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1.
Appl Radiat Isot ; 194: 110714, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36774823

RESUMO

Many studies have investigated the influence of theoretical models and factors involved in the acquisition of cross-section data of a nuclear reaction. The implications of different models of various variables such as level density, gamma strength function, and optical potentials on cross-section calculations whether used solo or jointly are investigated in a significant portion of the works conducted in this perspective. The aim of this particular study is to investigate the influence of different optical models on the cross-section calculations in production of several scandium isotopes, known for various medical uses, from several targets with natural abundances by (d,x) reactions. For this purpose, the cross-section calculations using five available deuteron optical models of TALYS code in natTi(d,x)43Sc, natTi(d,x)44mSc, natTi(d,x)46Sc, natTi(d,x)47Sc, natV(d,x)47Sc and natCr(d,x)47Sc reactions were performed and the obtained calculation results were compared with the experimental cross-section data gathered from the literature. To understand whether there is a significant and consistent relationship between the experimental data and the calculation results, both have been plotted together and analyzed with the naked-eye. In addition, the calculations of the mean standardized deviation, the mean relative deviation, the mean ratio and the mean square logarithmic deviation were performed in order to evaluate the results numerically.

2.
Appl Radiat Isot ; 186: 110255, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35523086

RESUMO

In cases where it is not possible to obtain the cross-section values experimentally due to various factors, the importance of obtaining them with theoretical models has been explained in many studies available in the literature. In this context, the comparison of the cross-section values obtained by using the theoretical models with the experimental data will also be very beneficial for updating and developing these models. Existing studies, which also serve this purpose, have given inspiration to this study and it is aimed to examine the effects of the simultaneous use of the alpha optical model potentials and the level density models on the cross-section calculations for some alpha-particle-induced reactions on natural antimony. The effects of theoretical models on the cross-section calculations were investigated by comparing the obtained calculation results with the experimental data taken from the literature. The TALYS code, which is frequently preferred in the literature, was used in all calculations within the scope of this study. For the comparison of the calculated results with the experimental data, not only a visual analysis by graphing the outcomes, but also a mean-weighted-deviation calculation was used, and the findings were interpreted by accounting for both of them.


Assuntos
Partículas alfa , Modelos Teóricos , Partículas alfa/efeitos adversos , Antimônio
3.
Appl Radiat Isot ; 186: 110286, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35576768

RESUMO

Photoneutron reaction cross-sections of 197Au, 187Re, 186W, 181Ta, 94,95,96,97,98,100Mo isotopes were calculated through the TALYS 1.95 nuclear reaction code. The energy range of the incident photon chosen as 7 MeV-30 MeV corresponded to the range of the giant dipole resonance region, which is also an applicable energy range in radiotherapy for many commercial medical linear accelerators. Calculations were performed using three phenomenological level density models available in code, namely the Constant Temperature Fermi Gas Model, the Back-shifted Fermi Gas Model, and the Generalized Superfluid Model. The most convenient level density model for each reaction was chosen using relative variance calculations. The cross-section calculations were repeated using gamma strength function models, Kopecky-Uhl generalized Lorentzian model, Brink-Axel Lorentzian model, and Goriely's hybrid model and the best level density model was kept constant. The calculated data and the experimental data from the international Experimental Nuclear Reaction Data Library were analysed and compared graphically.


Assuntos
Nêutrons , Aceleradores de Partículas , Método de Monte Carlo , Fótons , Síncrotrons
4.
Appl Radiat Isot ; 176: 109875, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34311220

RESUMO

A common feature of scientific studies is that when experimental observation data are not available, theoretical calculations are used to obtain information about the subject under investigation. In this context, many parameters and theoretical models have been developed that can be used in nuclear physics studies just as it is in other branches of sciences. It is intended that by doing so, theoretical models can be improved using recent experimental data while also learning about outcomes where experimental data is unavailable or difficult to access. Among the many theoretical models available, there are also deuteron optical models whose effects are examined in this study. The objective of this study is to examine the effects of different deuteron optical models on the cross-section calculations of deuteron induced reactions on natural germanium. The cross-section values of natGe(d,x)70As, natGe(d,x)71As, natGe(d,x)72As, natGe(d,x)73As, natGe(d,x)74As and natGe(d,x)76As reactions were calculated using five deuteron optical models in the TALYS code's v1.95 for this aim, and the results were compared to the experimental data available in the database known as Experimental Nuclear Reaction Data (EXFOR) library. Graphics and quantitative analyses were also used to present the findings and interpretations of the outcomes.

5.
Appl Radiat Isot ; 170: 109584, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33445056

RESUMO

The aim of this study is to develop an accurate artificial neural network algorithm for the cross-section of (n,p) reactions at 14.5 ∓0.5 MeV neutron energy which is important to developing materials for fusion reactor design. The experimental data used at artificial Neural network calculations have been taken from the Experimental Nuclear Reaction Data (EXFOR) database. Bayesian algorithm has been used at training section of artificial neural network. Regression (R) values of artificial neural network calculations have been found as 0.99363, 0.98574 and 0.99257 for training, testing and all process respectively. In addition to artificial neural network calculations, TALYS 1.95 nuclear reaction code has been used to reproduce (n,p) reactions at 14.5 ∓0.5 MeV. Two-component exciton model and Constant Temperature Fermi Gas Model have been used as pre-equilibrium and level density models respectively. Mean square errors of our calculations have been found 48.51 and 495.06 for artificial neural network and TALYS 1.95 respectively. Artificial Neural network estimations have been compared and analyzed with the TALYS 1.95 calculations and the experimental data taken from EXFOR database.

6.
Appl Radiat Isot ; 166: 109429, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32992112

RESUMO

56Fe(n,p)56Mn, 55Mn(n,p)55Cr, 52Cr(n,p)52V, 56Fe(n, α)53Cr, 55Mn(n, α)52V and 52Cr(n, α)49Ti reactions are evaluated using four phenomenological nuclear level density models from reaction threshold to 20 MeV. The calculated data is compared with the experimental nuclear reaction data from EXFOR database. Statistical factors H, D and R are computed to identify the best fit. Level density parameters are adjusted for further improvement of the fitting. Back shifted Farmi-gas model gives a resemblance of neutron-induced 56Fe, 55Mn and constant temperature Fermi-gas model gives a closeness for 52Cr reaction with our new parameter values.

7.
Appl Radiat Isot ; 165: 109356, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32810729

RESUMO

The knowledge of the interaction of photons with matter is of vital importance to investigate fundamental nuclear physics problems. Giant dipole resonance (GDR) mechanism is dominant up to 30 MeV at photo-absorption cross-section. The photo-absorption cross-section curve against the photon energy displays one or multi-peak Lorentzian functions according to the deformation of the nucleus. Theoretical photo-absorption cross-section calculations generally focus on the estimation of GDR parameters. Theoretical reaction codes use GDR parameters to reproduce photon-induced nuclear reactions. In this study, photo-neutron cross-section calculations of 54,56Fe, 90,91,92,94Zr, 93Nb, and 107Ag isotopes have been done with the TALYS 1.8 and EMPIRE 3.2.2 nuclear reaction codes in the GDR region. During these calculations, both codes were firstly operated by using the predefined and existing GDR parameters within the codes. Later on, a new set of GDR parameters have been obtained by running a Lorentzian model based code in where the available experimental data are also considered. Levenberg-Marquardt algorithm has been used with 10-6 function tolerances and 400 iterations for optimization. These new obtained GDR parameters then replaced with the existing GDR parameters within the TALYS code and the photo-neutron cross-section calculations for the investigated isotopes have been repeated. Ultimately, in order to discuss the outcomes and the effects of using new GDR parameters, obtained results were analyzed by comparing them with the experimental data from the Experimental Nuclear Reaction Data (EXFOR) library.

8.
Appl Radiat Isot ; 143: 6-10, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30368053

RESUMO

Scientists have been focused on fusion reactor studies to overcome the increasing energy demand. The materials, which have the potential to be used in fusion reactors must be resistant to the harmful effects of radiation in the manner of material itself. Selection of the appropriate materials to be used in nuclear reactors has a crucial importance to achieve the maximum efficiency and security. Ti, V, Ni and Cu are known as some of the constructional fusion materials. Existence of many knowledge about those materials provides countless advantages to the researchers and one of them is the cross-section, which basically means the probability of a nuclear reaction's occurrence. In addition to the cross-section, there exist some other parameters, which could be pointed as gamma strength function and level density models that affect the theoretical calculations. In this study, photon induced reaction cross-sections of 46,50Ti, 51V, 58Ni and 63Cu target isotopes have been calculated by using TALYS 1.8 code with different gamma strength functions in the giant dipole resonance region. For gamma strength functions Kopecky-Uhl generalised Lorentzian Model, Brink-Axel Lorentzian Model, Hartree-Fock BCS tables, Hartree-Fock-Bogolyubov tables and Goriely's Hybrid Model have been employed. To appoint the best gamma strength function model, the relative variance calculations have been performed. Also, reaction cross-sections have been recalculated by using the best gamma strength function models through the different level density options. Constant Temperature Fermi Gas Model, Back Shifted Fermi Gas Model and Generalised Super Fluid Model have been employed for level density calculations. Experimental data for the investigated reactions have been taken from EXFOR library and used for comparisons of the obtained calculation results.

9.
Appl Radiat Isot ; 139: 81-85, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29729485

RESUMO

This study provides current evidence about cross-section production processes in the theoretical and experimental results of neutron induced reaction of uranium isotope on projectile energy range of 1-100 MeV in order to improve the reliability of nuclear stimulation. In such fission reactions of 235U within nuclear reactors, much amount of energy would be released as a product that able to satisfy the needs of energy to the world wide without polluting processes as compared to other sources. The main objective of this work is to transform a related knowledge in the neutron-induced fission reactions on 235U through describing, analyzing and interpreting the theoretical results of the cross sections obtained from computer code COMPLET by comparing with the experimental data obtained from EXFOR. The cross section value of 235U(n,2n)234U, 235U(n,3n)233U, 235U(n,γ)236U, 235U(n,f) are obtained using computer code COMPLET and the corresponding experimental values were browsed by EXFOR, IAEA. The theoretical results are compared with the experimental data taken from EXFOR Data Bank. Computer code COMPLET has been used for the analysis with the same set of input parameters and the graphs were plotted by the help of spreadsheet & Origin-8 software. The quantification of uncertainties stemming from both experimental data and computer code calculation plays a significant role in the final evaluated results. The calculated results for total cross sections were compared with the experimental data taken from EXFOR in the literature, and good agreement was found between the experimental and theoretical data. This comparison of the calculated data was analyzed and interpreted with tabulation and graphical descriptions, and the results were briefly discussed within the text of this research work.

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