Browsing by Author "Canbula, B"
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Item An investigation of the role of spectroscopic factors in the breakup reaction of 11BeCanbula, B; Bulur, R; Canbula, D; Babacan, HThe experimental elastic cross section data of the projectile Be-11 on target C-12 at 49.3 MeV/nucleon energy is analysed. The calculations for the elastic scattering are performed by the phenomenological optical model. The different optical potentials to include breakup effects into the calculations, which are neutron+C-12, neutron+ Be-10 and Be-10+C-12, are described with the aid of the global potentials for neutron interactions and fitted to experimental data for the core and target interaction. Also, the first analysis of the optical model for Be-10 on target C-12 at 39.1 MeV is done for building the interaction potential of the core and the target for Be-11. For investigating the effects of the spectroscopic factors, obtained factors from the direct capture process using the nuclear level density are compared with the previous cross section and spectroscopic factor results. Obtained results for the elastic cross section reproduce the experimental data very well and show the requirement of including spectroscopic properties such as, spectroscopic factors and density of the excited states, to explain this elastic cross section data.Item Renormalization of the γ-ray strength functions of light nucleiCanbula, B; Ersan, S; Babacan, Hgamma-ray strength function is the key input for the photonuclear reactions, which have a special astrophysical importance, and should be renormalized by using the nuclear level density for calculating the theoretical average radiative capture width, but performing such renormalization is challenging for light nuclei. With this motivation, recently introduced level density parameter formula including collective effects is used to calculate the average radiative capture width of light nuclei, and therefore to renormalize their gamma-ray strength functions. Obtained normalization factors are tested in (n, gamma) reactions for the necessity of renormalization for light nuclei.Item Collective effects in deuteron induced reactions of aluminumCanbula, BCross sections of Al-27(d,x)Na-22, Al-27(d,x)Na-24, and Al-27(d,x)Mg-27 reactions are calculated by using TALYS 1.6 computer code with different nuclear level density models, which are composite Gilbert-Cameron model, back-shifted Fermi gas model, generalized superfluid model, and recently proposed collective semi-classical Fermi gas model in the energy range of 3-180 MeV. The results are compared with the experimental data taken from EXFOR library. In these deuteron induced reactions, collective effects are investigated by means of nuclear level density models. Collective semi-classical Fermi gas model including the collective effects via the level density parameter represents the best agreement with the experimental data compared to the other level density models, especially in the low deuteron bombarding energies where the collective effects dominate. (C) 2016 Elsevier B.V. All rights reserved.Item Nuclear level density as a tool for probing the inelastic scattering of 6HeCanbula, B; Babacan, HThe cross sections are calculated for the both elastic and inelastic scattering of He-6 from C-12 and He-4. A phenomenological optical potential is used to describe the elastic scattering. He-4 is taken as spherical and inelastic couplings to the first excited states of He-6 and C-12 are described with collective rotational model and coupled-channels method. Deformation lengths for He-6 and C-12 are determined from semi-classical nuclear level density model by using Laplace-like formula for the nuclear level density parameter. The comparison of the predicted and the measured cross sections are presented to test the applicability of nuclear level density model to the light exotic nuclei reactions. Good agreement is achieved between the predicted and measured cross sections.Item Probing 6He induced reactions with nuclear level densityCanbula, D; Canbula, B; Babacan, HIn this study, both elastic and inelastic cross sections of the light exotic nucleus He-6 on C-12 and He-4 at energies of 18 MeV, 30 MeV, 3.8 MeV, 4.2 MeV, 4.7 MeV, 5.1 MeV, 5.4 MeV, and 5.8 MeV, as well as the quasi-elastic cross section of He-6 on Be-9 at 16.2 MeV and 21.3 MeV, are calculated using the coupled-channel method. The deformation parameters of the first excited states of He-6, Be-9 and C-12 are obtained through the collective nuclear level density. The results align well with the available experimental data. It is demonstrated that the collective nuclear level density is essential to reduce the uncertainty between the deformation parameter and the optical model parameters. Furthermore, it is shown that the first excited state of both the projectile and the target must be considered in calculations He-6 + Be-9 scattering at increasing energies.Item A Laplace-like formula for the energy dependence of the nuclear level density parameterCanbula, B; Bulur, R; Canbula, D; Babacan, HCollective effects in the level density are not well understood, and including these effects as enhancement factors to the level density does not produce sufficiently consistent predictions of observables. Therefore, collective effects are investigated in the level density parameter instead of treating them as a final factor in the level density. A new Laplace-like formula is proposed for the energy dependence of the level density parameter, including collective effects. A significant improvement has been achieved in agreement between observed and predicted energy levels. This new model can also be used in both structure and reaction calculations of the nuclei far from stability, especially near the drip lines. (C) 2014 Elsevier B.V. All rights reserved.Item Effects of single-particle potentials on the level density parameterCanbula, B; Bulur, R; Canbula, D; Babacan, HThe new definition of the energy dependence for the level density parameter including collective effects depends strongly on the semi-classical approach. For this method, defining an accurate single-particle potential is of great importance. The effect of the single-particle potential terms, which are central, spin-orbit, harmonic oscillator, Woods-Saxon and Coulomb potential, both for spherical and deformed cases, on the level density parameter was investigated by examining the local success of the global parameterizations of eight different combinations of these terms. Among these combinations, the sum of the central, spin-orbit, harmonic oscillator and Coulomb potentials, gives the most accurate predictions compared with experimental data. The local selections of the global parameterizations show that the single-particle models, which are based on the Woods-Saxon potential as the main term, are more suitable candidates than the models based on harmonic oscillator potential to extrapolate away far from stability. Also it can be concluded that the contribution of the Coulomb interaction, both around the closed and open shells is not neglectable.Item Calculation of the level density parameter using semi-classical approachCanbula, B; Babacan, HThe level density parameters (level density parameter a and energy shift delta) for back-shifted Fermi gas model have been determined for 1136 nuclei for which complete level scheme is available. Level density parameter is calculated by using the semi-classical single particle level density, which can be obtained analytically through spherical harmonic oscillator potential. This method also enables us to analyze the Coulomb potential's effect on the level density parameter. The dependence of this parameter on energy has been also investigated. Another parameter, delta, is determined by fitting of the experimental level scheme and the average resonance spacings for 289 nuclei. Only level scheme is used for optimization procedure for remaining 847 nuclei. Level densities for some nuclei have been calculated by using these parameter values. Obtained results have been compared with the experimental level scheme and the resonance spacing data. (C) 2011 Elsevier B.V. All rights reserved.Item Analysis of elastic, quasielastic, and inelastic scattering of lithium isotopes on a 28Si targetCanbula, B; Canbula, D; Babacan, HThe elastic and inelastic cross sections of Li-6 on Si-28 at 240 MeV, and quasielastic cross section of Li-7 and Li-11 on Si-28 at 177.8 and 319 MeV, respectively, are analyzed with the coupled-channels method. The collective nuclear level density is used to determine the deformation parameter regarding to the first-excited state of Si-28. The results are in agreement with the experimental data and indicate the need of using a nuclear structure model such as nuclear level density to reduce the ambiguity between the optical model parameters and the deformation parameter. Additionally, the spin-orbit potential is found to have an important role in reproducing the data of the quasielastic scattering of Li-7 and Li-11 on a Si-28 target.Item Statistical investigation of the angular momentum dependence of the nuclear level density parameterCanbula, BThe nuclear level density (NLD) parameter is crucial for calculating cross-sections in nuclear physics, astrophysics, reactor design, and medical physics. Spin and parity, along with excitation energy, are fundamental properties of an excited nuclear level. Previous investigations into the NLD's dependence on spin and parity have primarily used approximate methods like parity equidistribution and Gaussian distribution of spins. However, the specific impact of spin and parity on the NLD parameter, a key component in NLD formulation, has not been extensively studied. We examined the spin and parity dependence of the NLD parameter. Our findings demonstrate that the NLD parameter's dependency on both excitation energy and angular momentum can be accurately characterized by a Laplace distribution, highlighting the complex interplay of these factors in nuclear physics.Item A STUDY OF PHOTONEUTRON REACTIONS USING STATISTICAL ANALYSISCanbula, D; Canbula, BThe well-known inputs for determining the reaction cross section are nuclear level density (NLD) and y-ray strength functions. In this work, effects of y-ray strength functions and NLD models on photoneutron reactions of 76 ,77 ,78Se isotopes are analyzed by using the latest version of TALYS computer code. For y-ray strength functions, macroscopic and microscopic options which are available in the TALYS, are used in the calculations. Kopecky-Uhl and Brink Axel y-ray strength function models as macroscopic options, Hartree-Fock BCS tables, Hartree-Fock Bogolyubov tables and Goriely's hybrid model as microscopic options are preferred. The statistical analysis is carried out to determine the y-ray strength function that reproduces the experimental data quite well. And then, calculations of photoneutron cross section are redone by using the determined y-ray strength function via the NLD models. The Constant Temperature Model (CTM), Back Shifted Fermi Gas Model (BSFGM) and Generalized Superfluid Model (GSM) are preferred to use in NLD calculations. The predictions are compared with each other and the available experimental data. EXFOR library is used to take all experimental data.Item The combination effect of optical potential and nuclear level density for alpha induced reaction cross sections on 92,94,95Mo isotopesCanbula, D; Canbula, BThe theoretical studies of charged particle induced reactions are important to improve and study the radioisotope production, especially in reactions where the experimental data are incomplete or insufficient. In this study, cross section of alpha induced of 92,94,95Mo isotopes are calculated and analyzed by using different alpha optical model potentials and nuclear level density models with TALYS code. The effects of alpha optical model potentials and nuclear level density are analyzed separately and together for each reaction. To determine the best combination of models, chi-squared values are calculated for all combination cases. The commonly used program is TALYS to calculate the reaction cross section. For the calculations, the latest version of TALYS nuclear code version 1.96 is used. The experimental data are taken carefully for all reactions from experimental nuclear reaction data base (EXFOR). The obtained results are compared with these data and discussed. A good agreement between the calculated and experimental data is clearly presented for all analyzed reactions. It is seen from the results that alpha optical model potentials and nuclear level density models have an effective role on cross section calculations of alpha induced reactions.Item Investigation of charged-particle induced reactions on 27Al up to 100 MeV leading to the formation of 22Na and 24NaCanbula, D; Canbula, BStudies using theoretical models are of great importance for understanding of reaction process and its nature. In this study, nuclear level density model calculations of the cross sections of Al-27 are investigated by using TALYS 1.96 computer code. The cross section calculations of Al-27(alpha,x)Na-22, Al-27(alpha,x)Na-24, Al-27(3He,x)Na-22, Al-27(3He,x)Na-24, Al-27(p,x)Na-22 and Al-27(p,x)Na-24 reactions were carried out for incident particle energy up to 100 MeV. In these calculations, four nuclear level density models, namely constant temperature model (CTM), back-shifted Fermi gas model (BSFGM), generalized superfluid model (GSM) and recently proposed semi-classical Fermi gas model (CSCFGM) are used. This model is developed using the simplest model BSFGM. The most obvious difference between CSCFGM and other models is the inclusion of the collective effects in the base of the formulation. The predicted results are discussed and compared with each other and the available experimental data taken from EXFOR library. In order to better evaluate the model results, chi-squared values are calculated and compared with each other for all analyzed reactions. According to the chi-squared results, CSCFGM gives closer predictions to the experimental data compared with the other models in 4 of the 6 analyzed reactions. Therefore, in this study, it is presented that this model can be reliably used in the reaction cross section calculations.Item Cross-Section Calculations for the Production of 123I and 124I Radioisotopes via (p,n) and (p,2n) Reactions Using Collective Nuclear Level Density ModelCanbula, D; Canbula, BSome isotopes such as I-123 and I-124 are useful in medical science, and thus, the production of these isotopes has great importance. Iodine-123 is the gamma-emitting radioisotope of radioiodine, and I-124 is the long-lived positron-emitting radioisotope of radioiodine, and they have applications in diagnosis via both Single Photon Emission Computed Tomography (SPECT)/Positron Emission Tomography (PET) and radiotherapy. Therefore, many theoretical and experimental studies are performed for these isotopes. In this study, the cross sections of the Te-123(p,n), Te-124(p,n), and Te-124(p,2n) reactions up to 31 MeV, where I-123 and I-124 can be produced, are calculated by importing the Collective Semi-Classical Fermi Gas Model (CSCFGM) to the Talys 1.96 computer code. The predictions are compared with the default theoretical calculations of Talys 1.96 and existing experimental data taken from the EXFOR library. The results are in good agreement with the experimental data, and therefore, CSCFGM looks to be a useful tool for predicting the production reactions of some therapeutic isotopes.Item CROSS-SECTION CALCULATIONS OF PHOTOFISSION REACTIONS FOR 238,239,240,241,242,244Pu ISOTOPES USING NUCLEAR LEVEL DENSITYCanbula, D; Canbula, BPhotofission cross-sections of 238,239,240,241,242,244Pu isotopes are theoretically investigated with the collective semi-classical Fermi gas model (CSCFGM) by using Talys computer code in the energy range 1 -30 MeV. Nuclear level density has significant importance to define the structural properties of nuclei. CSCFGM is a nuclear level density model, that includes collective (rotational and vibrational) effects as well as the pairing and shell effects, and is used to analyse the (gamma, f) reactions of plutonium isotopes. The experimental data for all reactions are taken from EXFOR library. The theoretical predictions are in agreement with the experimental data, Talys code without changing the input, and the evaluated nuclear cross-section data from TENDL 2021 library.Item A new proton spectra for natC(p,xp) reaction at Ep=7 and 30 MeVKucuk, Y; Zholdybayev, TK; Canbula, B; Mukan, Z; Sadykov, BM; Nassurlla, M; Ismailov, KM; Yücel, MB; Boztosun, IIn this paper, we present a new measurement of the inclusive cross section (p,xp) reactions on Cu-nat at incident energies of E-p = 7 and 30 MeV. The (p,xp) reaction at E-p= 7 MeV on Cu-nat is measured for the first time and (p,xp) and (p,x alpha) inclusive cross section for the same target at E-p = 30 MeV is re-measured in order to improve the quality of the previous experimental data. For both energies, the mechanism of the pre-equilibrium reactions as well as the level of energy dependence are discussed and the adequacy of the theoretical models in explaining the newly measured experimental data is also assessed by comparing the experimental data with the results of the Hauser-Feshbach and Exciton models. We use the microscopic approach based on nucleon-nucleon interaction to produce the complex nuclear potential.