The presentation presents a part of the work carried out in the research contract No. 24284 titled “accuracy evaluation of available fission yield data and updating” under the umbrella of the Coordinated Research Project (CRP): “updating fission yield data for applications” organized by the International Atomic Energy Agency (IAEA). One of the main objectives of this project is to evaluate the...
Neutron-induced reactions on chlorine isotopes have recently been analyzed in a Hauser-Feshbach framework at Los Alamos National Laboratory. Particular focus has been applied to the "fast" energy range above 100 keV, where these reactions become important for applications like CLYC detector characterization and the development of molten chloride fast reactors (MCFRs). However, challenges to...
Photonuclear reaction cross-section data are required for wide-range applications, such as electron accelerator shielding design and possibly nuclear transmutation. So far, the nuclear data libraries, such as JENDL [1], TENDL [2], and ENDF [3], of various target materials have been prepared up to a photon energy of 200 MeV. To establish the libraries, almost all evaluations have been conducted...
The energy distribution of compound states populated by nuclear muon capture can facilitate understanding the reaction mechanism. We developed a new method, called the in-beam activation method, to measure the production probability of residual nuclei by muon capture. In the method, decaying $\gamma$ rays are measured simultaneously with beam irradiation by exploiting the time structure of the...
We have optimized the optical model potential (OMP) parameters for nucleons (protons and neutrons) induced reaction on 40Ca using the OPTMAN code [1] available on the RIPL-3 data library [2]. The potentials, geometrical and nuclear deformation parameters were extracted via fitting angular distribution data for protons/neutrons elastic and inelastic scattering (Ep,n = 0 – 200 MeV) taken from...
Scattering kernels are more complicated to evaluate than absorption processes due to the fact that scattering procedures involve not only the internal structure of the target nuclei but also the free “classical” particle interacting and emitted from the target. Strictly speaking, the interaction within the nucleus is based on quantum mechanical considerations whereas the emitted particle...
Decay properties of nuclear states in the domain of high nuclear level density (NLD) are usually described within the statistical model of the nucleus using the NLD and photon strength functions (PSFs). In some nuclei with mass $A\sim 30-100$, the NLD might still be insufficiently low even near the neutron separation energy $S_n$. Despite this, the statistical model is used to describe the...
The charge radii in neutron-rich isotopes of Mo, Sr, and Zr have been experimentally shown to suddenly increase at N=58-60 due to a prolate-to-oblate transition, indicating a significant shape evolution. The giant resonance structure has been observed in photonuclear reaction experiments and in measuring the photo-absorption cross sections. For spherical nuclei, a single Lorentzian curve is...
Authors: Miodrag Krmar 1, Rade Smolović 1 , Nikola Jovančević 1
1 Faculty of Science, University of Novi Sad, Novi Sad, Serbia
The cross section values for the 209Bi(γ,xn) nuclear reactions are calculated using the different models for the level density and the radiation strength function by the TALYS code [1]. Based on the obtained data, the yields of nuclear reactions are determined....
Electromagnetic response of the nucleus is characterized by level density and photon strength functions – two key ingredients for modeling statistical gamma decay. Knowledge of these quantities is crucial for our understanding of neutron capture reactions occurring in stars, responsible for nucleosynthesis of heavy elements. The so-called pygmy resonance in photon strength function has emerged...
We derive the fully self-consistent quasiparticle random-phase
approximation (QRPA) equations with noniterative finite amplitude
methods and calculate the transition strengths of giant resonances.
Then, we apply the QRPA results to both neutron radiative capture
calculations based on the statistical Hauser-Feshbach theory and
inelastic scattering calculations based on distorted-wave...
Among the prospective nuclear reactor-produced radionuclides, ytterbium-175 (175Yb) is found to be suitable for the preparation of therapeutic radiopharmaceuticals due to its decay characteristics (T1/2 (4.18d), Emax (480 keV)). It is an important metal that belongs to the rare earth metal family. However, a major constraint for its production via the (n, γ) reaction is the presence of...
With the syntheses of elements up to oganesson (Z = 118), all the fusion evaporation reactions using the 48Ca beams on deformed actinide targets have already been performed. Due to the lack of target material beyond the californium, the use of 50Ti, 51V, and 54Cr is now becoming mandatory to access elements beyond the oganesson (Z = 118). In the SHE mass region, these beams have only been used...
The R-matrix formalism provides an elegant tool for the description of resonant reaction cross sections. Albeit not microscopically based it is widely used because it satisfies conservation rules and yields consistent sets of reaction cross sections. However, R-Matrix theory is limited to two-body channels, while approximations are frequently required for the description of capture and breakup...
Modern time-dependent density functional theory (TDDFT) codes (see e.g. [Comput. Phys. Commun. 229, 211 (2018)][1]) can be used to describe the excited states of nuclei via a number of reaction mechanisms: Through external multipole field excitation, Coulomb scattering, as fission fragments, in heavy ion collisions from around the Coulomb barrier up to deep-inelastic regimes, and via...
In this study, we utilized the Total Monte Carlo (TMC) methodology to simulate the de-excitation process of primary fission fragments in GEF and TALYS. Our primary goal was to establish a framework for evaluating model deficiencies and parameter sensitivities in fission models. As a proof-of-principle we systematically varied the input fission fragment data in TALYS using the GEF code,...
To synthesize a new superheavy element, Z=119, the RIKEN Nishina Center (RNC) upgraded the existing heavy ion linac system (called RILAC) by partially replacing the superconducting linear accelerator (SRILAC) to increase the final beam energy from 5.5 MeV/u to 6.5 MeV/u, enabling a hot fusion reaction of 51V+248Cm. The new Superconducting Electron Cyclotron Resonance Ion Source (SC-ECRIS),...
Plutonium isotopes are produced in nuclear reactors by neutron-induced fission of 235,238U nuclei and by (n,2n), (gamma,n) processes of Neptunium isotopes. Among the Plutonium isotopes, 236Pu nucleus is a trace element of interest for studies of the environmental impact of fuel cycles. Development of new type of fast neutron nuclear reactions destined for scientific researches based on 237Np...
Transmission coefficients describe the probability that a micro-particle will pass through a potential barrier. Using a quantum mechanical approach, the reflection factor is used to calculate the transmission coefficients for charged and neutral particles. Logarithmic derivative is calculated using a rectangular potential in the internal region. With a computer code developed by the authors,...
The properties of nuclear excitations, particularly collective excitation modes such as the giant resonance (GR) and pygmy resonance (PR), can reveal important characteristics of the underlying nuclear structure. The successful description of the nuclear excitations will enable the complete modelling of transitions between their ground and excited states and, furthermore, produce inputs for...
The reason for studying the neutron capture reaction on the mono-isotopic element thulium is twofold. Its only stable isotope, $^{169}$Tm, is often used as a neutron-flux activation monitor. The neutron capture cross-section in the relevant energy range has been measured several times [1-4] in the past and more recently at CSNS [5]. While these data show rough agreement, there are...
History, development and main achievements in sixteen years of the Neutron Activation Analysis based method used for the establishment of the nuclear database at CNESTEN Morocco.
Hamid. Bounouira1*, Hamid. Amsil1, Abdessamad. Didi1, Iliasse. Aarab1, and Abdelwahab. Badague1
1 National Center of Energy, Sciences and Nuclear Techniques (CNESTEN), Morocco
*E-mail: bounouira2000@gmail.com...
V. Alcayne1, D. Cano-Ott1, E. González-Romero1, T. Martı́nez1, E. Mendoza1, A. Pérez de Rada Fiol1, A. Sánchez-Caballero1, J. Balibrea-Correa2, F. Calviño3, R. Capote4, A. Casanovas3, C. Domingo-Pardo2, J. Lerendegui-Marco2 and the n_TOF collaboration.
1 Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Spain
2 Insituto de Fı́sica Corpuscular, CSIC -...
The first measurement of 91Zr(n,a)88Sr reaction cross sections [1], performed in the 3.9–5.3 MeV incident–energy range, followed the need of reliable nuclear data for the isotopes of zirconium used in the blanked and first wall of fusion reactors while the related evaluated data changed by up to 6.4 times were found in widely used libraries. The alpha-particle optical model potential (OMP) was...
Porter-Thomas fluctuations of neutron widths are known to skew compound nuclear decay probabilities away from their statistical, Hauser-Feshbach values. For Hauser-Feshbach codes, the common remedy is to apply the width-fluctuation correction factor of Moldauer, or similar, which accounts for correlations between the entrance and exit channels. For more exotic reactions like beta-delayed...
The VElocity foR Direct particle Identification (VERDI) is a fission-fragment spectrometer based on the detection of velocities as well as energies of fission fragments (2E-2v method). It aims at determining fission yield mass distributions with a resolution of at least A/$\Delta$A = 100. VERDI includes two time-of-flight (TOF) sections, each equipped with a micro-channel plate (MCP) and up to...
One of the challenges of nuclear astrophysics is understanding the observed abundances of the p-process nuclei. Nucleosynthesis simulations typically employ an extended reaction network involving tens of thousands of reactions and thousands of isotopes. As it is impossible to directly measure such a vast number of reactions, simulations rely heavily on calculated cross-sections derived from...
When a negative muon stops in matter, it is captured into an atomic orbit, and subsequently, it is captured by the atomic nucleus at a certain probability through the weak interaction [1]. This process is known as muon nuclear capture ($\mu$NC). In this process, most of the muon's rest energy is carried away by a muon neutrino and the remainder is used to excite the residual nucleus. This...
The National Ignition Facility (NIF) laser at Lawrence Livermore National Laboratory is capable of producing a plasma environment with temperatures ~10 keV, particle densities ~1032 m-3, and neutron fluxes of up to 1034 m-2 s-1. These features, combined with the advanced x-ray, neutron and radiochemistry diagnostics that are available at...
In the reactions induced by weakly bound, tightly bound heavy ions and radioactive ion beams, Incomplete fusion (ICF) dynamics has been an issue of prime interest among nuclear physicists over past decade. The studies with projectiles having alpha structure like 12C, 16O and 20Ne has established the onset of ICF dynamics at energy as low up to Coulomb barrier. Exclusive entrance channel...
