scholarly journals Role of the shape deformation in 12C + 12C fusion at sub-Coulomb energies

2019 ◽  
Vol 2 (4) ◽  
pp. 112-118
Author(s):  
Chien Hoang Le ◽  
Anh Viet Bui ◽  
Vy Nguyen Ha Thach
Keyword(s):  
Cross Sections ◽  
Surface Deformation ◽  
Good Description ◽  
Fusion Cross Section ◽  
Scattering Data ◽  
Angular Distributions ◽  
The Real ◽  
S Factor ◽  
Barrier Penetration

The fusion cross section of 12C+12C system at the energies of astrophysical interest is calculated in the framework of barrier penetration model taking into account the deformed shape of interacting nuclei. In particular, the quadrupole surface deformation of both projectile and target nuclei has been included during the fusion process. The real and imaginary parts of nucleus-nucleus interactions performed using the Woods-Saxon square and Woods-Saxon functions, respectively have been carefully tested by 12C-12C elastic scattering data analysis before employed to evaluate the astrophysical S factors (the fusion cross sections). The optical model results of elastic angular distributions are consistent with the experimental data. Within the barrier penetration model, the real part of the obtained optical potential gives a good description of the non-resonant astrophysical S factor. It turns out that the taking into account of quadrupole deformation of 12C nuclei increases the astrophysical S factor at energies below Coulomb barrier.

scholarly journals ω AND η (η') MESONS FROM NN AND ND COLLISIONS AT INTERMEDIATE ENERGIES

2010 ◽  
Vol 19 (05n06) ◽  
pp. 894-902 ◽  
Author(s):  
L. P. KAPTARI ◽  
B. KÄMPFER
Keyword(s):  
Cross Sections ◽  
Good Description ◽  
Meson Production ◽  
Form Factors ◽  
Angular Distributions ◽  
Transition Form ◽  
Vector Meson Production ◽  
Intermediate Energies ◽  
Electron Production ◽  
Pseudo Scalar

The production of pseudo scalar, η, η′, and vector, ω, ρ, ϕ, mesons in NN collisions at threshold-near energies is analyzed within a covariant effective meson-nucleon theory. It is shown that a good description of cross sections and angular distributions, for vector meson production, can be accomplished by considering meson and nucleon currents only, while for pseudo scalar production an inclusion of nucleon resonances is needed. The di-electron production from subsequent Dalitz decay of the produced mesons, η′ → γγ* → γe+e- and ω → πγ* → πe+e- is also considered and numerical results are presented for intermediate energies and kinematics of possible experiments with HADES, CLAS and KEK-PS. We argue that the transition form factor ω → γ*π as well as η′ → γ*γ can be defined in a fairly model independent way and the feasibility of an experimental access to transition form factors is discussed.

scholarly journals Experimental measurement of the 12C+16O fusion cross sections at astrophysical energies

2018 ◽  
Vol 178 ◽  
pp. 04008
Author(s):  
X. Fang ◽  
W. P. Tan ◽  
M. Beard ◽  
R. J. deBoer ◽  
G. Gilardy ◽  
...  
Keyword(s):  
Cross Sections ◽  
Center Of Mass ◽  
Model Calculations ◽  
Center Of Mass Energy ◽  
Pure Graphite ◽  
S Factor ◽  
Hpge Detectors ◽  
Low Energies ◽  
The University

The total cross sections of the 12C+16O fusion have been experimentally determined at low energies to investigate the role of this reaction during late stellar evolution burning phases. A high-intensity oxygen beam was produced by the 5MV pelletron accelerator at the University of Notre Dame impinging on a thick ultra-pure graphite target. Protons and γ-rays were measured simultaneously in the center-of-mass energy range from 3.64 to 5.01 MeV, using strip silicon and HPGe detectors. Statistical model calculations were employed to interpret the experimental results. A new broad resonance-like structure is observed for the 12C+16O reaction, and a decreasing trend of its S-factor towards low energies is found.

Dynamics of 16,18O-induced reactions using Ni, Ge and Mo targets

2016 ◽  
Vol 25 (11) ◽  
pp. 1650091 ◽  
Author(s):  
Rajni ◽  
Gurvinder Kaur ◽  
Manoj K. Sharma
Keyword(s):  
Cross Sections ◽  
Fusion Cross Section ◽  
Cluster Decay ◽  
Cross Section Data ◽  
Orientation Degree ◽  
Decay Modes ◽  
Section Data ◽  
Collective Clusterization ◽  
Good Agreement

Dynamical cluster decay model (DCM) based on the collective clusterization approach is employed to explore the dynamics of various even-mass Zr isotopes formed in [Formula: see text]O-induced reactions. In reference to the measured fusion cross-section data, various decay modes contributing towards [Formula: see text]Zr[Formula: see text] nuclei are investigated. Also, the role of deformations and orientation degree of freedom is analyzed by comparing results with spherical choice of fragmentation. In addition to this, the effect of entrance channel is explored for [Formula: see text]Zr[Formula: see text] and [Formula: see text]Kr[Formula: see text] nuclei formed in [Formula: see text]O and [Formula: see text]O-induced reactions. Besides this, the dynamics of relatively heavier mass Sn isotopes is exercised using [Formula: see text]O and [Formula: see text]O projectiles. The DCM calculated decay cross-sections find good agreement with available experimental data.

The effect of breakup of 6Li on elastic scattering and fusion with 28Si at near barrier energies

2016 ◽  
Vol 25 (01) ◽  
pp. 1650003 ◽  
Author(s):  
Mandira Sinha ◽  
Subinit Roy ◽  
P. Basu ◽  
H. Majumdar
Keyword(s):  
Elastic Scattering ◽  
Energy Dependence ◽  
Cross Sections ◽  
Model Potential ◽  
Angular Distributions ◽  
The Real ◽  
Optical Model Potential ◽  
Coupled Channel ◽  
Potential Parameters ◽  
Existing Data

Elastic scattering angular distributions for 6Li+[Formula: see text]Si system were measured at [Formula: see text] and analyzed along with the existing data from the previous measurements in the energy range of [Formula: see text]. The measured cross-sections and the existing data, forming a set of angular distributions over a range of E/[Formula: see text], were analyzed using the phenomenological optical model potential (OMP). Three different sets of potential parameters were used. The energy dependence of the real and the imaginary potential strengths were, subsequently, extracted at the radius of sensitivity ([Formula: see text]) for the system. Continuum Discretized Coupled Channel (CDCC) calculation was performed to explore the contribution of projectile break-up (BU) on the observed energy dependence of the effective potential for elastic scattering of 6Li from [Formula: see text]Si. The energy variation of the strength of the real potential with continuum coupling was found to agree with the energy dependence of the same extracted from the (OMP) analysis at energies around the barrier. But the behavior of the imaginary strength appeared to be different. The calculated fusion cross-sections, including the effect of BU, clearly overestimated the measured fusion excitation function data in the below and near barrier energies but compared well with the data at higher energies.

scholarly journals Analyses of alpha–alpha elastic scattering data in the energy range 53.4–119.9 MeV

2016 ◽  
Vol 94 (1) ◽  
pp. 95-101 ◽  
Author(s):  
Z.F. Shehadeh
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Reaction Cross ◽  
Nucl Phys ◽  
Scattering Data ◽  
Repulsive Core ◽  
The Real ◽  
First Time ◽  
Alpha Elastic Scattering ◽  
Reaction Cross Sections

The differential and reaction cross sections for alpha–alpha elastic scattering at energies ranging from 50 to 120 MeV (lab. system) have been clearly explained for the first time, by using a new optical potential type. This potential, which is different from all other proposed potentials, is composed of two real parts: one is an attractive squared Woods–Saxon and the other is a repulsive core of the Woods–Saxon form in addition to a surface Woods–Saxon form for the imaginary part. The nature of the real part has been determined from available phase shifts through using inverse scattering theory for the identical particles at a fixed energy, adopting the framework of the Schrödinger equation. It is found that the repulsive real part is essential for improving the fit to the measured elastic differential cross sections, and in explaining the kink that appears at r < 1.0 fm in the shape of the real part of the potential. Using this new potential, our calculated reaction cross sections are in reasonable agreement with the ones reported by both Darriulat et al. (Phys. Rev. 137, B315 (1965). doi:10.1103/PhysRev.137.B315) and Brown and Tang (Nucl. Phys. A, 170, 225 (1971). doi:10.1016/0375-9474(71)90633-6 ).

Systematic study of deformation effects on fusion cross-sections using various proximity potentials

Open Physics ◽  
2014 ◽  
Vol 12 (6) ◽  
Author(s):  
Tapan Rajbongshi ◽  
Kushal Kalita
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Cross Sections ◽  
Fusion Cross Section ◽  
Proximity Potential ◽  
Deformation Parameters ◽  
Barrier Penetration ◽  
Experimental Fusion ◽  
Static Quadrupole ◽  
Better Than

AbstractThe influence of static quadrupole and hexadecapole (positive & negative) deformation of targets are studied using eleven different versions of nuclear potentials. The height and position of the interaction barrier for the reactions induced by spherical projectile (16O) on the deformed targets such as 166Er, 154Sm and 176Yb have been estimated. It is found that the nucleus-nucleus potential strongly depends on the value of the deformation parameters and orientation of the target. The experimental fusion cross-section of the reactions 16O + 176Yb, 16O +166Er and 16O +154Sm are investigated by applyingWong’s formula using various parameterizations of the proximity potential as well as an assessment of the results of a multi-dimensional barrier penetration model (BPM). The fusion cross-sections by Prox 77, Prox 88, Prox 00, Prox 00DP, Denisov DP, Bass 80, CW 76 and AW 95 potentials are found to be better than the rest in comparison to experimental data.

scholarly journals FUSION OF LIGHT PROTON-RICH EXOTIC NUCLEI AT NEAR-BARRIER ENERGIES

2002 ◽  
Vol 11 (06) ◽  
pp. 491-500 ◽  
Author(s):  
P. BANERJEE ◽  
K. KRISHAN ◽  
S. BHATTACHARYA ◽  
C. BHATTACHARYA
Keyword(s):  
Cross Sections ◽  
Fusion Cross Section ◽  
Exotic Nuclei ◽  
Complete Fusion ◽  
Coupling Case ◽  
Inelastic Excitation ◽  
The One ◽  
Coupled Channel ◽  
The Continuum

We study, theoretically, the fusion of the light proton-rich exotic nuclei 17 F and 8 B at near-barrier energies in order to investigate the possible role of breakup processes on their fusion cross sections. To this end, coupled channel calculations are performed, considering the couplings to the breakup channels of these projectiles. In case of 17 F , the coupling arising out of the inelastic excitation from the ground state to the bound excited state and its couplings to the continuum have also been taken into consideration. It is found that the inelastic excitation/breakup of 17 F affect the fusion cross sections very nominally even for a heavy target like Pb. On the other hand, calculations for fusion of the one-proton halo nucleus 8 B on a Pb target show a significant suppression of the complete fusion cross section above the Coulomb barrier. This is due to the larger breakup probability of 8 B as compared to that of 17 F . However, even for 8 B , there is little change in the complete fusion cross sections as compared to the no-coupling case at sub-barrier energies.

scholarly journals INCLUSIVE PRODUCTION OF INTERMEDIATE MASS FRAGMENTS IN 20Ne+Ag,Au INTERACTIONS AT 20-60 MeV/nucleon

2020 ◽  
Vol 2 ◽  
pp. 42
Author(s):  
N. H. Papadakis ◽  
Et al.
Keyword(s):  
Cross Sections ◽  
Incident Energy ◽  
Energy Spectra ◽  
Source Analysis ◽  
Angular Distributions ◽  
Intermediate Mass ◽  
Gold Target ◽  
Moving Sources ◽  
Distinctive Role

Energy spectra and angular distributions of intermediate mass fragments were measured at 20, 30, 40, 50 and 60 MeV/nucleon incident energies. Assuming two prevailing origins, fragmentation and evaporation (or fission), the measured energy spectra and angular distributions are reproduced by emission from two moving sources. The dependence of the parameters extracted for the sources on the fragment charge and on the incident energy is discussed. The distinctive role of fission in the case of the gold target is stressed. Xuclear fragmentation cross sections deduced from the moving source analysis are given and discussed for the two systems.

scholarly journals Rosetta Mission: Electron Scattering Cross Sections - Data Needs and Coverage in BEAMDB Database

2017 ◽  
Author(s):  
Bratislav P. Marinković ◽  
Jan Hendrik Bredehöft ◽  
Veljko Vujčić ◽  
Darko Jevremović ◽  
Nigel J. Mason
Keyword(s):  
Electron Impact ◽  
Electron Scattering ◽  
Cross Sections ◽  
Molecular Data ◽  
Scattering Data ◽  
Particle Analysis ◽  
Detailed Knowledge ◽  
Molecular Systems ◽  
Rosetta Mission

The emission of [O I] lines in the coma of Comet 67P/Churyumov-Gerasimenko during the Rosetta mission have been explained by electron impact dissociation of water rather than the process of photodissociation. This is the direct evidence for the role of electron induced processing has been seen on such a body. Analysis of other emission features is handicapped by a lack of detailed knowledge of electron impact cross sections which highlights the need for a broad range of electron scattering data from the molecular systems detected on the comet. In this paper we present an overview of the needs for electron scattering data relevant for the understanding of observations in coma, the tenuous atmosphere and on the surface of 67P/Churyumov-Gerasimenko during the Rosetta mission. The relevant observations for elucidating the role of electrons come from optical spectra, particle analysis using the ion and electron sensors and mass spectrometry measurements. To model these processes electron impact data should be collated and reviewed in an electron scattering database and an example is given in the BEAMD, which is a part of a larger consortium of Virtual Atomic and Molecular Data Centre &ndash; VAMDC.

Confronting electron and neutrino–nucleus interactions: Can the axial mass anomaly be resolved?

2014 ◽  
Vol 23 (04) ◽  
pp. 1430005 ◽  
Author(s):  
Omar Benhar
Keyword(s):  
Cross Sections ◽  
Target Nucleus ◽  
Reaction Mechanisms ◽  
Short Review ◽  
Scattering Data ◽  
Final States ◽  
Neutrino Interactions ◽  
Axial Mass ◽  
Nucleus Scattering

Comparison between electron– and neutrino–nucleus scattering data suggests that the so-called axial mass anomaly — i.e., the large disagreement between the value of the nucleon axial mass extracted from the analysis of neutrino interactions with carbon and oxygen and that obtained from deuteron data — is a manifestation of the difficulties in the interpretation of the flux averaged neutrino cross-sections. In this short review, I discuss the role of reaction mechanisms leading to the excitation of two particle–two hole final states of the target nucleus, which are believed to be responsible for the observed excess of quasielastic events, and argue that taking into account their effect may help to reconcile the sizeably different values of the axial mass reported by the MiniBooNe and NOMAD Collaborations.

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