scholarly journals Importance of α-induced reactions and the inverse (γ,α) process on p-nuclei

2019 ◽  
Vol 34 (38) ◽  
pp. 1950318
Author(s):  
Chirashree Lahiri
Keyword(s):  
Cross Sections ◽  
Mean Field ◽  
Reaction Rates ◽  
Nucleon Nucleon ◽  
Reaction Cross ◽  
Relativistic Mean Field ◽  
Density Distributions ◽  
Nucleon Nucleon Interaction ◽  
Double Folding ◽  
Microscopic Optical Potential

We have calculated astrophysical reaction cross-sections for [Formula: see text] reactions of some nuclei important for the calculation of p-process reaction-decay network. Reaction rates for [Formula: see text]-induced reactions are calculated with the semi-microscopic optical potential constructed using double folding method, where nuclear density distributions for finite nuclei along with the effective nucleon–nucleon interaction are the important components of the folded potential. For this purpose, density distributions of target nuclei are obtained from relativistic mean field approach. Astrophysical reaction cross-section for elastic scattering of [Formula: see text]-particle from [Formula: see text] target is compared with the existing experimental results to constrain the newly formed potential. Further, to check the credibility of the present theoretical framework, the astrophysical S-factor for [Formula: see text] reactions are compared with the experimental observation, wherever available. Finally, an estimate of dominant photodisintegration channels at various astrophysical temperature is discussed for p-nuclei [Formula: see text] and [Formula: see text].

Nuclear mean free paths and transparency at intermediate energies

1983 ◽  
Vol 61 (4) ◽  
pp. 750-753 ◽  
Author(s):  
Paul J. Karol
Keyword(s):  
Cross Sections ◽  
Nucleon Nucleon ◽  
Reaction Cross ◽  
Uniform Density ◽  
Nucleon Interaction ◽  
Density Distributions ◽  
Intermediate Energies ◽  
Soft Spheres ◽  
Nucleon Nucleon Interaction ◽  
Reaction Cross Sections

The soft-spheres model of nuclear reaction cross sections incorporating tapered density distributions is used to evaluate nucleon mean free paths and transparencies at intermediate energies. Comparison with similar calculations employing uniform density distributions shows the latter to give misleading results that nevertheless have been used in recent years as evidence that the physics of the nucleon–nucleon interaction within nuclei is incompletely understood.

MICROSCOPIC NUCLEON–NUCLEUS OPTICAL POTENTIAL WITH REARRANGEMENT EFFECTS BASED ON THE EFFECTIVE SKYRME FORCES

2009 ◽  
Vol 18 (09) ◽  
pp. 1845-1862 ◽  
Author(s):  
V. V. PILIPENKO ◽  
V. I. KUPRIKOV ◽  
A. P. SOZNIK
Keyword(s):  
Cross Sections ◽  
Optical Potential ◽  
Nucleon Nucleon ◽  
Reaction Cross ◽  
Effective Density ◽  
Elastic Neutron ◽  
Calculation Results ◽  
Nucleon Nucleon Interaction ◽  
Reasonable Description ◽  
Microscopic Optical Potential

The nucleon scattering on even–even nuclei in the medium-energy region has been analyzed on the basis of microscopic optical potential (OP) obtained from nuclear-matter calculations with using effective density-dependent nucleon–nucleon interaction of Skyrme type with taking account of the rearrangement potential. Calculations have been performed for volume integrals and rms radii of nucleon–nucleus OP, for energy dependencies of total and total reaction cross sections of neutron– and proton–nucleus scattering and for differential cross sections of the elastic neutron scattering at several energies on various target nuclei. Comparison of the calculation results for the mentioned quantities with corresponding experimental data has been carried out, which has shown a principal possibility of their reasonable description in the framework of the model under consideration.

scholarly journals IMPORTANCE OF Q-VALUES IN ASTROPHYSICAL RAPID PROTON CAPTURE PROCESS

2013 ◽  
Vol 28 (17) ◽  
pp. 1350076 ◽  
Author(s):  
CHIRASHREE LAHIRI ◽  
G. GANGOPADHYAY
Keyword(s):  
Optical Model ◽  
Mean Field ◽  
Reaction Rates ◽  
Nucleon Nucleon ◽  
Proton Capture ◽  
Capture Process ◽  
Relativistic Mean Field ◽  
Rapid Proton ◽  
Nucleon Nucleon Interaction ◽  
Q Values

The importance of measuring Q-values in rapid proton capture process has been investigated. The microscopic optical model, derived using a nucleon–nucleon interaction and densities from relativistic mean field (RMF) calculations, has been utilized to calculate the reaction rates. It has been observed that the Q-values involved in the reactions at waiting points at A = 60 and 64 are very important in determining the final abundance of the process. Some other Q-values also play a crucial role in the final abundance of nuclei near the end point of the process.

Analysis with SDHO and RMF density distributions of elastic scattering cross-sections of oxygen isotopes (16–18O) by various target nuclei

2018 ◽  
Vol 27 (07) ◽  
pp. 1850055 ◽  
Author(s):  
M. Aygun
Keyword(s):  
Elastic Scattering ◽  
Oxygen Isotopes ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Mean Field ◽  
Relativistic Mean Field ◽  
Density Distributions ◽  
Scattering Cross ◽  
Double Folding ◽  
Scattering Cross Sections

In the present study, two different density distributions of oxygen isotopes ([Formula: see text]O) that consist of the harmonic oscillator single-particle wave functions (SDHO) and the relativistic mean-field (RMF) approaches are investigated for the availability of elastic scattering cross-sections. For this purpose, the elastic scattering angular distributions of nuclear reactions with 13 target nuclei, four target nuclei and nine target nuclei are calculated for [Formula: see text]O, [Formula: see text]O and [Formula: see text]O, respectively. For these calculations, the double folding model based on the optical model is used. The optical potential parameters, volume integrals and cross-sections for all the nuclear reactions are given in this study. The comparison of theoretical results and experimental data shows very good agreement. The imaginary potential depth expressions, which will be new and more practical terms to explain the nuclear interactions of [Formula: see text]O, [Formula: see text]O and [Formula: see text]O with different nuclei, for each oxygen isotope are proposed.

scholarly journals Elastic scattering of one-proton halo nucleus 17F on different mass targets using semi microscopic potentials

2019 ◽  
Vol 65 (2) ◽  
pp. 168 ◽  
Author(s):  
Awad A. Ibraheem ◽  
Arwa S. Al-Hajjaji ◽  
And M. El-Azab Farid
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Nucleon Nucleon ◽  
Model Potential ◽  
Reaction Cross ◽  
Optical Model Potential ◽  
Nucleon Nucleon Interaction ◽  
Double Folding ◽  
Reaction Cross Sections ◽  
Proton Halo

The elastic scattering of 17F have been studied for different mass targets (e.g. 12C, 14N, 58Ni, 208Pb) at different energies. We used the double folding optical model potential based on the density-dependent DDM3Y effective nucleon-nucleon interaction. Both version of the density distribution of the one-proton halo 17F nucleus has been taken into account in the above mentioned potential. The data for angular distributions of the elastic scattering differential cross section and reaction cross sections has been successfully reproduced at different energies using the above potentials. The energy dependence and the target mass number dependence of scattering in the imaginary volume integrals and the total reaction cross sections has also been studied.

scholarly journals Microscopic optical potentials for Li isotopes

2020 ◽  
Vol 239 ◽  
pp. 03016
Author(s):  
Wendi Chen ◽  
Hairui Guo ◽  
Weili Sun ◽  
Tao Ye ◽  
Yinlu Han ◽  
...  
Keyword(s):  
Internal Wave ◽  
Cross Sections ◽  
Optical Potential ◽  
Effective Interaction ◽  
Nucleon Nucleon ◽  
Reaction Cross ◽  
Wave Functions ◽  
Density Distributions ◽  
Optical Potentials ◽  
Microscopic Optical Potential

The microscopic optical potentials for Li isotopes (A=6,7) without free parameter are obtained by folding the microscopic optical potentials of their internal nucleons with density distributions generated from corresponding internal wave functions of Li isotopes. An isospin-dependent nucleon microscopic optical potential based on the Skyrme nucleon-nucleon effective interaction is used as the nucleon optical potential. Shell model is employed to construct the internal wave functions of Li isotopes and derive their density distributions of internal nucleons. The Li microscopic optical potentials are used to calculate the elastic-scattering angular distributions and reaction cross sections. The results reproduce experimental data well and are comparable to those calculated by phenomenological optical model potentials in many cases.

DENSITY-DEPENDENT CLUSTER MODEL OF α DECAY

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2365-2368 ◽  
Author(s):  
CHANG XU ◽  
ZHONGZHOU REN
Keyword(s):  
Nuclear Physics ◽  
Cluster Model ◽  
Daughter Nucleus ◽  
Nucleon Nucleon ◽  
Nucleon Interaction ◽  
Α Decay ◽  
Density Dependent ◽  
Density Distributions ◽  
Nucleon Nucleon Interaction ◽  
Double Folding

A new cluster model of α decay is proposed where the effective potential between α-cluster and daughter nucleus is obtained from the double folding integral of the renormalized M3Y nucleon-nucleon interaction and of the density distributions of α particle and daughter nucleus. Without introducing any extra adjustment on the potential, the new model (named as the density-dependent cluster model) can successfully reproduce the experimental half-lives of α decay within a factor of 3. The model also works well for new superheavy elements which are the current interests of nuclear physics and chemistry.

Multi-interaction of multi-nucleon transfer reactions in the whole-angle region

1996 ◽  
Vol 74 (3-4) ◽  
pp. 150-154 ◽  
Author(s):  
A. A. Farra
Keyword(s):  
Cross Sections ◽  
Exchange Process ◽  
Heavy Ion ◽  
Nucleon Nucleon ◽  
Transfer Reactions ◽  
Ion Transfer ◽  
Exchange Processes ◽  
Nucleon Nucleon Interaction ◽  
Double Folding ◽  
Good Agreement

Heavy-ion transfer reactions are studied using the exact finite-range DWBA (distorted wave Born approximation) calculations. To investigate the differential cross sections in the whole-angle region the reaction mechanism is considered as a coherent sum of direct and exchange processes. Both the double-folding microscopic nucleon–nucleon interaction and phenomenological Woods–Saxon form are used for the real and imaginary distorting potentials in the initial and final channels, respectively. The present calculations are in good agreement with the experimental data in the whole angular range. The inclusion of the exchange process improves the cross section's magnitude explicitly and leads to a better description of the backward oscillations. The values of the extracted normalization coefficients obtained are reasonable.

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