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

Giant dipole resonance parameters optimization and photo-neutron cross-section calculations of several spherical and deformed nuclei

Understanding the interaction between photons and matter is crucial for exploring essential questions in nuclear physics. The Giant Dipole Resonance (GDR) is the prevailing mechanism in photo-absorption cross-sections up to 30 MeV. Depending on whether the nucleus is spherical or deformed, the curve of the photo-absorption cross-section versus photon energy is characterized by one or several Lorentzian peaks. Theoretical calculations of photo-absorption cross-sections are largely centered on deducing GDR parameters. These parameters are used in theoretical reaction codes that aim to simulate photon-induced nuclear reactions accurately. In this study, the GDR parameters for the spherical isotopes 115In, 144Sm, 148Sm, 150Sm, and for the deformed isotopes 154Sm, 153Eu, and 160Gd were calculated by optimizing to the experimental data. The calculated GDR parameters were inputted into the TALYS 1.8 code to compute the photo-neutron cross sections, which were then compared with experimental results from the literature. It has been observed that the calculations performed with the obtained GDR parameters are consistent with the experimental data.

A study on neutron emission for proton-induced reactions in 90Zr, 91Zr, and 115In isotopes

Fusion energy heralds the potential of a transformative era, offering a significant solution to global challenges such as climate change, ozone depletion and environmental pollution. Despite its promising prospects, the commercialization of fusion faces several challenges, including high temperature, pressure, plasma stability, fuel supply, costs, etc. It is important to effectively analyze material behavior under plasma conditions, especially in environments where fusion reactions produce high-energy particles such as neutrons. This study investigates the angle-dependent neutron production mechanisms of proton-induced reactions involving the isotopes 90Zr, 91Zr and 115In, which are widely used in fusion reactor materials. Using the Monte Carlo codes PHITS 3.32 and FLUKA, as well as the TALYS 1.96 code, double differential cross-section calculations for neutron emission were performed considering various angles. The research contributes to a broader understanding of fusion processes by providing insights into the behavior of these isotopes under proton-induced reactions.

A new empirical formula for calculation of (n,3n) cross sections of heavy mass nuclei in the energy region 22-27.5 MeV

In this paper we want to study (n,3n) reactions using an empirical formula derived on the basis of the statistical model considering reaction Q-value dependence. This formula was obtained by taking into account the exponential dependence on asymmetry parameter (N-Z)/A for neutron-induced reactions in Levkovskii's empirical formula. In addition, the present formula depends also on incident energy En, reaction Q-value and symmetry term (N-Z)2/A. Herein, a new analysis of experimental data of (n,3n) reactions in the energy region 22-27.5 MeV was carried out for quick estimation of cross sections of the heavy mass isotopes of odd Z-even N nuclides in the region of A = 151 to 209. We observed a good agreement of the experimental cross section data with the calculations performed using the present empirical formula.

Systematic analysis of (n,3He) reaction cross sections at 14-15 MeV

Numerous research endeavours have delved into comprehending the dynamics of the (n,3He) reaction cross sections. In this study, a novel and straightforward empirical formula is put forth, aimed at swiftly computing the cross sections of the (n,3He) reaction in the neutron energy range of 14-15 MeV. This new formula has been obtained using outcomes from pre-existing cross section formulas in conjunction with experimental data. The present formulation, hinging on the interplay of A23 parameter, threshold energy (Eth) and incident neutron energy (En) factors, appears to furnish a satisfactory methodology for elucidating the cross sections of the neutron-induced (n,3He) nuclear reaction at 14-15 MeV. Finally, in this paper, a comparison is made between the results of the empirical formula and the experiment.

Empirical formula for (n, f) reaction cross sections of Uranium isotopes at 1-20 MeV neutrons

This article describes how to calculate neutron-induced fission reaction cross sections using a proposed empirical formula and the EMPIRE 3.2.3 and TALYS 1.95 computer codes for Uranium isotopes up to the third fission plateau. In this study, the excitation functions of 232U (n, f), 233U (n, f), 234U (n, f), 235U (n, f), 236U (n, f), 237U (n, f) and 238U (n, f) nuclear reactions were calculated at 1-20 MeV neutron energies. The results were contrasted to measured values from the Experimental Nuclear Reaction Data (EXFOR) as well as the evaluated data from Evaluated Nuclear Data File (ENDF) such as (EAF-2010, JEFF-3.3, ENDF/B-VIII.0 and TENDL-2019). Overall, the calculated, experimental, and evaluated fission cross-sections are in concordance.

(n,2n) cross section calculations for tungsten, tantalum and osmium nuclei

Tungsten, tantalum and osmium are important alloying elements in the nuclear technology research and development, particularly in nuclear fission/fusion power plant material applications. So, data results of the cross sections and emission spectra of neutron-induced reactions are required to predict nuclear responses in these elements. However, the cross sections measurements of (n,2n) reactions on tungsten, tantalum and osmium isotopes are rather limited in the literature. In this case, theoretical approaches are often used for obtaining the cross section data. In this article, theoretical (n,2n) cross sections on 180,182-184,186W, 181Ta and 186,192Os target nuclei are calculated up to 20 MeV energy, using the simulation codes TALYS 1.95, ALICE/ASH and CEM03.01. Further, the empirical (n,2n) systematics based on the statistical model have been used for predicting the cross section data at ∼14 MeV incident neutrons. The present results from the empirical systematics and model-based calculations are also compared with the literature experimental data, and JENDL-5.0, ENDF/B-VIII, JEFF3.3 and TENDL-2021 libraries. This paper can provide a contribution to complete description of the (n,2n) reactions considering the lack of experimental cross section data.

New semi-empirical formulae for (n,d) cross sections at 14-15 MeV

The aim of this letter is to suggest new semi-empirical formulae for the prediction of (n,d) cross sections with a neutron energy of 14-15 MeV. In this context, the cross sections are calculated using systematic that is function only of the reaction Q-value and mass number A. The (n,d) reactions are analyzed by using the systematics based on the statistical theory. Thus, the present semi-empirical formulae compared with the cross section data in literature give a good fit for the prediction of the (n,d) cross sections at 14-15 MeV.

Neutron-induced mass shift of tin isotopes recognized using inductively coupled plasma mass spectrometry as an isotopic fingerprint on neutron reactions

The phenomenon of isotope shift in response to neutron irradiation was investigated. The high fission-neutron fluence of 1.44×10¹⁸ cm^-2 from the second Egyptian research reactor (ETRR-2) was used to induce a mass shift in a metallic tin sample. A triple-quadrupole inductively coupled plasma mass spectrometry system was used to analyze the isotope abundances in the mass range from A=111 to A=125. The problem of mass bias due to kinetic fractionation on use of the inductively coupled plasma mass spectrometry system was treated by our calibrating the mass bias with a standard reference tin solution and building a response function. The response function was used to obtain absolute abundances in each mass range instead of isotope ratios. The results show that the mass shifts in the irradiated sample are dependent on the cross section of the neutron capture reaction in the tin isotopes.

Study of cross sections for (n,p) reactions on Hf, Ta and W isotopes

In the nuclear energy applications, hafnium, tantalum and tungsten are desirable materials in the production of super alloys for design of a nuclear power plant. In this study, cross sections calculations via TALYS-1.95, CEM03.01 and ALICE/ASH codes on ¹⁷⁹Hf(n,p)¹⁷⁹Lu, ¹⁸⁰Hf(n,p)¹⁸⁰Lu, ¹⁸¹Ta(n,p)¹⁸¹Hf, ¹⁸²W(n,p)¹⁸²Ta, ¹⁸³W(n,p)¹⁸³Ta, ¹⁸⁴W(n,p)¹⁸⁴Ta and ¹⁸⁶W(n,p)¹⁸⁶Ta reactions were carried out to determine the effects of various level density models and pre-equilibrium models on excitation functions. Besides, we presented our calculation results using the different empirical systematics at 14.5 MeV. The present results are also compared with the experimental and the evaluated nuclear cross section data from TENDL-2019 and JEFF-3.3.

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.

Excitation functions of the Zn(p,xn)Ga reactions

The excitation functions for ^{64,66,67,68,70}Zn(p,n)^{64,66,67,68,70}Ga and ^{64,66,67,68,70}Zn(p,2n)^{63,65,66,67,69}Ga have been calculated for incident proton energies from threshold values to 30 MeV using the statistical model code TALYS-1.6. The (p,n) and (p,2n) cross sections have been calculated using both phenomenological Koning and Delaroche (KD) and semimicroscopic Jeukenne-Lejeune-Mahaux-Bruyeres (JLMB) optical model potentials. The phenomenological back-shifted Fermi gas model (BFM) and microscopic Hartree-Fock (HF) approaches for calculation of level densities have been compared in the present work. The pre-equilibrium process has been treated using exciton model. The sensitivity of cross section data to different models of optical model potential and level density have been investigated. It is found that the (p,n) and (p,2n) cross section calculations with semimicroscopic JLMB optical model potential and microscopic HF level density show agreement with the data. The (p,n) and (p,2n) cross section calculations have been compared with corresponding cross sections from nuclear data library, TENDL-2019. The (p,xn) cross sections obtained will be useful in several applications, particularly, for optimization of production routes for Ga isotopes.

Production assessment of non-carrier-added 199Au by (n,γ) reaction

Gold-199 is a promising theranostic radionuclide for targeted radioimmunotherapy as well as for scintigraphy and dosimetry. ¹⁹⁹Au can be produced in two methods in the direct and indirect routes of the reactor production via ¹⁹⁷Au(n,γ)¹⁹⁸Au(n,γ)¹⁹⁹Au as the direct or ¹⁹⁸Pt(n,γ)¹⁹⁹Pt→¹⁹⁹Au as the indirect method. This investigation described the development of a method for the reactor production of no-carrier-added (NCA) ¹⁹⁹Au through neutron activation of natural Pt in Tehran Research Reactor (TRR) at a thermal neutron flux of 3.5 × 10¹³ n cm^-2 s^-1. Also, in this paper, the activity of ¹⁹⁹Au has been estimated using the MCNPX code. In this case, first, the reactor core is simulated. Then the calculated results are compared with the corresponding experimental values. Moreover, two different chemical separation methods are investigated experimentally in details.

64Cu, a powerful positron emitter for immunoimaging and theranostic: Production via natZnO and natZnO-NPs

⁶⁴Cu is one of the most beneficial radionuclide that can be used as a theranostic agent in Positron Emission Tomography (PET) imaging. In this current work, ⁶⁴Cu was produced with zinc oxide nanoparticles (^natZnONPs) and zinc oxide powder (^natZnO) via the ⁶⁴Zn(n,p)⁶⁴Cu reaction in Tehran Research Reactor (TRR) and the activity values were compared with each other. The theoretical activity of ⁶⁴Cu also was calculated with MCNPX-2.6 and the cross sections of this reaction were calculated by using TALYS-1.8, EMPIRE-3.2.2 and ALICE/ASH nuclear codes and were compared with experimental values. Transmission Electronic Microscopy (TEM), Scanning Electronic Microscopy (SEM) and X-Ray Diffraction (XRD) analysis were used for samples characterizations. From these results, it's concluded that ⁶⁴Cu activity value with nanoscale target was achieved more than the bulk state target and had a good adaptation with the MCNPX result.