Yazar "Kaplan, A." seçeneğine göre listele
Listeleniyor 1 - 20 / 25
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe (3He,xn) Reaction Cross-Section Calculations for the StructuralFusion Material 181Ta in the Energy Range of 14–75 MeV(Springer, 2014) Kaplan, A.; Capali, V.; Ozdogan, H.; Aydin, A.; Tel, E.; Sarpun, I. H.The theoretical neutron-production cross-sections produced by Ta-181(He-3,xn)Re184-x reactions (x = 1-7) for structural fusion material Ta-181 in He-3-induced reactions have been performed in the incident He-3 energy range of 14-75 MeV. Reaction cross-sections, based on theoretical pre-equilibrium nuclear reaction models, have been calculated theoretically by means of the TALYS 1.6 two component exciton, EMPIRE 3.1 exciton, ALICE/ASH geometry dependent hybrid (GDH) and ALICE/ASH hybrid models. The neutron-production cross-section results of the models have been compared with the each other and against the experimental nuclear reaction data (EXFOR). Except the Ta-181(He-3,2n)Re-182 and Ta-181(He-3,7n)Re-177 reactions, the ALICE/ASH cross-section calculations show generally agreement with the experimental values for all reactions used in this study. The ALICE/ASH-GDH model can be suggested, if the experimental data are unavailable or are improbably to be produced because of the experimental troubles.Öğe Calculation of 14-15 MeV (n, d) reaction cross sections using newly evaluated empirical and semi-empirical systematics(Springer, 2008) Aydin, A.; Tel, E.; Kaplan, A.In this study, we have investigated the asymmetry term effect for the (n, d) reaction cross sections at 14-15 neutron incident energy. It has been discussed the odd-even effect and the pairing effect considering binding energy systematic of the nuclear shell model for the new experimental data and new cross section formulae developed by Tel et al. for (n, d) reactions. We have determined different parameter groups by the classification of nuclei into even-even, even-odd and odd-even for (n, d) reactions cross sections. The obtained empirical and semi-empirical formulae by fitting two parameters for (n, d) reactions were given. By using the new cross sections formulae for (n, d) reactions the obtained results have been discussed and compared with the available experimental data.Öğe Calculations of Double Differential Deuteron Emission Cross Sections at 62 MeV Proton Induced Reactions(Springer, 2013) Aydin, A.; Sarpun, I. H.; Kaplan, A.; Tel, E.In this study, double differential deuteron emission cross sections for Al-27, Fe-54,Fe-56, Au-197, Pb-208 and Bi-209 target nuclei have been calculated by the TALYS code at 62 MeV proton energy. The use of TALYS involved calculations by the pre-equilibrium exciton model and the Hauser-Feshbach model. The calculated double differential cross sections have been compared with the experimental data taken from the literature.Öğe Calculations of Double-Differential Neutron Emission Cross Sections for Be-9 Target Nucleus at 14.2 MeV Neutron Energy(Springer, 2015) Sahan, M.; Tel, E.; Sahan, H.; Kara, A.; Aydin, A.; Kaplan, A.; Yildiz, E.In this study, we investigated neutron-emission spectra induced by (n,xn) nuclear reactions for the Be-9 structural fusion material at 14.2 MeV neutron energy. We calculated double-differential cross sections () with ALICE-2011 codeor the angles of 30A degrees, 60A degrees, 90A degrees, 120A degrees, and 150A degrees. Hybrid Monte Carlo simulation model have been used to calculate the double differential emission spectra for these different angles. The obtained results were compared with the measured data taken from EXFOR library. The results show an acceptable agreement.Öğe Calculations of double-differential triton emission cross sections at 62-MeV proton-induced reactions(Pleiades Publishing Inc, 2014) Aydin, A.; Sarpun, I. H.; Kaplan, A.Double-differential cross sections (d (2) sigma/d Omega dE >) have been calculated and analyzed for triton production in proton-induced reactions on Al-27, Fe-54,Fe-56, Au-197, and Pb-208 target nuclei at incident energy of 62 MeV. Calculations of double-differential cross sections have been performed using nuclear models implemented in the TALYS 1.2 code. The calculated results of the double-differential cross sections for triton emission have been compared with the existing experimental data.Öğe Comparison of Level Density Models for the Ni-60,Ni-61,Ni-62,Ni-64(p, n) Reactions of Structural Fusion Material Nickel from Threshold to 30 MeV(Springer, 2015) Aydin, A.; Pekdogan, H.; Kaplan, A.; Sarpun, I. H.; Tel, E.; Demir, B.The knowledge of level density for reaction cross-section calculations are needed for various applications such as fission and fusion reactor design, accelerator driven sub-critical systems, nuclear medicine, neutron capture and astrophysics. In this study, the excitation functions for (p, n) reactions from reaction threshold to 30 MeV proton incident energy on Ni-60, Ni-61, Ni-62 and Ni-64 isotopes were calculated using TALYS 1.6 nuclear code involving the level density models. This is of importance to the validation of nuclear model approaches with increased predictive power. There are several models of level density that can be used to predict cross-section. In this work, the (p, n) cross-sections would be calculated using three different model of level density, such as constant temperature model, back-shifted fermi gas model and generalized superfluid model on Ni-60,Ni-61,Ni-62,Ni-64 reactions. The (p, n) reaction cross-section calculations for Ni-60,Ni-61,Ni-62,Ni-64 target nuclei were compared with each other and the experimental nuclear reaction data obtained from EXFOR database.Öğe Double Differential Cross Section and Stopping Power Calculations of Light Charged Particle Emission for the Structural Fusion Materials Cr-50,Cr-52(Springer, 2015) Demir, B.; Sarpun, I. H.; Kaplan, A.; Capali, V.; Aydin, A.; Tel, E.Double differential cross section is a fundamental value to determine nuclear heating and material damages in structural fusion material research. In this study, double differential light charged particle emission cross sections for Cr-50,Cr-52 target nuclei have been calculated by the TALYS 1.6 code at 14.8 MeV incident neutron energy. Penetrating distance and stopping powers have been calculated for the alpha, deuteron and proton particles, taking into consideration all possible reactions in Cr-50,Cr-52 for incident energies of 0.5-22.2 MeV using GEANT4 calculation code. The compound nucleus formation process dominates the emission of proton and alpha particles. Direct reaction contribution becomes dominant in higher particle emission energies. The calculated double differential cross sections have been compared with the available experimental data taken from the literature.Öğe The effect of the initial exciton numbers on Fe-54,Fe-56(p, xp) Pre-Equilibrium Reactions(Maik Nauka/Interperiodica/Springer, 2011) Bolukdemir, M. H.; Tel, E.; Aydin, A.; Okuducu, S.; Kaplan, A.In pre-equilibrium nuclear reactions, the geometry-dependent hybrid model is applied with the use of the neutron and proton densities to investigate the effect of initial exciton numbers on the nucleon emission spectra. The initial exciton numbers calculated with the theoretical neutron and proton densities have been obtained within the Skryme-Hartree-Fock method with SKM* and SLy4 forces on target nuclei in the Fe-54,Fe-56(p, xp) reaction at 61.5-MeV incident proton energy by using a new calculationmethod of Tel et al. Also, the differences between the initial exciton numbers for protons and neutrons as a function of nuclear radius, focusing on systematic discrepancies correlated to differences in the proton and neutron densities have been investigated.Öğe Excitation Functions of Some Neutron Production Targets on (d,2n) Reactions(Springer, 2010) Kaplan, A.; Buyukuslu, H.; Aydin, A.; Tel, E.; Yildirim, G.; Bolukdemir, M. H.Deuterons are weakly bound nuclei which easily undergo break up reactions. This is well known at low energies, around 10 MeV, where deuteron beams have been used to produce neutrons very efficiently. These neutrons have a widely application field such as fission energy production and hybrid reactor systems. In this study, neutron emission cross sections produced by (d,2n) reactions for spallation neutron targets such as Cr-52, Fe-56, Ni-60,Ni-62,Ni-64, Cu-63,Cu-65, W-182,W-183,W-184,W-186, Th-232, U-235 and U-238 have been investigated. Hybrid model and geometry dependent hybrid model were used to calculate the pre-equilibrium neutron-emission cross sections. For the reaction equilibrium process, Weisskopf-Ewing model calculations were selected. The obtained results have been discussed and compared with the available experimental data and found agreement with each other.Öğe Investigation of 14-15 MeV (n, t) reaction cross-sections by using new evaluated empirical and semi-empirical systematic formulas(Springer, 2008) Tel, E.; Aydin, A.; Kaplan, A.; Sarer, B.In the hybrid reactor, tritium self-sufficiency must be maintained for a commercial power plant. For self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. Working out the systematics of (n, t) reaction cross-sections are of great importance for the definition of the excitation function character for the given reaction taking place on various nuclei at energies up to 20 MeV. In this study we have investigated asymmetry term effect for the (n, t) reaction cross-sections at 14-15 neutron incident energy. It has been discussed the odd-even effect and the pairing effect considering binding energy systematic of the nuclear shell model for the new experimental data and new cross-sections formulas (n, t) reactions developed by Tel et al. We have determined a different parameter groups by the classification of nuclei into even-even, even-odd and odd-even for (n, t) reactions cross-sections. The obtained empirical and semi-empirical formulas by fitting two parameter for (n, t) reactions were given. All calculated results have been compared with the experimental data and the other semi-empirical formulas.Öğe Investigation of neutron skin effect with density dependence by using a new calculation method for initial exciton numbers on pre-equilibrium reactions(Iop Publishing Ltd, 2009) Tel, E.; Bolukdemir, M. H.; Okuducu, S.; Aydin, A.; Kaplan, A.In this study, we investigated the pre-equilibrium effect by using a new evaluated geometry-dependent hybrid model and a neutron skin effect with density dependence for the (204,206,207)Pb(p, xn) reaction at 25.5MeV incident proton energy. We calculated the initial exciton numbers obtained from the modified Skyrme force based on fitting the fission barriers of heavy deformed nuclei (SKM*) and SLy4 for proton induced reaction on target nuclei (204,206,207)Pb. We calculated, by using a new calculation method, the initial neutron and proton exciton numbers for (204,206,207)Pb from the neutron and proton density and we investigated the shell effect by using an effective nucleon-nucleon interaction with Skyrme force. We also compared the geometry-dependent hybrid model (GDH), newly evaluated with the initial exciton number calculations of the neutron emission spectra of the (204,206,207)Pb(p, xn) reaction, with the values reported in the literature at 25.5MeV incident proton energy. The obtained results were investigated and compared with the pre-equilibrium calculations and experimental results.Öğe Investigation of the neutron emission spectra of some deformed nuclei for (n,xn) reactions up to 26 MeV energy(Indian Assoc Cultivation Science, 2011) Kaplan, A.; Buyukuslu, H.; Tel, E.; Aydin, A.; Bolukdemir, M. H.In this study, neutron-emission spectra produced by (n,xn) reactions up to 26 MeV for some deformed target nuclei as (165)Ho, (181)Ta, (184)W, (232)Th and (238)U have been investigated. Also, the mean free path parameter's effect for (n,xn) neutron-emission spectra has been examined. In the calculations, pre-equilibrium neutron-emission spectra have been calculated by using new evaluated hybrid model and geometry dependent hybrid model, full exciton model and cascade exciton model. The reaction equilibrium component has been calculated by Weisskopf-Ewing model. The obtained results have been discussed and compared with the available experimental data and found agreement with each other.Öğe Neutron Emission Spectra of 104,105,106,108,110Pd Isotopes for (p,xn) Reactions at 21.6 MeV Proton Incident Energy(Springer, 2010) Buyukuslu, H.; Kaplan, A.; Tel, E.; Aydin, A.; Yildirim, G.Palladium, which is a rare and lustrous silvery-white color from precious metals, plays important role in fusion-fission reactions and different fields of nuclear technology. In addition, it is used for not only cold fusion experiments but also separation of hydrogen isotopes researches for fusion reactors. In this study, neutron-emission spectra produced by (p,xn) reactions for structural fusion material 104,105,106,108,110Pd isotopes have been investigated by a proton beam at 21.6 MeV. Moreover, multiple pre-equilibrium mean free paths constant from internal transition, and the pre-equilibrium and equilibrium level density parameters have been analyzed for some (p,xn) neutron-emission spectra calculated. New evaluated hybrid model and geometry dependent hybrid model, full exciton model and cascade exciton model were used to calculate the pre-equilibrium neutron-emission spectra. For the reaction equilibrium component, Weisskopf-Ewing model calculations were preferred. The obtained results have been discussed and compared with the available experimental data and found agreement with each other.Öğe Neutron Production Cross-Section and Geant4 Calculations of the Structural Fusion Material Co-59 for (alpha,xn) and (gamma,xn) Reactions(Springer, 2015) Demir, B.; Kaplan, A.; Capali, V.; Ozdogan, H.; Sarpun, I. H.; Aydin, A.; Tel, E.Recent advances in technology and computer sciences give us simplicity to investigate phenomena of nuclear physics. Scientists have improved various nuclear reaction codes such as Talys, Alice/ASH, Cem95, Empire, Geant4 and Fluka. These programs give us chance to calculate crucial quantity like reaction cross-section, energy spectrum of out-going particles, stopping power and penetrating distances in target material. The stopping power of alpha in Co-59 material is acquired as it has helpful applications of shielding and choosing the proper thickness of the target. Evaluation of the reaction cross-section data is very important to various applications such as improvement structural material, reactor design and radioisotopes production. In this study, we calculated the neutron production cross-sections of Co-59 using TALYS 1.6 and EMPIRE 3.1 codes for different level density models. Penetrating distances and stopping powers have been calculated for the alpha particles taking into consideration all possible reactions in Co-59 using GEANT4 simulation program. The obtained (alpha,xn) and (gamma,xn) reactions (x = 1, 2, 3) cross-section values have been compared with the each other and against the experimental nuclear reaction data existing in EXFOR database.Öğe New calculation method for initial exciton numbers on nucleon induced pre-equilibrium reactions(Amer Physical Soc, 2008) Tel, E.; Aydin, A.; Kaplan, A.; Sarer, B.In this study, we investigate the pre-equilibrium effect by using new evaluated geometry dependent hybrid model for the 208 Ph (p, xn) reaction at 25.5 and 62.9 MeV incident proton energies. We also suggest that the initial neutron and proton exciton numbers for the nucleon induced precompound reactions be calculated from the neutron and proton density by using an effective nucleon-nucleon interaction with Skyrme force. We calculate the initial exciton numbers obtained from SKM* and SLy4 for a proton induced reaction on target nuclei 208 Ph. The obtained results have been investigated and compared with the pre-equilibrium calculations and experimental results.Öğe New calculations of excitation functions of some positron emitting and single photon emitting radioisotopes(Carl Hanser Verlag, 2008) Aydin, E. G.; Tel, E.; Kaplan, A.; Aydin, A.In this study, new calculations of the excitation functions of (56)Fe(p,2n)(55)Co, (58)Fe(p,2n)(57)Co, (60)Ni(pn)(60)Ca, (62)Ni(p,2n)(61)Cu, (68)Zn (p,2n)(67)Ga, (72)Ge(p,n)(72)As, (82)Kr(p,2n)(81)Rb, (124)Xe(p,2n)(123)Cs, (112)Cd(p,2n)(111)In and (203)Tl(p,3n)(201)Pb reactions have been carried for incident proton energies up to 50 MeV. In these calculations, the pre-equilibrium and equilibrium effects have been investigated. The pre-equilibrium calculations involve the newly evaluated geometry-dependent hybrid model, hybrid model and the cascade exciton model. Equilibrium effects are calculated according to the Weisskopf-Ewing model. The calculated results tire compared with the experimental data taken from the literature.Öğe A New Comparison of Empirical and Semi-empirical Formulae for the (n, 3He) Reaction Cross-sections at 14–15 MeV(Springer, 2008) Aydin, A.; Tel, E.; Sarer, B.; Kaplan, A.New empirical and semi-empirical formulae have been suggested for the (n, He-3) reaction cross-sections with dependent on asymmetry parameter, S = (N - Z)/A. The (n, He-3) reaction cross-sections at the energy of 14-15 MeV have been investigated for two different parameters groups by the classification of nuclei into 31 <= A <= 103 and 133 <= A <= 181. The obtained results have been compared with the other systematics and experimental data for the (n, He-3) reaction cross-sections. Some improvement has been got in describing the (n, He-3) reaction cross-sections compared with the existing relations.Öğe New Evaluated Semi-Empirical Formula Using Optical Model for 14-15 MeV (n, t) Reaction Cross Sections(Springer, 2009) Tel, E.; Durgu, C.; Aydin, A.; Boeluekdemir, M. H.; Kaplan, A.; Okuducu, S.In the next century the world will face the need for new energy sources. Nuclear fusion can be one of the most attractive sources of energy from the viewpoint of safety and minimal environmental impact. Fusion will not produce CO2 or SO2 and thus will not contribute to global warming or acid rain. Achieving acceptable performance for a fusion power system in the areas of economics, safety and environmental acceptability, is critically dependent on performance of the blanket and diverter systems which are the primary heat recovery, plasma purification, and tritium breeding systems. Tritium self-sufficiency must be maintained for a commercial power plant. The hybrid reactor is a combination of the fusion and fission processes. For self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. So working out the systematics of (n, t) reaction cross-sections are of great importance for the definition of the excitation function character for the given reaction taking place on various nuclei at energies up to 20 MeV. In this study, we have calculated non-elastic cross-sections by using optical model for (n, t) reactions at 14-15 MeV energy. We have investigated the excitation function character and reaction Q-values depending on the asymmetry term effect for the (n, t) reaction cross-sections. We have obtained new coefficients for the (n, t) reaction cross-sections. We have suggested semi-empirical formulas including optical model nonelastic effects by fitting two parameters for the (n, t) reaction cross-sections at 14-15 MeV. We have discussed the odd-even effect and the pairing effect considering binding energy systematic of the nuclear shell model for the new experimental data and new cross-sections formulas (n, t) reactions developed by Tel et al. We have determined a different parameter groups by the classification of nuclei into even-even, even-odd and odd-even for (n, t) reactions cross-sections. The obtained cross-section formulas with new coefficients have been discussed and compared with the available experimental data.Öğe Photo-neutron Cross Section Calculations of Several Structural Fusion Materials(Springer, 2013) Kaplan, A.; Ozdogan, H.; Aydin, A.; Tel, E.In this study, the theoretical photo-neutron cross-sections produced by (gamma,n) reactions for several structural fusion materials such as V-51, Mn-55, Ni-58, Zr-90,Zr-91,Zr-92,Zr-94, and Ta-181 have been investigated in the incident energy range of 7-40 MeV. Reaction cross-sections as a function of photon energy have been calculated theoretically using the PCROSS and TALYS 1.2 computer codes. TALYS 1.2 default and pre-equilibrium models have been used to calculate the pre-equilibrium photo-neutron cross-sections. For the reaction equilibrium component, PCROSS Weisskopf-Ewing model calculations have been preferred. The calculated results have been compared with each other and against the experimental data in the existing databases EXFOR and TENDL-2011. PCROSS Weisskopf-Ewing model calculations show a similar structure with experimental data but they are higher than the experimental values for all reactions except for Zr-90(gamma,n)Zr-89 reaction. Generally, TALYS 1.2 default and pre-equilibrium model cross-section calculations are the best agreement with the experimental data for all reactions except for Ni-58(gamma,n)Ni-57 reaction along the incident photon energy in this study. The TALYS 1.2 curves fit the TENDL-2011 data the best. If photo-neutron cross-section data is needed for an isotope where there is no experimental data available for comparison, TALYS 1.2 pre-equilibrium option has been recommended.Öğe Photo-neutron cross-section calculations of 142,143,144,145,146,150Nd rare-earth isotopes for (γ, n) reaction(Pleiades Publishing Inc, 2014) Kaplan, A.; Ozdogan, H.; Aydin, A.; Tel, E.The theoretical photo-neutron cross sections for (gamma, n) reaction have been calculated on 142,143,144,145,146,150Nd rare-earth isotopes at photon energies of 8-23 MeV using the PCROSS, TALYS 1.2, and EMPIRE 3.1 computer codes. TALYS 1.2 two-component exciton model and EMPIRE 3.1 exciton model has been used to calculate the pre-equilibrium photo-neutron cross sections. PCROSS Weisskopf-Ewing model has been used for the reaction equilibrium cross-section calculations. The obtained cross sections have been compared with each other and against the experimental values existing in the EXFOR database. Generally, pre-equilibrium model cross-section calculations are in good agreement with the experimental data for all reactions along the incident photon energy in this study.
