scholarly journals Three-dimensional time-dependent Hartree-Fock calculations ofO16+O16andCa40+Ca40fusion cross sections

1978 ◽  
Vol 17 (5) ◽  
pp. 1700-1705 ◽  
Author(s):  
P. Bonche ◽  
B. Grammaticos ◽  
S. Koonin
Keyword(s):  
Cross Sections ◽  
Three Dimensional ◽  
Time Dependent ◽  
Hartree Fock

scholarly journals Josephson oscillations in split one-dimensional Bose gases

2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Yuri Daniel van Nieuwkerk ◽  
Jörg Schmiedmayer ◽  
Fabian Essler
Keyword(s):  
Three Dimensional ◽  
Time Dependent ◽  
Dimensional Theory ◽  
Bose Gases ◽  
Microscopic Description ◽  
One Dimensional ◽  
Hartree Fock ◽  
Equilibrium Dynamics ◽  
Self Consistent ◽  
Double Well Potential

We consider the non-equilibrium dynamics of a weakly interacting Bose gas tightly confined to a highly elongated double well potential. We use a self-consistent time-dependent Hartree--Fock approximation in combination with a projection of the full three-dimensional theory to several coupled one-dimensional channels. This allows us to model the time-dependent splitting and phase imprinting of a gas initially confined to a single quasi one-dimensional potential well and obtain a microscopic description of the ensuing damped Josephson oscillations.

Comparisons of two- and three-dimensional time-dependent Hartree-Fock calculations of the reactionsO16+O16andCa40+Ca40

1978 ◽  
Vol 18 (6) ◽  
pp. 2631-2640 ◽  
Author(s):  
K. T. R. Davies ◽  
H. T. Feldmeier ◽  
H. Flocard ◽  
M. S. Weiss
Keyword(s):  
Three Dimensional ◽  
Time Dependent ◽  
Hartree Fock

scholarly journals NEUTRON NOISE PATTERNS FROM COUPLED FUEL-ASSEMBLY VIBRATIONS

2021 ◽  
Vol 247 ◽  
pp. 02015
Author(s):  
M. Viebach ◽  
C. Lange ◽  
M. Seidl ◽  
Y. Bilodid ◽  
A. Hurtado
Keyword(s):  
Neutron Flux ◽  
Fuel Assembly ◽  
Cross Sections ◽  
Three Dimensional ◽  
Time Dependent ◽  
Radial Dependence ◽  
Feedback Parameter ◽  
Fuel Assemblies ◽  
Neutron Noise ◽  
The Impact

The neutron flux fluctuation magnitude of KWU-built PWRs shows a hitherto unexplained correlation with the types of loaded fuel assemblies. Also, certain measured long-range neutron flux fluctuation patterns in neighboring core quadrants still lack a closed understanding of their origin. The explanation of these phenomena has recently revived a new interest in neutron noise research. The contribution at hand investigates the idea that a synchronized coolant-driven vibration of major parts of the fuel-assembly ensemble leads to these phenomena. Starting with an assumed mode of such collective vibration, the resulting effects on the time-dependent neutron-flux distribution are analyzed via a DYN3D simulation. A three-dimensional representation of the time-dependent bow of all fuel assemblies is taken into account as a nodal DYN3D feedback parameter by time-dependent variations of the fuel-assembly pitch. The impact of its variation on the cross sections is quantified using a cross-section library that is generated from the output of corresponding CASMO5 calculations. The DYN3D simulation qualitatively reproduces the measured neutron-flux fluctuation patterns. The magnitude of the fluctuations and its radial dependence are comparable to the measured details. The results imply that collective fuel-assembly vibrations are a promising candidate for being the key to understand long-known fluctuation patterns in KWU built PWRs. Further research should elaborate on possible excitation mechanisms of the assumed vibration modes.

scholarly journals Newtonian dynamics of imaginary time-dependent mean field theory

2021 ◽  
Vol 252 ◽  
pp. 05001
Author(s):  
Aldo Bonasera
Keyword(s):  
Cross Sections ◽  
Classical Model ◽  
Mean Field Theory ◽  
Mean Field ◽  
Time Dependent ◽  
Fusion Reactions ◽  
Model Calculations ◽  
Hartree Fock ◽  
Direct Data ◽  
Path Integral Method

A Time Dependent Hartree-Fock (TDHF) based classical model is applied to sub-barrier fusion reactions using the Feynman Path Integral Method (FPIM). The fusion cross-sections and modified astrophysical S*-factors are calculated for the 12C+12C reactions and compared to direct and indirect experimental results. Different channels cross-sections are estimated from the statistical decay of the compound nucleus. A good agreement with the direct data is found. We suggest a complementary observable given by the (imaginary) action A easily derived from theory and experiments. When properly normalized by the action in the Gamow limit it has an upper value of 1 at zero beam energies. It becomes negative at the Coulomb barrier which is Vcb=5.05±0.05MeV from direct data and Vcb=5.5MeV from model calculations.

scholarly journals Three-dimensional time-dependent Hartree-Fock calculations: Application toO16+O16collisions

1978 ◽  
Vol 17 (5) ◽  
pp. 1682-1699 ◽  
Author(s):  
H. Flocard ◽  
S. E. Koonin ◽  
M. S. Weiss
Keyword(s):  
Three Dimensional ◽  
Time Dependent ◽  
Hartree Fock
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