EXTENDED OPTICAL MODEL ANALYSES FOR 9Be + 144Sm SYSTEM NEAR COULOMB BARRIER ENERGIES

2011 ◽  
Vol 26 (05) ◽  
pp. 325-336 ◽  
Author(s):  
W. Y. SO ◽  
K. S. KIM
Keyword(s):  
Elastic Scattering ◽  
Cross Section ◽  
Cross Sections ◽  
Coulomb Barrier ◽  
Optical Model ◽  
Fusion Cross Section ◽  
Reaction Cross ◽  
Direct Reaction ◽  
Cross Section Data ◽  
Section Data

Within the framework of an extended optical model, we study elastic scattering and fusion cross section data for 9 Be + 144 Sm system near Coulomb barrier energies to determine the polarization potential decomposed into direct reaction and fusion parts. We show that the direct reaction and fusion potentials extracted from χ2 analyses separately satisfy the dispersion relation and that the threshold anomaly exhibits in the fusion part. The analyses using only elastic scattering and fusion data can furnish very consistent and reliable predictions of cross sections even though the direct reaction cross section data are not enough. From these analyses, we also obtain the semi-experimental α single and α–α coincidence cross sections, [Formula: see text] and [Formula: see text], for 9 Be + 144 Sm system.

scholarly journals Analysis of the fusion cross sections for 16,18,20O + 12C systems at low energies

2019 ◽  
Vol 97 (7) ◽  
pp. 803-807 ◽  
Author(s):  
G. Kocak
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Optical Model ◽  
Fusion Cross Section ◽  
Nucleon Nucleon ◽  
Cross Section Data ◽  
Section Data ◽  
Low Energies ◽  
Double Folding ◽  
Good Agreement

Fusion cross section data for the 16,18,20O + 12C systems at energies near and below the Coulomb barrier are studied within the framework of the optical model. To examine these reactions, the microscopic nucleon–nucleon double folding potentials for real and imaginary parts are found. To make a comprehensive analysis of the effect of neutron-rich systems, we used three different reactions from stable to unstable systems. The microscopic nucleon–nucleon double folding potentials show very good agreement for 16,18,20O + 12C systems with a very weak imaginary potential. Also, we have obtained better agreement by using fully microscopic nucleon–nucleon double folding potentials with the 20O + 12C system’s experimental data than in previous works, but especially at low energies we still have some problems reproducing the 20O + 12C system’s fusion cross section data.

MICROSCOPIC POTENTIAL DESCRIPTION OF THE ELASTIC SCATTERING AND FUSION CROSS-SECTION DATA OF THE 12C+24Mg SYSTEM

2006 ◽  
Vol 15 (06) ◽  
pp. 1317-1332 ◽  
Author(s):  
M. KARAKOC ◽  
I. BOZTOSUN
Keyword(s):  
Elastic Scattering ◽  
Cross Section ◽  
Fusion Cross Section ◽  
Nucleon Nucleon ◽  
Angular Distributions ◽  
Cross Section Data ◽  
Section Data ◽  
Coupled Channels ◽  
Double Folding ◽  
Detailed Application

This paper comprises the first detailed application of the microscopic potentials for a simultaneous analysis of the elastic scattering and fusion cross-section data of the 12 C+ 24Mg system from 16.0 MeV to 24.0 MeV. We use the microscopic nucleon-nucleon double folding and α-α double folding cluster potentials within the framework of the optical model and coupled-channels formalism. We compare our microscopic potential results with the findings of the phenomenological deep and shallow potentials. All potentials provide a very good agreement with the experimental data for the elastic scattering angular distributions. However, only deep phenomenological, the microscopic nucleon-nucleon and α-α double folding cluster potentials provide a consistent description of the angular distributions and fusion cross-section data simultaneously.

Projectile breakup effects in the fusion dynamics of 6,7Li +144,152Sm reactions around Coulomb barrier

2020 ◽  
Vol 29 (05) ◽  
pp. 2050029
Author(s):  
Manjeet Singh Gautam ◽  
Sukhvinder Duhan ◽  
Rishi Pal Chahal ◽  
Hitender Khatri ◽  
Suman B. Kuhar ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Coulomb Barrier ◽  
Incomplete Fusion ◽  
Complete Fusion ◽  
Cross Section Data ◽  
Suppression Factor ◽  
Model Calculations ◽  
Section Data ◽  
Breakup Channel

This work emphasized the role of the projectile breakup channel by studying the complete fusion (CF) and incomplete fusion (ICF) dynamics of [Formula: see text] reactions. The theoretical calculations for the chosen reactions have been done by opting for the coupled channel approach and the energy dependent Woods–Saxon potential (EDWSP) model. The below barrier fusion enhancements of the studied reactions are reasonably addressed by the outcomes of the adopted models, which in turn can be attributed to the couplings of nuclear structure degrees of freedom of the collision partners to their relative motion. In contrast, at above barrier energies, the CF cross-section data of the chosen reactions are found to be suppressed significantly when compared with the predictions made by using the present models. Interestingly, the fusion suppression factors of the given reactions can be minimized considerably with respect to the reported value when it is analyzed within the framework of the EDWSP model. For instance, in case of [Formula: see text] ([Formula: see text] reaction, the magnitude of fusion suppression factor is minimized up to 7% (13%) relative to the reported value whereas for [Formula: see text] ([Formula: see text] reaction, the fusion suppression factor is found to be less by 7% (8%) with reference to the reported value. Such suppression effects can be correlated with the low breakup threshold of alpha breakup channel associated with the loosely bound projectile. The projectiles being weakly bound systems split into two charged fragments and either of the breakup components is absorbed by the target resulting in the reduction of incoming flux going into fusion channel. The flux lost from the CF channel appears in the form of ICF yields. For [Formula: see text], total fusion (TF) cross-sections that are sum of CF and ICF cross-sections are also analyzed in conjunction with the EDWSP model and thus reasonably explained by the model calculations. In order to identify the ICF contribution, the ratio of ICF/TF cross-section data of [Formula: see text] reaction has been examined and thus properly addressed by using the EDWSP model. The presence of ICF component in TF cross-section clearly pointed out the breakup of projectile due to its loosely bound nature prior to the Coulomb barrier. Although ICF data of other systems are not available in the literature, a similar behavior is expected for ICF and TF data for [Formula: see text] and [Formula: see text] reactions.

scholarly journals The Neutron Facility at NCSR "Demokritos"- Implementation in the Case of the 232Th(n,2n) and 241Am(n,2n) Reactions

2020 ◽  
Vol 13 ◽  
pp. 136
Author(s):  
R. Vlastou ◽  
C. T. Papadopoulos ◽  
G. Perdikakis ◽  
M. Kokkoris ◽  
S. Kossionides ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Computer Code ◽  
Reaction Cross ◽  
Cross Section Data ◽  
Model Calculations ◽  
Section Data ◽  
Neutron Facility ◽  
Mev Protons ◽  
Reaction Cross Sections

In the 5.5 MV tandem T11/25 Accelerator Laboratory of NCSR "Demokritos" monoenergetic neutron beams can be produced in the energy ranges 120-650 keV, 4-11.5 MeV and 16-20.5 MeV by using the 7Li(p,n), 2H(d,n) and 3H(d,n) reactions, respectively. The corresponding beam energies and ions delivered by the accelerator, are 1.92-2.37 MeV protons, 0.8-9.6 MeV deuterons and 0.8-3.7 MeV deuterons, for the three reactions, respectively. Experimental results for neutron energies from threshold up to 11.5 MeV and at 17.1 MeV will be given for the 232Th(n,2n)231Th reaction, while for the 241 Am(n,2n)240 Am reaction, preliminary cross section data at 10.4, 10.6 and 17.1 MeV will be discussed. In the framework of the CERN n-TOF collaboration, the cross section of these reactions have been measured relative to the 197Au(n,2n)196Au, 27Al(n,a)24Na and 93Nb(n,2n) reaction cross sections, by using the activation method. In addition to the experimental work, theoretical Statistical model calculations are being carried out using the computer code STAPRE/F. The results are compared to the experimental data.

The p +9Be elastic scattering below 30MeV: Optical model analysis and data normalization

2021 ◽  
pp. 2150024
Author(s):  
H. M. Maridi ◽  
A. Pakou ◽  
K. Rusek
Keyword(s):  
Elastic Scattering ◽  
Differential Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Differential Cross ◽  
Optical Model ◽  
Reaction Cross ◽  
Data Normalization ◽  
Optical Model Analysis ◽  
Reaction Cross Sections

Differential cross-section data of elastic scattering for [Formula: see text]Be below a proton incident energy of 30[Formula: see text]MeV are evaluated by using two techniques. First, optical model analysis is performed and applied to the analyzing powers and reaction cross-sections to extract the optical potential parameters. Then, angular distributions of the differential cross-section are calculated with this potential and compared with the experimental data and normalization coefficients are extracted. Second, a consistent comparison between data sets with similar energies is considered in a minimization process to obtain another set of data normalization coefficients. The two techniques lead to similar normalized values for the existing data and consistently validate a body of low-energy data that can be safely used for further theoretical studies. Furthermore, the systematic behavior and energy dependence of the volume integral are determined as well as the energy dependence of the reaction cross-sections is predicted.

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