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Öğe Calculations of neutron-induced production cross-sections of W-180,W-182,W-183,W-184,W-186 up to 20 MeV(Pergamon-Elsevier Science Ltd, 2009) Sarer, Başar; Aydın, Abdullah; Günay, Mehtap; Korkmaz, Mustafa E.; Tel, EyyüpNeutron-induced cross-sections for the stable isotopes W-180,W-182,W-183,W-184,W-186 in the energy region up to 20 MeV have been calculated. Calculations were made with the codes CEM03.01 and ALICE/ASH, using the following models: the Dubna version of the intranuclear cascade model for the cascade stage of interaction; the hybrid, the geometry dependent hybrid and the exciton model for the pre-equilibrium component; the Hauser-Feshbach and the Weisskopf-Ewing statistical models for the equilibrium component. Effects of some important model parameters such as level density parameter and pairing correction were investigated. Calculated cross-sections were compared with available experimental data in the literature and with ENDF/B-VI T = 300 K and JENDL-3.3 T = 300 K evaluated data libraries. (C) 2008 Elsevier Ltd. All rights reserved.Öğe Calculations of the main free path on neutron emission cross-section for spallation reaction of target and fuel nuclei(2007) Tel, Eyyüp; Kişoğlu, H.Fatih; Topaksu, A.Kayış; Aydın, Abdullah; Kaplan, AbdullahThere are several new technological application fields of fast neutrons such as accelerator-driven incineration/ transmutation of the long-lived radioactive nuclear wastes (in particular transuranium nuclides) to short-lived or stable isotopes by secondary spallation neutrons produced by high-intensity, intermediate-energy, charged-particle beams, prolonged planstary space missions, shielding for particle accelerators. Especially, accelerator driven subcritical systems (ADS) can be used for fission energy production and /or nuclear waste transmutation as well as in the intermediate-energy accelerator driven neutron sources, ions and neutrons with energies beyond 20 MeV, the upper limit of exiting data files that produced for fusion and fission applications. In these systems, the neutron scattering cross sections and emission differential data are very important for reactor neutronics calculations. The transition rate calculation involves the introduction of the parameter of mean free path determines the mean free path of the nucleon in the nuclear matter. This parameter allows an increase in mean free path, with simulation of effect, which is not considered in the calculations, such as conservation of parity and angular momentum in intra nuclear transitions. In this study, we have investigated the multiple pre-equilibrium matrix element constant from internal transition for Uranium, Thorium, (n,xn) neutron emission spectra. The neutron-emission spectra produced by (n,xn) reactions on nuclei of some target (for spallation) have been calculated. In the calculations, we have used the geometry dependent hybrid model and the cascade exciton model including the effects of the pre-equilibrium. The pre-equilibrium direct effects have been examined by using full exciton model. All calculated results have been compared with the experimental data. The obtained results have been discussed and compared with the available experimental data and found agreement with each other.Öğe Equilibrium and pre-equilibrium calculations of neutron production in medium-heavy targets irradiated by protons up to 100 MeV(Pergamon-Elsevier Science Ltd, 2008) Aydin, Emine Gamze; Tel, Eyyüp; Kaplan, Abdullah; Aydın, AbdullahIn this study, by using equilibrium and pre-equilibrium reaction mechanisms, the (p,xn) cross-sections of the spallation neutron target nuclei Cr-50,Cr-52,Cr-53,Cr-54 and Cu-63,Cu-65 were investigated for incident proton energies up to 100 MeV. The excitation functions for pre-equilibrium reaction mechanisms were calculated by using a hybrid model, a geometry dependent hybrid model, the full exciton model and the cascade exciton model. Equilibrium effects were calculated according to the Weisskopf-Ewing model. The calculation results were also compared with the measurements in literature. (c) 2008 Elsevier Ltd. All rights reserved.Öğe The equilibrium and preequilibrium neutron-emission spectra of some structural fusion materials for (n, xn) reactions up to 16 MeV energy(Maik Nauka/Interperiodica/Springer, 2009) Kaplan, Abdullah; Tel, Eyyüp; Aydin, AbdullahIn this study, neutron-emission spectra produced by (n, xn) reactions for some structural fusion materials as (27)Al, (51)V, (52)Cr, (55)Mn, and (56)Fe have been investigated by a neutron beam up to 16 MeV. Multiple preequilibrium mean-free-path constant from internal transition and the preequilibrium and equilibrium level-density parameters have been investigated for some (n, xn) neutron-emission spectra calculated in this study. Preequilibrium neutron-emission spectra were calculated by using new-evaluated hybrid model and geometry-dependent hybrid model, full-exciton model, and cascade-exciton model. The reaction equilibrium component was 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 Investigation of coulomb and pairing effects using new developed empirical formulas for proton-induced reaction cross sections(Maik Nauka/Interperiodica/Springer, 2010) Tel, Eyyüp; Aydın, E. Gamze; Aydın, Abdullah; Kaplan, Abdullah; Bölükdemir, Mustafa Hicabi; Okuducu, ŞerefWe have investigated Coulomb and pairing effects by using new empirical formulas including the new coefficients for (p, alpha) at 17.9 MeV, (p, np) at 22.3 MeV, and (p, n alpha) at 24.8 and 28.5 MeV energies. A new formula is obtained by adjusting Levkovskii's original asymmetry parameter formula and also Tel et al. formula for proton-induced reactions. The new coefficients by using least-squares fitting method for the reactions are determined. In addition, the findings of the present study are compared with the available experimental data.Öğe Investigation of excitation functions using new evaluated empirical and semi-empirical systematic for 14-15 MEV (n,t) reaction cross sections(2007) Tel, Eyyüp; Aydın, Abdullah; Aydin, Emine G.; Kaplan, AbdullahThe hybrid reactor is a combination of the fusion and fission processes. In the fusion-fission 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 is 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 the 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 section 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 formulas by fitting two parameter for (n,t) reactions were given. All calculated results have been compared with the experimental data. By using the new cross sections formulas (n,t) reactions the obtained results have been discussed and compared with the available experimental data.Öğe Investigation of the nuclear structure of the Be, Cr and Cu isotopes(Pergamon-Elsevier Science Ltd, 2009) Tel, Eyyüp; Baldık, Rıdvan; Aytekin, Hüseyin; Aydin, AbdullahThe Root-Mean-Square (RMS) nuclear charge, neutron and proton radii, charge, neutron and proton densities, neutron skin thickness and total binding energy per particle were calculated using the Hartree-Fock method with Skyrme forces for the chromium (Cr), copper (Cu) and beryllium (Be) isotopes. The obtained results were compared with the experiment. Additional to these calculations the initial neutron and proton exciton numbers for Cr-52 isotope were also calculated. These exciton numbers can be used for pre-equilibrium proton induced (p, xn) reactions on Cr-52 isotope. (C) 2009 Elsevier Ltd. All rights reserved.Öğe Investigation of the properties of the nuclei used on the new generation reactor technology systems (Conference Paper)(2007) Tel, Eyyüp; Şahin, Hacı Mehmet; Yalçin Ş.; Altinok T.; Kaplan, Abdullah; Aydın, AbdullahThe application fields of the fast neutron are Accelerator-Driven subcritical Systems (ADS) for fission energy production and hybrid reactor systems. The technical design hybrid reactor and ADS systems potentialities require the knowledge of a wide range of better data and much effort. Thorium (Th) and Uranium (U) are nuclear fuels in these reactor systems. Lead (Pb), Bismuth (Bi) and Tungsten (IT) are the target nuclei in the ADS reactor systems. The Hartree-Fock (H-F) method with an effective interaction with Skyrme forces is widely used for studying the properties of nuclei such as binding energy, Root Mean Square (RMS) charge radii, mass radii, neutron density, proton density, electromagnetic multipole moments, etc. In this study, by using H-F method with interaction Skyrme RMS charge radii, RMS mass radii, neutron density and proton density were calculated for the 232Th, 238U, 207Pb, 209Bi and 184W isotopes used on the new generation reactor systems. The calculation results of charge radii have been compared with experimental data and obtained other results have been discussed for hybrid and ADS reactor systems.Öğe A new formulae study for the (n,2p) reaction cross-section systematics at 14-15 MeV(PERGAMON-ELSEVIER SCIENCE LTD, 2020) Kavun, Yusuf; Aydin, Abdullah; Tel, EyyüpThe cross-section calculation systematics for nuclear reactions have great importance in describing the particleinduced excitation of nuclei. In this study, for 14-15 MeV of incident neutron energy, it has been suggested new empirical formulae to describe the (n, 2p) reactions cross sections. The new empirical formulae have been obtained for 29 <= A <= 159, 29 <= A <= 103 and 133Öğe Newly developed semi-empirical formulas for (p, α) at 17.9 MeV and (p, np) at 22.3 MeV reaction cross-sections(Indian Acad Sciences, 2010) Tel, Eyyüp; Aydın, Abdullah; Aydın, E. Gamze; Kaplan, Abdullah; Yavaş, Ömer; Reyhancan, İskender A.In this study, we have investigated the asymmetry term effect for the (p, alpha) and (p, np) reaction cross-sections and obtained new coefficients for the (p, alpha) and (p, np) reaction cross-sections at 17.9 and 22.3 MeV energies. We have suggested semi-empirical formulas including the non-elastic effects of optical model found by fitting two parameters for proton-induced reactions. The coefficients were determined by least-square fitting method. The obtained cross-section formulas with new coefficients have been discussed and compared with the available experimental data.Öğe Production cross sections of medical In-110,In-111 radionuclides(Carl Hanser Verlag, 2010) Büyükuslu, Halim; Kaplan, Abdullah; Yıldırım, Gürcan; Aydin, Abdullah; Tel, Eyyüp; Bölükdemir, Mustafa HicabiIn this study, production routes of medical In-110,In-111 radio-nuclides produced by Cd-110(p, n)In-110, Cd-111(p, 2n)In-110, (112)cd(p, 3n)In-110, Ag-107(alpha, n)In-110, Ag-109(alpha, 3n)In-110, Cd-111(p, n)In-111, Cd-112(p, 2n)In-111, Cd-113(p, 3n)In-111, Cd-114(p, 4n)In-111, Ag-109(alpha, 2n)In-111, Ag-107(alpha, gamma)In-111 and In-113(n, 3n)In-111 reactions have been investigated up to 70 MeV incident particle energy. In these calculations, the pre-equilibrium and equilibrium effects have been investigated. The pre-equilibrium calculations involve the geometry dependent hybrid model and the cascade exciton model. The full exciton model has also been used to investigate the pre-equilibrium direct effects. Equilibrium effects are calculated according to the Weisskopf-Ewing model. The calculated results are compared with the experimental data taken from the literature.Öğe Theoretical cross sections of Bi-209, Th-232, U-235 and U-238 on deuteron-induced reactions(Pergamon-Elsevier Science Ltd, 2010) Büyükuslu, Halim; Kaplan, Adullah; Tel, Eyyüp; Aydin, Abdullah; Yıldırım, Gürcan; Bolükdemir, Mustafa HicabiThere are many application fields for fast neutrons. The main application fields of the fast neutrons are accelerator-driven sub-critical systems (ADS) and fusion-fission (hybrid) reactor systems for fission energy production. Thorium (Th) and uranium (U) are nuclear fuels in fusion-fission (hybrid) reactor systems and bismuth (Bi) is also the target nucleus in the ADS reactor systems. In this study, neutron production cross sections produced by (d, xn) reactions for spallation targets such as Bi-209, Th-232, U-235 and U-238 have been investigated. New evaluated hybrid model and geometry dependent hybrid model have been used to calculate the pre-equilibrium neutron production cross sections. For the reaction equilibrium component, Weisskopf-Ewing model calculations have been preferred. The obtained results have been discussed and compared with the available experimental data and found in agreement with each other. (C) 2010 Elsevier Ltd. All rights reserved.
