scholarly journals CROSS-SECTIONS IN PHOTONUCLEAR REACTIONS WITH MULTIPLE NEUTRON EMISSION

2019 ◽  
pp. 144-148
Author(s):  
O.A. Bezshyyko ◽  
O.M. Vodin ◽  
L.O. Golinka-Bezshyyko ◽  
A.V. Kotenko ◽  
V.A. Kushnir ◽  
...  
Keyword(s):  
Energy Dependence ◽  
Cross Sections ◽  
Neutron Emission ◽  
Reaction Cross ◽  
Photonuclear Reactions ◽  
Level Densities ◽  
Relative Contribution ◽  
Dipole Resonance ◽  
Talys 1.8 Code ◽  
Reaction Cross Sections

The energy dependence of the reaction cross-sections A(γ,xn)(A-xn) was studied in the energy range 19...70 MeV, i.e. beyond Great Dipole Resonance (GDR) region. Experimental data were taken from international database EXFOR for range of nuclear mases (55 < A < 209). Theoretical values of cross sections were obtained using TALYS-1.8 code. Several models of level densities with both enabled and disabled pre-equilibrium mechanism were considered in our simulations. Obtained results let us to make conclusions about different mechanisms of photonuclear reactions on certain nuclei, energy dependence of their relative contribution.

scholarly journals ISOMER RATIOS IN PHOTONUCLEAR REACTIONS WITH MULTIPLE NEUTRON EMISSION

2019 ◽  
pp. 38-46
Author(s):  
O.M. Vodin ◽  
O.A. Bezshyyko ◽  
L.O. Golinka-Bezshyyko ◽  
I.M. Kadenko ◽  
V.A. Kushnir ◽  
...  
Keyword(s):  
Energy Dependence ◽  
Neutron Emission ◽  
Photonuclear Reactions ◽  
International Database ◽  
Level Densities ◽  
Relative Contribution ◽  
Dipole Resonance ◽  
Wide Range ◽  
Talys 1.8 Code ◽  
Isomeric Ratios

The aim of this work is studying of gamma-quanta energy dependence of isomeric ratios in A(γ,xn)m,g(A − xn) reactions in energy range 35...100MeV , i.e. beyond Great Dipole Resonance (GDR) region. Experimental data were taken from international database EXFOR for a wide range of nuclear mases (55 < A < 181). Theoretical values of isomeric ratios were obtained using TALYS-1.8 code. Several models of level densities with both enabled and disabled pre-equilibrium mechanism were considered in our simulations. Obtained results let us to make conclusions about different mechanisms of photonuclear reactions on certain nuclei, energy dependence of their relative contribution.

Microscopic analysis of the energy dependence of the 6He, 6Li + 28Si total reaction cross sections in the energy range E = 5−50 A MeV

2008 ◽  
Vol 72 (3) ◽  
pp. 356-360
Author(s):  
K. V. Lukyanov ◽  
E. V. Zemlyanaya ◽  
V. K. Lukyanov ◽  
I. N. Kukhtina ◽  
Yu. E. Penionzhkevich ◽  
...  
Keyword(s):  
Energy Range ◽  
Energy Dependence ◽  
Cross Sections ◽  
Microscopic Analysis ◽  
Reaction Cross ◽  
Total Reaction ◽  
Reaction Cross Sections

scholarly journals Microscopie Calculations of Nuclear Level Densities and Astrophysical Applications

2019 ◽  
Vol 11 ◽  
Author(s):  
P. Demetriou ◽  
S. Goriely
Keyword(s):  
Cross Sections ◽  
Level Density ◽  
Reaction Cross ◽  
Neutron Resonance ◽  
Thermodynamic Quantities ◽  
Microscopic Approach ◽  
Level Densities ◽  
Hartree Fock ◽  
The Impact ◽  
Reaction Cross Sections

A new level density formula based on a microscopic calculation of the thermodynamic quantities using the deformed Hartree-Fock-BCS method is proposed. In the microscopic approach shell, pairing and deformation effects on the thermodynamic quantities are treated consistently. The final level density formula is shown to be in close agreement with experimental neutron resonance spacings and low energy states. The impact of the newly-determined level densities on nuclear reaction cross sections and rates of relevance in astrophysics applications is presented.

Energy dependence of (p,t)-reaction cross-sections

1974 ◽  
Vol 11 (4) ◽  
pp. 293-297 ◽  
Author(s):  
H. Toki ◽  
M. Sano ◽  
H. Orihara ◽  
Y. Ishizaki
Keyword(s):  
Energy Dependence ◽  
Cross Sections ◽  
Reaction Cross ◽  
Reaction Cross Sections

scholarly journals Study of the photon strength functions and level density in the gamma decay of the n + 234U reaction

2019 ◽  
Vol 211 ◽  
pp. 02002 ◽  
Author(s):  
J. Moreno-Soto ◽  
E Berthoumieux ◽  
E Dupont ◽  
F Gunsing ◽  
O Serot ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Cross Sections ◽  
High Efficiency ◽  
Level Density ◽  
Reaction Cross ◽  
Level Densities ◽  
Strength Functions ◽  
Gamma Decay ◽  
Reaction Cross Sections ◽  
Nuclear Applications

The accurate calculations of neutron-induced reaction cross sections are relevant for many nuclear applications. The photon strength functions and nuclear level densities are essential inputs for such calculations. These quantities for 235U are studied using the measurement of the gamma de-excitation cascades in radiative capture on 234U with the Total Absorption Calorimeter at n_TOF at CERN. This segmented 4π gamma calorimeter is designed to detect gamma rays emitted from the nucleus with high efficiency. This experiment provides information on gamma multiplicity and gamma spectra that can be compared with numerical simulations. The code DICEBOXC is used to simulate the gamma cascades while GEANT4 is used for the simulation of the interaction of these gammas with the TAC materials. Available models and their parameters are being tested using the present data. Some preliminary results of this ongoing study are presented and discussed.

scholarly journals Statistical Hauser-Feshbach Model Description of (n,α) Reaction Cross Sections for the Weak s-Process

Universe ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 25
Author(s):  
Sema Küçüksucu ◽  
Mustafa Yiğit ◽  
Nils Paar
Keyword(s):  
Cross Sections ◽  
Density Functional ◽  
Experimental Studies ◽  
Reaction Cross ◽  
Model Description ◽  
Energy Density Functional ◽  
Model Calculations ◽  
Level Densities ◽  
Environment Model ◽  
Reaction Cross Sections

The (n,α) reaction contributes in many processes of energy generation and nucleosynthesis in stellar environment. Since experimental data are available for a limited number of nuclei and in restricted energy ranges, at present only theoretical studies can provide predictions for all astrophysically relevant (n,α) reaction cross sections. The purpose of this work is to study (n,α) reaction cross sections for a set of nuclei contributing in the weak s-process nucleosynthesis. Theory framework is based on the statistical Hauser-Feshbach model implemented in TALYS code with nuclear masses and level densities based on Skyrme energy density functional. In addition to the analysis of the properties of calculated (n,α) cross sections, the Maxwellian averaged cross sections are described and analyzed for the range of temperatures in stellar environment. Model calculations determined astrophysically relevant energy windows in which (n,α) reactions occur in stars. In order to reduce the uncertainties in modeling (n,α) reaction cross sections for the s-process, novel experimental studies are called for. Presented results on the effective energy windows for (n,α) reaction in weak s-process provide a guidance for the priority energy ranges in the future experimental studies.

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