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Öğe Application of asymmetry depending empirical formulas for (p,nα) reaction cross-sections at 24.8 and 28.5 MeV incident energies(Pergamon-Elsevier Science Ltd, 2009) Tel, Eyüp; Aydın, Emine Gamze; Aydın, Abdullah; Kaplan, AbdullahIn this study, we have investigated the asymmetry term effect for the (p,n alpha) reaction cross-sections and we have obtained new coefficients for the (p,n alpha) reactions at 24.8 and 28.5 MeV energies. We have suggested empirical formulas including the new coefficients found by fitting two parameters for proton induced reactions. The coefficients were determined by least-squares fitting method. The obtained cross-section formulas with new coefficients have been discussed and compared with the available experimental data. (C) 2008 Elsevier Ltd. All rights reserved.Öğe Application of the luminescence single-aliquot technique for dose estimation in the Marmara Sea(Elsevier Sci Ltd, 2005) Tanır, Güneş; Şencan, Emine; Bölükdemir, M. Hicabi; Türköz, Mustafa Burak; Tel, EyüpThe aim of this study is to obtain the equivalent dose, which is the important quantity for all the studies related to the use of luminescence in dating sediments. Recent advances in luminescence dating have led to increasing application of the technique to sediment from the depositional environmental samples. The sample used in this study is the active main fault sample that was collected from the Sea of Marmara in NW Turkey. Equivalent dose was measured using both the multiple-aliquots and the single-aliquot techniques. In this study single aliquot regeneration on additive dose (SARA) procedure was also used. The result obtained was not in agreement with the results evaluated from the multiple-aliquots procedure. So a simple modification was suggested for SARA. procedure. In our modified procedure the calculated dose (D) values were obtained by using the additive dose protocol instead of regeneration protocol. (c) 2005 Elsevier Ltd. All rights reserved.Öğe Calculation of Proton Total Reaction Cross Sections for Some Target Nuclei in Incident Energy Range of 10-600 MeV(Maik Nauka/Interperiodica/Springer, 2010) Büyükuslu, Halim; Kaplan, Abdullah; Aydın, Aduallah; Tel, Eyüp; Yıldırım, GürcanIn this study, proton total reaction cross sections have been investigated for some isotopes such as (12)C, (27)Al, (9)Be, (16)O, (181)Ta, (197)Au, (6)Li, and (14)N by a proton beam up to 600 MeV. Calculation of the proton total cross sections has been carried out by the analytic expression formulated by M.A. Alvi by using Coulomb-modified Glauber theory with the Helm model nuclear form factor. The obtained results have been discussed and compared with the available experimental data and found to be in agreement with each other.Öğe Comparison of the decay-rate parameter of the luminescence signal generated by various laboratory radiation doses(Springer, 2005) Tanır, Güneş; Türköz, Mustafa Burak; Şencan, Emine; Bölükdemir, M. Hicabi; Tel, Eyüp; Okuducu, ŞerefIn this work the parameter a representing the decay-rate of luminescence signal was investigated for two different samples, for luminescence dating purpose. The procedures of preheating/measurement and dose/preheating/measurement were repeatedly used for the natural and beta-irradiated forms of the samples at different infrared-stimulation time. Experimental data has shown that the IRSL signal decays in a way, which depends on the beta-dose given to the samples. This behavior is different from that observed by DULLER1 who did not find such dose-dependence.Öğe Determination of (n,2n) Reaction Cross Sections for Some Nuclei with Asymmetry Parameter(Springer, 2010) Sarpun, İsmail Hakkı; Yalim, Hüseyin Ali; Ünal, Rıdvan; Oruncak, Bekir; Aydin, Abdullah; Kaplan, Abdullah; Tel, EyüpThe (n,2n) reaction cross sections for targets of Tl-203,Tl-205, Pb-204,Pb-206,Pb-207,Pb-208, Bi-209, Th-232 and U-238 were calculated both theoretically and semi-empirically. Theoretical calculations were done using two different computer codes: PCROSS computer code for the full exciton model and ALICE/ASH-2006 computer code for the geometry dependent hybrid (GDH) model with the incident neutron energy up to 25 MeV. Semi-empirical calculations were done using formulas derived by several researchers. The obtained results have been discussed and compared with the available experimental data taken from the literature. The different nuclear reaction program codes used in the present study show considerable differences depending upon the selected energy range. Especially PCROSS calculation results show a disagreement above the incident energy of about 16 MeV for all the studied nuclei. Moreover, even though the graphs qualitatively agree in shape, they differ in magnitude below 15 MeV.Öğe Deuteron-Induced Cross Section Calculations of Some Structural Fusion Materials(Springer, 2013) Kaplan, Abdullah; Özdoğan, Hasan; Aydın, Abdullah; Tel, EyüpThe development of fusion materials for the safety of fusion power systems and understanding nuclear properties is important. The reaction cross-section data have a critical importance on fusion reactors and development for fusion reactor technology. In this study, the theoretical cross sections of some structural fusion materials such as Cr, V, Fe, Ni, Zr and Ta in deuteron-induced reactions have been investigated. The new calculations on the excitation functions of Cr-50(d, alpha)V-48, V-51(d, 2n)Cr-51, V-51(d, 4n)Cr-49, Fe-54(d, alpha)Mn-52, Fe-54(d, n)Co-55, Ni-58(d, alpha)Co-56, Zr-96(d, n)Nb-97, Zr-96(d, 2n)Nb-96 and Ta-181(d, 2n)W-181 reactions have been carried out up to 90 MeV incident deuteron energies. In these calculations, the pre-equilibrium and equilibrium effects have been investigated. The pre-equilibrium calculations involve the geometry dependent hybrid model and hybrid model. Equilibrium effects have been calculated according to the Weisskopf-Ewing model. The ALICE/ASH computer code has been used in all calculations. The calculated results have been compared with the experimental data existing in EXFOR database and found to be in good agreement.Öğe Double Differential Charged Particle Emission Cross Sections and Stopping Power Calculations for Structural Fusion Materials 58,60Ni(Springer, 2015) Sarpün, İsmail Hakkı; Aydin, Abdulah; Kaplan, Abdullah; Demir, Bayram; Tel, Eyüp; Çapalı, VeliIn this study, double differential light charged particle emission cross section, which is a fundamental data to determine nuclear heating and material damages in structural fusion material research, for Ni-58,Ni-60 target nuclei have been calculated by the TALYS 1.6 code at 14.8 MeV neutron incident energy and compared with available experimental data in EXFOR library. While the compound nucleus formation process contribution was found as dominant in the emission of proton and alpha particles, pre-equilibrium contribution was existed in the deuteron emission and the direct reaction contribution also was seen as dominant in higher particle emission energies. Penetrating distance and stopping powers also have been calculated for the alphas, deuterons and protons in Ni-58,Ni-60 using GEANT4 code and compared with previous works of Cr-50,Cr-52 and Ti-46,Ti-48.Öğe Equilibrium and pre-equilibrium emissions in proton-induced reactions on Tl-203,Tl-205(Indian Acad Sciences, 2009) Kaplan, Abdullah; Aydin, Abdullah; Tel, Eyüp; Sarer, BaşarIn this study, the excitation functions for the reactions Tl-203(p, n)Pb-203, Tl-205(p, 3n)Pb-203, Tl-203(p, 2n)Pb-202, Tl-205(p, 4n)Pb-202, Tl-203(p, 3n)Pb-201, Tl-205(p, 5n)Pb-201, Tl-203(p, 4n)Pb-200 and Tl-205(p, 6n)Pb-200 have been calculated using pre-equilibrium and equilibrium reaction mechanisms. Calculated results based on hybrid model, geometry-dependent hybrid model and cascade-exciton model have been compared with the experimental data.Öğe The Equilibrium and Pre-equilibrium Triton Emission Spectra of Some Target Nuclei for (n,xt) Reactions up to 45 MeV Energy(Springer, 2010) Tel, Eyüp; Kaplan, Abdullah; Aydin, Abdullah; Özkorucuklu, Suat; Büyükuslu, Halim; Yıldırım, GürcanAlthough there have been significant research and development studies on the inertial and magnetic fusion reactor technology, there is still a long way to go to penetrate commercial fusion reactors to the energy market. 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. So, working out the systematics of (n,t) reaction cross sections and triton emission differential data are important for the given reaction taking place on various nuclei at different energies. In this study, (n,xt) reactions for some target nuclei as (16)O, (27)Al, (59)Co and (209)Bi have been investigated up to 45 MeV incident neutron energy. In the calculations of the triton emission spectra, the pre-equilibrium and equilibrium effects have been used. The calculated results have been compared with the experimental data taken from the literature.Öğe Investigation of Deuteron Emission Spectra at 62 MeV Proton Incident Energy(Springer, 2010) Aydin, Abdullah; Türeci, Gökhan; Tel, Eyüp; Kaplan, AbdullahIn this study, deuteron emission cross sections for (27)Al, (54,56)Fe, (89)Y, (120)Sn, (197)Au, (208)Pb and (209)Bi target nuclei have been calculated at 62 MeV proton incident energy. In these calculations, the pre-equilibrium and equilibrium effects have been investigated. The pre-equilibrium calculations involve the geometry dependent hybrid model and hybrid model. Equilibrium effects are calculated according to the Weisskopf-Ewing model. The calculated results are compared with the experimental data taken from the literature and found to be in good agreement.Öğe Investigation of ground state features of some medical radionuclides(Carl Hanser Verlag, 2012) Tel, Eyüp; Aydın, Abdullah; Kara, Ayhan; Kaplan, AbdullahIn this study, ground state properties for some medical radionuclides used widely in medical applications have been investigated using Skyrme-Hartree-Fock (SHF) method. We calculated the proton, neutron and charge density RMS (root-mean-square) radii of some medical radionuclides such, as K-42 Ca-45, K-81, Rb-81, Rb-82, Sr-85, In-110, In-111, Cs-123, Tl-201 and (201)pb using the SHF calculations with the Skyrme force parameters. The calculated results are compared with the available experimental values for charge density RMS radii. The proton, neutron, charge and mass density distributions for all nuclei used in this study have also been calculated. The calculated conclusions can he used 'in estimating nuclear properties of the medical nuclei and for the calculations of pre-equilibrium reactions cross section data for the production of new medical radioisotopes.Öğe Investigation of the (n, p) reaction cross-sections of some nuclei in the rare-earth elements for an incident energy range of 8-24 MeV(Iop Publishing Ltd, 2007) Aydin, Abdullah; Tel, Eyüp; Sarer, BaşarIn this study, the (n, p) reaction cross-sections of some target nuclei in the rare-earth elements have been investigated for an incident energy range of 8 - 24 MeV. In these calculations, the geometry-dependent hybrid model and the cascade exciton model including the effects of pre-equilibrium have been used. The full exciton model has also been used to investigate the pre-equilibrium direct effects. All calculated results have been compared with experimental data. In addition, the ratios of experimental ( n, p) cross-sections to calculated cross-sections using empirical and semi-empirical formulae have been calculated.Öğe Neutron Emission Spectra of Some Structural Fusion Materials at 26.8 and 45.2 MeV Alpha Incident Energies(Springer, 2010) Kaplan, Abdullah; Aydin, Abdullah; Tel, Eyüp; Büyükuslu, HalimIn this study, neutron-emission spectra produced by (alpha,xn) reactions for some structural fusion materials such as Al-27, Cr-53, Fe-56 and Ni-58,Ni-60,Ni-62 have been investigated. Hybrid model, geometry dependent hybrid model and full exciton model have been used to calculate the pre-equilibrium neutron-emission spectra. For the reaction equilibrium component, Weisskopf-Ewing model calculations have been preferred. The mean free path parameter's effect for (alpha,xn) neutron-emission spectra has been examined. The obtained results have been discussed and compared with the available experimental data and found agreement with each other.Öğe New calculations of cyclotron production cross sections of some positron emitting radioisotopes in proton induced reactions(Indian Assoc Cultivation Science, 2009) Tel, Eyüp; Aydın, Emine Gamze; Kaplan, Abdullah; Aydın, AbdullahIn this study, new calculations on the excitation functions of C-13(p,n)N-13, N-14(p,alpha)C-11, N-15(p,n)O-15, O-16(p,alpha)N-13, O-18(p,n)F-18, Ni-62(p,n)Cu-62, Zn-68(p,n)Ga-68 and Ge-72(p,n)As-72 reactions have been carried out in the 5-40 MeV incident proton energy range. In these calculations, the pre-equilibrium and equilibrium effects have been investigated. The pre-equilibrium calculations involve hybrid model, geometry dependent hybrid model, the cascade exciton model and full exciton model. Equilibrium effects were calculated according to Weisskopf-Ewing model. The calculated results have been compared with experimental data taken from literature.Öğe New empirical formula for calculating (n, p) reaction cross-sections at 14.5 MeV neutrons(WORLD SCIENTIFIC PUBL CO PTE LTD, 2020) Akrawy, Dashty T.; Ahmed, Ali H.; Tel, Eyüp; Aydın, Abdullah; Sihver, L.An empirical formula to calculate the (n, p) reaction cross-sections for 14.5 MeV neutrons for 183 target nuclei in the range 44 <= A <= 212 is presented. Evaluated cross-section data from TENDL nuclear data library were used to test and benchmark the formula. In this new formula, the nonelastic cross-section term is replaced by the atomic number Z, while the asymmetry parameter-dependent exponential term has been retained. The calculated results are presented in comparison with the seven previously published formulae. We show that the new formula is significantly in better agreement with the measured values compared to previously published formulae.Öğe Nuclear model calculations on the production of 125,123Xe and 133,131,129,128Ba radioisotopes(Maik Nauka/Interperiodica/Springer, 2012) Aydin, Abdullah; Pekdogan, Hakan; Tel, Eyüp; Kaplan, AbdullahIn this study, production rates of Xe-125,Xe-123 and Ba-133,Ba-131,Ba-129,Ba-128 medical isotopes produced by I-127(p, 3n)Xe-125, I-127(p, 5n)Xe-123, Cs-133(p, n)Ba-133mg, Cs-133(p, 3n)Ba-131mg, Cs-133(p, 5n)Ba-129, and Cs-133(p, 6n)Ba-128 reactions have been investigated up to 100 MeV incident proton energy. The pre-equilibrium calculations involve the hybrid model, the geometry-dependent hybrid model and the cascade exciton model. The calculated results are compared with the experimental data taken from the literature.Öğe Pre-equilibrium cross section calculations in alpha induced reactions on 65Cu and 209Bi(Pergamon-Elsevier Science Ltd, 2010) Aydin, Abdullah; Tel, Eyüp; Kaplan, Abdullah; Büyükuslu, H.The nuclear data on (alpha, xn) reactions are very important in the fields of radiation shielding, long-term safe handling of spent fuel and spallation neutron-production. In this study, neutron-production cross sections have been calculated for some target nuclei such as Cu-65 and Bi-269. Hybrid model and geometry dependent hybrid model have been used to calculate the pre-equilibrium neutron-production cross sections. The mean free path parameter's effect for (alpha, xn) neutron-production cross section has been examined. The obtained results have been discussed and compared with the available experimental data. (C) 2010 Elsevier Ltd. All rights reserved.Öğe Triton Emission Spectra in Some Target Nuclei Irradiated by Ultra-Fast Neutrons(Springer, 2010) Tel, Eyüp; Kaplan, Abdullah; Aydin, Abduallah; Büyükuslu, Halim; Demirkol, İskender; Arasoğlu, AliHigh-current proton accelerator technologies make use of spallation neutrons produced in (p,xn) and (n,xn) nuclear reactions on high-Z targets. The produced neutrons are moderated by heavy water. These moderated neutrons are subsequently captured on (3)He to produce tritium via the (n,p) reaction. Tritium self-sufficiency must be maintained for a commercial power plant. So, working out the systematics of (n,t) reaction cross sections and triton emission differential data are important for the given reaction taking place on various nuclei at different energies. In this study, triton emission spectra by using ultra-fast neutrons (incident neutron energy > 50 MeV), the (n,xt) reactions for some target nuclei as (16)O, (27)Al, (56)Fe, (59)Co, (208)Pb and (209)Bi have been investigated. In the calculations, the pre-equilibrium and equilibrium effects have been used. The calculated results have been compared with the experimental data taken from the literature.
