of the decay radiations of Ge-75 and Ge-69, which are the products of photonuclear reactions (gamma, n) with germanium isotopes (Ge-75 and Ge-69), were measured. The gamma spectrum as a result of atomic transitions were analysed by using a high purity semiconductor germanium detector and the energy transition values which are presented here were compared with the ones which are the best in literature. It was observed that the results presented are in agreement with literature in error range and some results have better precisions. (C) 2018 Elsevier B.V.
Quantitative Analysis for RBS and PIXE Spectrums of Thin $Cu_2ZnSnS_4$ (CZTS) Films
(2021) Usta, Metin
The objective of this work is to introduce a different technique to existing studies that determine the stoichiometric ratios of thin CZTS structures. To this end, the CZTS targets were propagated by sol-gel process and later RBS and PIXE spectra were achieved by irradiating these samples with protons of 3.034 MeV energy into microbeam chamber. RBS spectrum was taken with RBS detector and PIXE spectra were collected with IGe and SDD detectors. As energy calibration was performed to these spectra and the RBS spectrum was fixed with the SIMNRA simulation program and the PIXE spectra adjusted with the Gaussian function. In the RBS spectrum, quantitative analysis measurements could not be performed due to the presence of Mo peak, which supplies electrical conductivity, while PIXE spectra results close to expected values. For this, least squares regression method were carried out PIXE spectra for the reference material, and the analytical elemental amount ratios for CZTS were specified with the calibration coefficients found. It was observed that the results acquired with the SDD detector were convenient with the required values, except sulfur content. This technique is a fast and simple method that can be employed analytically to help improve the accuracy of the existing methods in the literature that used to determine the constituent quantities and the depth analysis of thin films. However, this method should be compared with inverse least squares model or eigenvector quantitative analysis methods.
Radioactive rays shielding film: coating on amorphous glass
(Springer, 2020) Kariper, I. Afsin; Meydaneri Tezel, Fatma; Usta, Metin
In this study, boron and lead compounds were coated on amorphous glass. Chemical bath deposition method was used for coating. Films were produced in the baths with pH: 9-12. Some of the produced films were directly analyzed, whereas some of them were analyzed after annealing at 500 degrees C. The characterization of the films was performed by XRD, while surface characterization was performed by SEM and EDX analysis. The study was finalized by performing radioactive analyzes of the films. Am-241 isotopes were used as the radioactive source for Alpha rays, Co-60 for Gamma rays and Sr-90 for Beta rays. According to the results, it was found that the films produced at pH: 9-10 had low optical transmittance but were able to absorb alpha and beta particles considerably. However, despite the high optical permeability of the films produced at pH: 11-12, their absorption of radioactive particles was found to be lower than the others. As a result, it was found that the absorption characteristics of the films produced at baths with different pH depend on the relative rate of boron and lead elements found on the surface.
The relationship between ceramic additives among structural, morphological, shielding, and stopping power features of BN/ZnFe metal matrix materials
(Elsevier Ltd, 2024) Usta, Metin; Karahan, İsmail Hakkı
Ionizing radiation has many negative effects on human health. These include eye and skin disorders and DNA damage inside cells. To eliminate or reduce these destructive effects of radiation, economical, low-corrosion, effective shielding materials with high absorption properties are needed. In this study, zinc-iron-based metal matrix composite materials with various proportions of boron nitride were produced on steel substrates. The structural and surface properties of the materials were examined with XRD and SEM images, respectively. These structures were irradiated with radioactive Am-241, Sr-90, Na-22, and Co-60 sources for their radiation shielding properties. Then, the absorption ratios in the samples were investigated according to the reinforced ceramic amounts in their content. In addition to the experiment, the stopping power and range values of the samples were calculated to check the reliability of the results. ZnFe alloys and composites are based on the dominant peaks of the heta (?) phase of zinc. The amount of boron nitride added to the electrolyte significantly affected the crystal structure, while the incorporation of boron nitride into the zinc-iron matrix impressed the average grain size of the coating. The microstrain and dislocation densities of the film first decreased to 15 g/L and then increased depending on the ion diameter. The BN doping made the porous surface smooth, crack-free, and compact. It was found that the absorption rates for radiation increased as the amount of boron nitride in the samples increased. According to the rising amount of boron nitride, the absorption percentages are between 1.88 and 6.19% for alpha particles, 0.78–3.06% for electrons, 0.77–6.56% for positrons, and 0.61–6.34% for gamma photons. When the stopping power and range values were averaged, the amount of boron nitride increased directly and inversely with the stopping power and range values, respectively. © 2024 Elsevier Ltd
Stopping power and dose calculations with analytical and Monte Carlo methods for protons and prompt gamma range verification
(Elsevier, 2018) Usta, Metin; Tufan, Mustafa Cagatay; Aydin, Gural; Bozkurt, Ahmet
In this study, we have performed the calculations stopping power, depth dose, and range verification for proton beams using dielectric and Bethe-Bloch theories and FLUKA, Geant4 and MCNPX Monte Carlo codes. In the framework, as analytical studies, Drude model was applied for dielectric theory and effective charge approach with Roothaan-Hartree-Fock charge densities was used in Bethe theory. In the simulations different setup parameters were selected to evaluate the performance of three distinct Monte Carlo codes. The lung and breast tissues were investigated are considered to be related to the most common types of cancer throughout the world. The results were compared with each other and the available data in literature. In addition, the obtained results were verified with prompt gamma range data. In both stopping power values and depth-dose distributions, it was found that the Monte Carlo values give better results compared with the analytical ones while the results that agree best with ICRU data in terms of stopping power are those of the effective charge approach between the analytical methods and of the FLUKA code among the MC packages. In the depth dose distributions of the examined tissues, although the Bragg curves for Monte Carlo almost overlap, the analytical ones show significant deviations that become more pronounce with increasing energy. Verifications with the results of prompt gamma photons were attempted for 100-200 MeV protons which are regarded important for proton therapy. The analytical results are within 2%-5% and the Monte Carlo values are within 0%-2% as compared with those of the prompt gammas.
Stopping power and range calculations in human tissues by using the Hartree-Fock-Roothaan wave functions
(Pergamon-Elsevier Science Ltd, 2017) Usta, Metin; Tufan, Mustafa Cagatay
The object of this work is to present the consequences for the stopping power and range values of some human tissues at energies ranging from 1 MeV to 1 GeV and 1-500 MeV, respectively. The considered human tissues are lung, intestine, skin, larynx, breast, bladder, prostate and ovary. In this work, the stopping power is calculated by considering the number of velocity -dependent effective charge and effective mean excitation energies of the target material. We used the Hartree-Fock-Roothaan (HFR) atomic wave function to determine the charge density and the continuous slowing down approximation (CSDA) method for the calculation of the proton range. Electronic stopping power values of tissues results have been compared with the ICRU 44, 46 reports, SRIM, Janni and CasP data over the percent error rate. Range values relate to tissues have compared the range results with the SRIM, FLUKA and Geant4 data. For electronic stopping power results, ICRU, SRIM and Janni's data indicated the best fit with our values at 1-50, 50-250 MeV and 250 MeV-1 GeV, respectively. For range results, the best accordance with the calculated values have been found the SRIM data and the error level is less than 10% in proton therapy. However, greater 30% errors were observed in the 250 MeV and over energies.
A study on the textural and radiation attenuation properties of nickel-cobalt-boron-based metal matrix materials
(Pergamon-Elsevier Science Ltd, 2023) Usta, Metin; Karahan, Ismail Hakki
Radiation has negative deterministic and stochastic effects on the human body, such as decreased repairability of cells and DNA damage. In order to avoid the effects of exposure to external radiation, the need for shielding is also very important, along with observing the rules of time and distance. In this study, Ni-Co-B material was produced on steel substrates as an alternative to existing shielding materials, and hexagonal boron nitride was doped into these structures at different proportions. Structural and morphological properties of the produced materials were obtained with XRD and SEM images. Then, these samples were irradiated with alpha, beta, and gamma rays and their radiation attenuation properties were examined according to the current types in the production phase. To verify the results, stopping power and range values of the materials were calculated for the same beams. It was determined that the hexagonal boron nitride incorporating levels increased as one went from direct current to alternating current. The maximum incorporation level was approximately 1.1%. It was specified that the amount of boron in the material was directly proportional to the current intensity. It was observed that finer granular structures were formed under alternating current compared to direct current. It was found that gamma rays were absorbed the most and positrons were absorbed the least in the samples. According to the increasing hexagonal boron nitride ratios, the absorption percentages of alpha, electron, positron, and gamma rays varied as 0.13-3.75, 0.51-2.24, 0.015-1.04, and 0.72-8.37, respectively. As the hexagonal boron nitride ratios increased and changed from direct current to alternating current, both radiation absorption rates and stopping power increased. It was understood that gamma photons had a greater range in alternating current, and the range increased non-uniformly with the hexagonal boron nitride ratio.
Use of Gaussian-type functions for flux-based dose calculations in carbaon ion therapy
(Springer, 2020) Usta, Metin; Aydin, Gural
In radiation therapy, it is very important to ensure that the radiation dose is correctly delivered to the patient. This is achieved by obtaining quantitative dose measurements for beam calibration in the treatment planning system. Dose calculations should be performed with the required accuracy to a degree of uncertainty of less than 1%. The measurement of the absorbed dose in and around body tissues irradiated with carbon ions requires careful use of materials selected from established phantom and radiation detectors. The main advantage of such materials is that when information on the energy and nature of charged particles at the desired point is incomplete or inaccurate, they can allow determination of the absorbed dose. In general, radiation interactions in a tissue representation caused by carbon ions can be characterized by calculating the linear stopping power. Carbon ions have a limited penetration depth within human tissues that depends on the energy and stopping power of these ions as they penetrate into the body. The purpose of the present study was to calculate the stopping power, range and dose to intestinal and prostate tissues of carbon ions. The stopping power values of these tissues were specified by the effective charge approach method. The 5ZaPa-NR-CV, pcemd-4 and pcSseg-4 sets of Gaussian-type functions were employed for the calculation of electronic charge density. Range calculations were made by means of the Gaussian quadrature method, making use of the continuous slowing down approximation. Flux-based dose calculations were also carried out in accordance with the Bragg-Gray theorem using the Geant4 and FLUKA simulation toolkits. The results were compared with each other and with the SRIM and CasP datasets. Then, depth-dose distributions and range values were verified by positron emission activity using the GATE toolkit. Among the different types of Gaussian functions used here, the best semi-analytical result was found for the 5ZaPa-NR-CV set. The results obtained in the present study can be used for dose verification and dose reconstruction in charged particle radiotherapy and for radiation research on the interaction of radiation with matter. The results calculated here will be useful for quantifying uncertainties associated with stopping power, range, and reconstruction of dose in charged particle therapy.
WO3 ince filmlerinin üretilmesi, yapısal ve elektriksel karakterizasyonu
(Hatay Mustafa Kemal Üniversitesi, 2010) Usta, Metin; Çetinkara, Ali
Bu çalışmada termal buharlaştırma yöntemiyle kuartz altlıklar üzerine WO3(ince film) nano yapılar elde edilmiş, film büyütme parametrelerinden biri olansıcaklığın, üretim sonrası tavlama işleminin üretilen filmlerin morfolojisi, kristalografikyapısı ve elektriksel özellikleri üzerine etkisi araştırılmıştır.

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