Geometry Dependent Hybrid Model Research Articles

Investigating the excitation functions of the neutron-induced reactions leading to the radioactive products on natural titanium isotopes

In this study, the excitation functions of some (n, x) reactions leading to the radioisotope products on natural titanium isotopes, which is an important material for fusion technology, are calculated by using the ALICE/ASH and TALYS 1.95 codes. Besides, the effects of the phenomenological and the microscopic nuclear level density models on these excitation functions are investigated by using the two-component exciton and geometry dependent hybrid models. The obtained results for the considered reactions in this study are compared with the available experimental and ENDF/B-VIII data, and the suitable nuclear level density model is determined for each reaction. According to the results, the phenomenological nuclear level density models are generally in good agreement with experimental data, except for 48Ti(n,d) and 50Ti(n,γ) reactions. Also, the results of this study can be used to predetermine radiotoxicity in the structural material for a fusion reactor.

Production cross-section calculations of 111In via proton and alpha-induced nuclear reactions

[Formula: see text], a known gamma emitter, is used for many medical purposes such as imaging of myocardial metastases. It can be produced by using different nuclear reactions. In this study, the reactions of [Formula: see text]Ag([Formula: see text]2n)[Formula: see text], [Formula: see text](p,[Formula: see text]n)[Formula: see text], [Formula: see text](p,[Formula: see text]2n)[Formula: see text], [Formula: see text](p,[Formula: see text]3n)[Formula: see text] and [Formula: see text](p,[Formula: see text]4n)[Formula: see text], which are the production routes of [Formula: see text], were investigated. Production cross-section calculations were performed by using equilibrium and pre-equilibrium models of TALYS 1.95 and EMPIRE 3.2 nuclear reaction codes. Hauser–Feshbach Model was appointed in both codes for calculations of equilibrium approximations. Exciton and Hybrid Monte Carlo Simulation (HMS) models were used in the EMPIRE 3.2, whereas Two-Component Exciton and Geometry Dependent Hybrid Model, which is implemented to TALYS code, has been used in the TALYS 1.95 for pre-equilibrium reactions. Also, a weighting matrix of the nuclear models was obtained by using statistical variance analysis. The optimum beam energy to obtain [Formula: see text] has been determined by using the results obtained from this weighting matrix.

Investigation of (n,2n) reaction cross sections on Pd and Cd isotopes using equilibrium and pre-equilibrium models

We have carried out calculations for cross sections of 102Pd(n,2n)101Pd, 110Pd(n,2n)109Pd, 106Cd(n,2n)105Cd, 108Cd(n,2n)107Cd, 110Cd(n,2n)109Cd, 114Cd(n,2n)113Cd and 116Cd(n,2n)115Cd reactions via nuclear models which are based on the equilibrium and pre-equilibrium emissions in the interactions of nuclei with neutron particles. The cross sections were determined by means of the model codes EMPIRE 3.2, ALICE/ASH and TALYS 1.8. Besides, the equilibrium and pre-equilibrium effects were performed using Weisskopf-Ewing model, Geometry Dependent Hybrid model, Exciton model and Two-component Exciton model at neutron energies from threshold to 20 MeV. Effects of different level density models on the equilibrium calculations have also been discussed. Furthermore, the empirical systematics, which were suggested in our previous study and in the literature, were used to calculate the (n,2n) cross sections at energies around 14.5 MeV. Thereby, the data obtained were discussed and compared with the measured data in the literature.

New evaluation of general purpose neutron data for stable W-isotopes up to 200 MeV

In the frame of the Power Plant Physics and Technology of EUROfusion, new evaluations of general purpose neutron cross-section data were performed for the 180,182,183,184,186W isotopes covering the neutron energy up to 200 MeV. A special version of the TALYS nuclear model code implementing the geometry dependent hybrid model supplied with models for the non-equilibrium cluster emission was applied for calculations of the nuclide production and the energy distribution of the emitted particles. The parameters of the GDH model were properly estimated using measured data for individual tungsten isotopes. The neutron cross-sections were evaluated making use of available experimental data, systematics including estimated A-dependence of components of gas production cross-sections, and covariance information produced as part of the evaluation process. The BEKED code package, developed at KIT, was applied for calculations of co-variances using a dedicated Monte Carlo method. The evaluated data were processed into standard ENDF data format using the TEFAL code and the FOX module of the BEKED system. The evaluated data files were checked for errors and inconsistencies, processed with the NJOY code into ACE data format, and benchmarked against available integral experiments with MCNP neutron transport calculations.

Study on cross section calculations for (n,p) nuclear reactions of cadmium isotopes

A theoretical study of the cross sections of (n,p)reactions on Cadmium isotopes has been performed using the Hauser-Feshbach model, Weisskopf-Ewing model, Exciton model, Two-component exciton model and Geometry dependent hybrid model for the incident energies from the reaction threshold to 20MeV. Furthermore, the empirical formulae based on the different systematics at the energies near 14.5MeV were used for calculating the (n,p)nuclear cross sections. Finally, the results of the present paper are discussed and compared with the experimental cross sections and TENDL-2017 data found in the literature.

A study on the excitation functions of 60,62Ni(α,n), 60,61Ni(α,2n), 58,64Ni(α,p), natNi(α,x) reactions

The prediction of nuclear cross-section data is crucial, especially in the absence of experimental data or in the difficulty of these experimental data. Nickel (Ni) is an important material in fusion and fission reactor technologies, the production of radionuclides in nuclear medicine, and many other fields. In this study, the excitation functions for 60,62Ni(α,n), 60,61Ni(α,2n), 58,64Ni(α,p), and natNi(α,x) reactions have been investigated by using pre-equilibrium reaction models. The calculations of the excitation functions for the reactions are used with the geometry-dependent hybrid model in ALICE/ASH code and the two-component exciton model in TALYS 1.8 code. The obtained results are compared to each other, and the experimental data are taken from the EXFOR database.

On the behavior of cross-sections of charged particle-induced reactions of 181Ta target

The production of nuclear energy from fusion reaction with no CO2 emission is one of the most attractive sources for the future. The unprecedented physical and mechanical properties for structural materials are very important in the nuclear fusion reactor design. So, tantalum material is a valuable candidate for plasma-facing materials in the fusion devices. In this paper, nuclear excitation functions for the [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] reactions are obtained using the nuclear codes TALYS 1.8 and ALICE/ASH. The contribution of pre-equilibrium and equilibrium processes in these reactions is investigated. In the calculations, the Weisskopf–Ewing and Hauser–Feshbach formalisms for the equilibrium particle emission, and the two-component exciton, hybrid and geometry-dependent hybrid formalisms for the pre-equilibrium particle emission are used. Hence, the cross-sections calculated are compared with the measured values. It is observed that the cross-section results of the geometry-dependent hybrid model match fairly well with the experimental measurements.

The Study of (n, 2n) Reaction Cross Sections for Ce and Nd Isotopes up to 20 MeV

Neutron cross section calculations for 136Ce(n, 2n)135Ce, 138Ce(n, 2n)137Ce, 140Ce(n, 2n)139Ce, 142Ce(n, 2n)141Ce, 142Nd(n, 2n)141Nd, 144Nd(n, 2n)143Nd, 146Nd(n, 2n)145Nd, 148Nd(n, 2n)147Nd, and 150Nd(n, 2n)149Nd were done in the incident energy range from 10 to 20 MeV. The calculations were performed using three codes TALYS-1.6 for two-component Exciton model, EMPIRE-3.2 Malta for Exciton model, and ALICE/ASH for the Geometry-Dependent Hybrid (GDH) model. The results of model calculations were compared with the available experimental data and also with the evaluated data in the TENDL-2015 (based on the modified TALYS code), ENDF/B-VII.1 libraries. The calculated cross section data were compared with the available experimental data obtained from EXFOR and also compared with semiempirical formulas around 14–15 MeV. The results of model calculation were found to be in good agreement with the experimental data given in literature and semiempirical data around 14–15MeV.

Theoretical determination of (d, n) and (d, 2n) excitation functions of some structural fusion materials irradiated by deuterons

Nuclear fusion is one of the world’s primary energy sources. Studies on the structural fusion materials are very important in terms of the development of fusion technology. Chromium, nickel, zinc, scandium, titanium, and yttrium are important structural fusion materials. In this paper, for use in nuclear science and technology applications, the excitation functions of the 50Cr(d, n)51Mn, 58Ni(d, n)59Cu, 64Zn(d, n)65Ga, 66Zn(d, n)67Ga, 45Sc(d, 2n)45Ti, 47Ti(d, 2n)47V, 48Ti(d, 2n)48V, and 89Y(d, 2n)89Zr nuclear reactions were investigated. The calculations that are based on the pre-equilibrium and equilibrium reaction processes were performed using ALICE–ASH computer code. A comparison with geometry-dependent hybrid model has been made using the initial exciton numbers n 0 = 4–6 and level density parameters α = A/5; A/8; A/11. Also, the present model-based calculations were compared with the cross sections obtained using the formulae suggested from our previous studies. Furthermore, the cross section results have been compared with TENDL data based on TALYS computer code and the measured data in the literature.

Model-based predictions for nuclear excitation functions of neutron-induced reactions on 64 ,66 −68 Zn targets

Abstract In this paper, nuclear data for cross sections of the 64Zn(n,2n)63Zn, 64Zn(n,3n)62Zn, 64Zn(n,p)64Cu, 66Zn(n,2n)65Zn, 66Zn(n,p)66Cu, 67Zn(n,p)67Cu, 68Zn(n,p)68Cu, and 68Zn(n,α)65Ni reactions were studied for neutron energies up to 40 MeV. In the nuclear model calculations, TALYS 1.6, ALICE/ASH, and EMPIRE 3.2 codes were used. Furthermore, the nuclear data for the (n,2n) and (n,p) reaction channels were also calculated using various cross-section systematics at energies around 14–15 MeV. The code calculations were analyzed and obtained using the different level densities in the exciton model and the geometry-dependent hybrid model. The results obtained from the excitation function calculations are discussed and compared with literature experimental data, ENDF/B-VII.1, and the TENDL-2015 evaluated data.

Reaction cross section calculation of some alkaline earth elements

Reaction cross section knowledge is crucial to application nuclear physics such as medical imaging, radiation shielding and material evaluations. Nuclear reaction codes can be used if the experimental data are unavailable or are improbably to be produced because of the experimental trouble. In this study, there action cross sections of some target alkaline earth elements have been calculated by using pre-equilibrium and equilibrium nuclear reaction models for nucleon induced reactions. While these calculations, the Hybrid Model, the Geometry Dependent Hybrid Model, the Full Exciton Model, the Cascade Exciton Model for pre-equilibrium reactions and the Weisskopf-Ewing Model for equilibrium reactions have been used. The calculated cross sections have been discussed and compared with the experimental data taken from Experimental Nuclear Reaction Data library.

New evaluations of n + Cu and n + Zr cross-section data for neutron energies up to 200 MeV

This work presents evaluated general purpose nuclear data files for the n+ 63,65 Cu and n+ 90,91,92,94,96 Zr reactions for neutron energies up to 200 MeV. The TALYS-1.8 code was used for the nuclear model simulations in the energy range from 1 keV to 200 MeV. To improve the pre-equilibrium particle emission the Geometry-Dependent Hybrid model (GDH) was used as option implemented in an extended version of the code as option. Resonance data based on recent measurements and their covariances were included in the files. A set of covariance data for all nuclear reactions was also prepared and included in the evaluations. The adjustments of the nuclear model parameters were performed to fit both available differential and integral measured data. The evaluated data were carefully checked against the latest fusion relevant integral measurements.

Excitation function calculations for α + 93Nb nuclear reactions

In this study, the excitation functions of alpha-induced reactions on the 93Nb target nucleus were calculated by using ALICE-ASH code. The hybrid model, Weisskopf-Ewing model and geometry dependent hybrid model in this code were used to understand the alpha-niobium interaction. The contribution on the nuclear interaction of compound and pre-compound processes, with variation of the incident alpha particle energy, was presented. Furthermore, the reaction cross sections were calculated by using different level density models such as Superfluid nuclear model, Fermi gas model and Kataria-Ramamurthy Fermi gas model. Obtaining a good agreement between the calculated and the measured cross sections, the exciton numbers and the nuclear level density models were varied. Finally, the proper choice of the exciton numbers and the nuclear level density models was found to be quite important in order to obtain the more realistic cross section values.

Cross Section Calculations of (n,2n) and (n,p) Nuclear Reactions on Germanium Isotopes at 14–15 MeV

Neutron incident reaction cross sections of Germanium isotopes (70,72,74,76Ge) were investigated for the (n,2n) and (n,p) reactions around 14–15 MeV. Cross section calculations have been presented for 70Ge(n,2n)69Ge, 72Ge(n,2n)71Ge, 74Ge(n,2n)73Ge, 76Ge(n,2n)75Ge, 70Ge(n,p)70Ga, 72Ge(n,p)72Ga, 74Ge(n,p)74Ga, and 76Ge(n,p)76Ga reactions. Theoretical calculations were performed with four different computer codes: ALICE/ASH for the Geometry Dependent Hybrid model, TALYS 1.6 for two component Exciton model, EMPIRE 3.2 Malta for Exciton model and PCROSS for Full Exciton model with the incident neutron energy up to 20 MeV. The (n,2n) and (n,p) reaction cross section calculations were compared with empirical formulas derived by several researchers and compared with the experimental data obtained from EXFOR database as well as with evaluated Nuclear data files (ENDF/B-VII.1: USA 2014). Results show good agreement between the theoretical calculations having a major importance in nuclear data evaluation calculations and the experimental data from literature.

Computations of (α,xn) Reaction Cross-Section for 107,109Ag Coated Materials with Possible Application in Accelerators and Nuclear Systems

Silver plated shields are used in components and structures of fusion reactors that may be effected due to the huge radiation. For this reason, we focused on excitation functions of 107,109Ag on alpha induced reactions. For simplicity to examining the events of nuclear physics, nuclear reaction codes such as ALICE/ASH, TALYS, CEM, EMPIRE, PCROSS, GEANT4 and FLUKA that includes different models have been used for many years. In this study, the cross-sections of (α,xn) reactions, where x = 1–5, for 107,109Ag by using nuclear reaction codes ALICE/ASH and TALYS 1.6 were computed. Hybrid and Geometry Dependent Hybrid Models were used in ALICE/ASH whereas Two-Component Exciton Model was used in TALYS 1.6 reaction codes. Energy ranges of alpha particles for 107Ag and 109Ag were taken into computations as 9.2–96.8 and 10.2–71.2 MeV, respectively. Computed results are also compared each other and with experimental data existing in the literature for each reaction.

Competition between the compound and the pre-compound emission processes in α-induced reactions at near astrophysical energy to well above it

The study of pre-compound emission in α-induced reactions, particularly at the low incident energies, is of considerable interest as the pre-compound emission is more likely to occur at higher energies. With a view to study the competition between the compound and the pre-compound emission processes in α-induced reactions at different energies and with different targets, a systematics for neutron emission channels in targets 51V, 55Mn, 93Nb, 121, 123Sb and 141Pr at energy ranging from astrophysical interest to well above it, has been developed.The off-line γ-ray-spectrometry based activation technique has been adopted to measure the excitation functions. The experimental excitation functions have been analysed within the framework of the compound nucleus mechanism based on the Weisskopf-Ewing model and the pre-compound emission calculations based on the geometry dependent hybrid model. The analysis of the data shows that experimental excitation functions could be reproduced only when the pre-compound emission, simulated theoretically, is taken into account.The strength of pre-compound emission process for each system has been obtained by deducing the pre-compound fraction. Analysis of data indicates that in α-induced reactions, the pre-compound emission process plays an important role, particularly at the low incident energies, where the pure compound nucleus process is likely to dominate.

Study on (n,2n) and (n,p) reactions of strontium nucleus

The cross sections for (n,2n) and (n,p) nuclear reactions on 84,86,88,90Sr target nuclei up to 30MeV from threshold have been investigated. The determination of the cross sections has been done employing the codes ALICE/ASH, PCROSS, CEM03.01 which taking into consideration compound and precompound emissions. Calculations have been performed by using the Weisskopf Ewing model (WEM) of compound reaction mechanism, and the Hybrid model (HM), Geometry Dependent Hybrid model (GDHM) and Full Exciton model (FEM) of precompound reaction mechanism, and Cascade Exciton model (CEM) including Cascade interactions, and the empirical and semi-emipirical systematics. In order to test the theoretical nuclear models, the data obtained from the excitation function calculations are discussed and compared with available experimental values, ENDF/B-VII.1 and TENDL-2014 libraries. Finally the new cross section results calculated in the present paper may be useful for nuclear energy applications.

Cross Section Analysis for Neutron and Proton Induced Reactions on 55Mn Material

Nuclear data on structural materials are an important tool in the safe and efficient design of nuclear fusion reactors. Manganese is an important material because of low activation property for fusion reactors. Thus, the manganese metal is commonly used as a key component of many important alloys. And also, it is considered as the shielding materials for nuclear fusion reactor. In the present paper, the excitation functions of neutron and proton induced reactions on fusion structural material Manganese have been calculated by using Hybrid, Geometry Dependent Hybrid and Weisskopf Ewing models. In addition, the different nuclear level density models were tested such as Fermi Gas model with an energy independent level density parameter, and Fermi Gas model of Ignatyuk, Smirenkin, Tishin with an energy dependent level density parameter, and Superfluid nuclear model, and Kataria–Ramamurthy Fermi Gas model. The obtained theoretical cross section calculations in the framework of these nuclear models have been compared with the each other and, the experimental data and TENDL-2014 library. Finally, it seemed that the nuclear cross section calculations are quite sensitive to level densities for nucleon induced reactions.

Theoretical approach to study the light particles induced production routes of 22Na

To create a roadmap for the industrial-scale production of sodium-22, various production routes of this radioisotope involving light charged-particle-induced reactions at the bombarding energy range of threshold to a maximum of 100MeV have been calculated. The excitation functions are calculated by using various nuclear models. Reaction pre-equilibrium process calculations have been made in the framework of the hybrid and geometry dependent hybrid models using ALICE/ASH code, and in the framework of the exciton model using TALYS-1.4 code. To calculate the compound nucleus evaporation process, both Weisskopf–Ewing and Hauser–Feshbach theories have been employed. The cross sections have also separately been estimated with five different level density models at the whole projectile energies. A comparison with calculations based on the codes, on one hand, and experimental data, on the other hand, is arranged and discussed.

Theoretical Predictions of Excitation Functions of Neutron-Induced Reactions on 6Li, 9Be, 12C and 23Na Nuclei at Low Energies

In the present work, the excitation functions of neutron reactions 6Li(n,p)6He, 9Be(n,α)6He, 12C(n,p)12B, 12C(n,α)9Be, 23Na(n,p)23Ne, 23Na(n,2n)22Na and 23Na(n,α)20F produced by the incident neutrons were studied for the investigation of fusion structural materials. Tel et al. formulae (for sodium isotopes), the codes ALICE–ASH and CEM03.01 (for all nuclei) were employed for the obtaining of cross-sections. In addition, hybrid model and geometry-dependent hybrid model with pre-equilibrium emissions, and Weisskopf Ewing model with the equilibrium emissions, and the cascade-exciton model with cascade interactions were used to calculate the excitations curves. The obtained results and Tendl-2011 library data were compared with the experimental literature values. Finally it is to mention that the cross-section data obtained may be useful for the safety design of future fusion reactors.