A STUDY OF PHOTONEUTRON REACTIONS USING STATISTICAL ANALYSIS

The 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

A STUDY OF PHOTONEUTRON REACTIONS USING STATISTICAL ANALYSIS†

The well-known inputs for determining the reaction cross section are nuclear level density (NLD) and γ-ray strength functions. In this work, effects of γ-ray strength functions and NLD models on photoneutron reactions of76,77,78Se isotopes are analyzed by using the latest version of TALYS computer code. For γ-ray strength functions, macroscopic and microscopic options which are available in the TALYS, are used in the calculations. Kopecky-Uhl and Brink Axel γ-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 γ-ray strength function that reproduces the experimental data quite well. And then, calculations of photoneutron cross section are redone by using the determined γ-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. © 2022, V N Karazin Kharkiv National University. All rights reserved

Investigation of charged-particle induced reactions on 27Al up to 100 MeV leading to the formation of 22Na and 24Na

Studies 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 27Al are investigated by using TALYS 1.96 computer code. The cross section calculations of 27Al(α,x)22Na, 27Al(α,x)24Na, 27Al(3He,x)22Na, 27Al(3He,x)24Na, 27Al(p,x)22Na and 27Al(p,x)24Na 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. © 2023 Walter de Gruyter GmbH, Berlin/Boston

CROSS-SECTION CALCULATIONS OF PHOTOFISSION REACTIONS FOR 238,239,240,241,242,244Pu ISOTOPES USING NUCLEAR LEVEL DENSITY

Photofission 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 (g, 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. © D. Canbula, B. Canbula, 2022

The combination effect of optical potential and nuclear level density for alpha induced reaction cross sections on 92,94,95Mo isotopes

The 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. © 2024 Elsevier Lt

Investigation of charged-particle induced reactions on 27Al up to 100 MeV leading to the formation of 22Na and 24Na

Studies 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