NUCLEAR PHYSICS A

The level density parameters (level density parameter a and energy shift delta) for back-shifted Fermi gas model have been determined for 1136 nuclei for which complete level scheme is available. Level density parameter is calculated by using the semi-classical single particle level density, which can be obtained analytically through spherical harmonic oscillator potential. This method also enables us to analyze the Coulomb potential's effect on the level density parameter. The dependence of this parameter on energy has been also investigated. Another parameter, delta, is determined by fitting of the experimental level scheme and the average resonance spacings for 289 nuclei. Only level scheme is used for optimization procedure for remaining 847 nuclei. Level densities for some nuclei have been calculated by using these parameter values. Obtained results have been compared with the experimental level scheme and the resonance spacing data. (C) 2011 Elsevier B.V. All rights reserved

NUCLEAR SCIENCE AND TECHNIQUES

The experimental elastic cross section data of the projectile Be-11 on target C-12 at 49.3 MeV/nucleon energy is analysed. The calculations for the elastic scattering are performed by the phenomenological optical model. The different optical potentials to include breakup effects into the calculations, which are neutron+C-12, neutron+ Be-10 and Be-10+C-12, are described with the aid of the global potentials for neutron interactions and fitted to experimental data for the core and target interaction. Also, the first analysis of the optical model for Be-10 on target C-12 at 39.1 MeV is done for building the interaction potential of the core and the target for Be-11. For investigating the effects of the spectroscopic factors, obtained factors from the direct capture process using the nuclear level density are compared with the previous cross section and spectroscopic factor results. Obtained results for the elastic cross section reproduce the experimental data very well and show the requirement of including spectroscopic properties such as, spectroscopic factors and density of the excited states, to explain this elastic cross section data

PHYSICAL REVIEW C

The elastic and inelastic cross sections of Li-6 on Si-28 at 240 MeV, and quasielastic cross section of Li-7 and Li-11 on Si-28 at 177.8 and 319 MeV, respectively, are analyzed with the coupled-channels method. The collective nuclear level density is used to determine the deformation parameter regarding to the first-excited state of Si-28. The results are in agreement with the experimental data and indicate the need of using a nuclear structure model such as nuclear level density to reduce the ambiguity between the optical model parameters and the deformation parameter. Additionally, the spin-orbit potential is found to have an important role in reproducing the data of the quasielastic scattering of Li-7 and Li-11 on a Si-28 target

INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS

gamma-ray strength function is the key input for the photonuclear reactions, which have a special astrophysical importance, and should be renormalized by using the nuclear level density for calculating the theoretical average radiative capture width, but performing such renormalization is challenging for light nuclei. With this motivation, recently introduced level density parameter formula including collective effects is used to calculate the average radiative capture width of light nuclei, and therefore to renormalize their gamma-ray strength functions. Obtained normalization factors are tested in (n, gamma) reactions for the necessity of renormalization for light nuclei

EUROPEAN PHYSICAL JOURNAL A

The new definition of the energy dependence for the level density parameter including collective effects depends strongly on the semi-classical approach. For this method, defining an accurate single-particle potential is of great importance. The effect of the single-particle potential terms, which are central, spin-orbit, harmonic oscillator, Woods-Saxon and Coulomb potential, both for spherical and deformed cases, on the level density parameter was investigated by examining the local success of the global parameterizations of eight different combinations of these terms. Among these combinations, the sum of the central, spin-orbit, harmonic oscillator and Coulomb potentials, gives the most accurate predictions compared with experimental data. The local selections of the global parameterizations show that the single-particle models, which are based on the Woods-Saxon potential as the main term, are more suitable candidates than the models based on harmonic oscillator potential to extrapolate away far from stability. Also it can be concluded that the contribution of the Coulomb interaction, both around the closed and open shells is not neglectable

Collective effects in deuteron induced reactions of aluminum

Cross sections of 27 Al(d,x)22 Na, 27 Al(d,x)24 Na, and 27 Al(d,x)27 Mg reactions are calculated by using TALYS 1.6 computer code with different nuclear level density models, which are composite Gilbert–Cameron model, back-shifted Fermi gas model, generalized superfluid model, and recently proposed collective semi-classical Fermi gas model in the energy range of 3–180 MeV. The results are compared with the experimental data taken from EXFOR library. In these deuteron induced reactions, collective effects are investigated by means of nuclear level density models. Collective semi-classical Fermi gas model including the collective effects via the level density parameter represents the best agreement with the experimental data compared to the other level density models, especially in the low deuteron bombarding energies where the collective effects dominate. © 2016 Elsevier B.V

NUBA CONFERENCE SERIES -1: NUCLEAR PHYSICS AND ASTROPHYSICS

The cross sections are calculated for the both elastic and inelastic scattering of He-6 from C-12 and He-4. A phenomenological optical potential is used to describe the elastic scattering. He-4 is taken as spherical and inelastic couplings to the first excited states of He-6 and C-12 are described with collective rotational model and coupled-channels method. Deformation lengths for He-6 and C-12 are determined from semi-classical nuclear level density model by using Laplace-like formula for the nuclear level density parameter. The comparison of the predicted and the measured cross sections are presented to test the applicability of nuclear level density model to the light exotic nuclei reactions. Good agreement is achieved between the predicted and measured cross sections

NUCLEAR PHYSICS A

Collective effects in the level density are not well understood, and including these effects as enhancement factors to the level density does not produce sufficiently consistent predictions of observables. Therefore, collective effects are investigated in the level density parameter instead of treating them as a final factor in the level density. A new Laplace-like formula is proposed for the energy dependence of the level density parameter, including collective effects. A significant improvement has been achieved in agreement between observed and predicted energy levels. This new model can also be used in both structure and reaction calculations of the nuclei far from stability, especially near the drip lines. (C) 2014 Elsevier B.V. All rights reserved

A new proton spectra for

In this paper, we present a new measurement of the inclusive cross section (p,xp) reactions on $$^{nat}\hbox {Cu}$$ at incident energies of $$\hbox {E}_{p}=$$ 7 and 30 MeV. The (p,xp) reaction at $$\hbox {E}_{p}$$= 7 MeV on $$^{nat}\hbox {Cu}$$ is measured for the first time and (p,xp) and ($$\hbox {p,x}\alpha$$) inclusive cross section for the same target at $$\hbox {E}_{p}=$$ 30 MeV is re-measured in order to improve the quality of the previous experimental data. For both energies, the mechanism of the pre-equilibrium reactions as well as the level of energy dependence are discussed and the adequacy of the theoretical models in explaining the newly measured experimental data is also assessed by comparing the experimental data with the results of the Hauser-Feshbach and Exciton models. We use the microscopic approach based on nucleon–nucleon interaction to produce the complex nuclear potential