Nuclear-reaction times from Bremsstrahlung cross-sections: A wave packet description

1976 ◽  
Vol 16 (9) ◽  
pp. 257-260 ◽  
Author(s):  
I. Massa ◽  
A. Uguzzoni ◽  
G. Vannini
Keyword(s):  
Wave Packet ◽  
Nuclear Reaction ◽  
Cross Sections ◽  
Reaction Times

scholarly journals The feasibility of measuring the nuclear reaction cross sections at energies of several KeV in a target under laser compression

1987 ◽  
Vol 5 (2) ◽  
pp. 399-404 ◽  
Author(s):  
V. I. Kukulin ◽  
V. M. Krasnopol'sky ◽  
V. T. Voronchev
Keyword(s):  
Nuclear Reaction ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Velocity Distribution Function ◽  
Reaction Cross ◽  
Straightforward Method ◽  
Energy Behaviour ◽  
Low Energies ◽  
Ion Velocity Distribution Function ◽  
Reaction Cross Sections

The work proposes a straightforward method for determining the nuclear reaction cross sections at extremely low energies (E ≃ 1–100 keV) on the basis of the measurements of the relative yield of fast particles which are products of the nuclear reactions in a target under laser compression. On the other hand, the proposed method makes it possible to find the averaged form of the ion velocity distribution function if the low-energy behaviour of the respective cross sections is known.

ABUNDANCE ANOMALIES PRODUCED BY NUCLEAR REACTIONS IN STELLAR SURFACE LAYERS: I. NUCLEAR-REACTION RATES

1967 ◽  
Vol 45 (10) ◽  
pp. 3275-3296 ◽  
Author(s):  
P. J. Brancazio ◽  
A. Gilbert ◽  
A. G. W. Cameron
Keyword(s):  
Statistical Theory ◽  
Nuclear Reaction ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Level Density ◽  
Preliminary Investigation ◽  
Computer Time ◽  
Reaction Rates ◽  
Reaction Cross ◽  
Surface Layers

A preliminary investigation of the effects on abundances in stellar surfaces of extensive nuclear bombardment required the calculation of more than 105 nuclear-reaction cross sections. It was necessary to develop simplified methods for using the statistical theory of nuclear reactions to make these calculations in order that the computer time should not be prohibitive. These methods are described here and the results are compared with experiment. The accuracy of the calculations is, in general, about as good as, or somewhat better than, that obtained in previous applications of the statistical theory, probably because the use of an accurate level density formula outweighed the crudity of other approximations.

scholarly journals Global predictions for astrophysics applications

2020 ◽  
Vol 13 ◽  
pp. 18
Author(s):  
P. Demetriou
Keyword(s):  
Nuclear Reaction ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Nuclear Astrophysics ◽  
Reaction Network ◽  
Reaction Rates ◽  
Reaction Cross ◽  
Hartree Fock ◽  
Microscopic Models ◽  
The Stability

Nuclear reaction rates play a crucial role in nuclear astrophysics. In the last decades there has been an enormous effort to measure reaction cross sections and extensive experimental databases have been compiled as a result. In spite of these efforts, most nuclear reaction network calculations still have to rely on theoretical predic- tions of experimentally unknown rates. In particular, in astrophysics applications such as the s-, r- and p-process nucleosynthesis involving a large number of nuclei and nuclear reactions (thousands). Moreover, most of the ingredients of the cal- culations of reaction rates have to be extrapolated to energy and/or mass regions that cannot be explored experimentally. For this reason it is important to develop global microscopic or semi-microscopic models of nuclear properties that give an accurate description of existing data and are reliable for predictions far away from the stability line. The need for more microscopic input parameters has led to new devel- opments within the Hartree-Fock-Bogoliubov method, some of which are presented in this paper.

Nuclear Reaction Times in the Deep-Inelastic U + U Collision Deduced fromK-Shell Ionization Probabilities

1984 ◽  
Vol 53 (14) ◽  
pp. 1329-1332 ◽  
Author(s):  
Ch. Stoller ◽  
M. Nessi ◽  
E. Morenzoni ◽  
W. Wölfli ◽  
W. E. Meyerhof ◽  
...  
Keyword(s):  
Nuclear Reaction ◽  
Reaction Times ◽  
Shell Ionization

Theoretical investigations of the Au++H2 reactive scattering by the time-dependent quantum wave packet method

2017 ◽  
Vol 31 (06) ◽  
pp. 1750039 ◽  
Author(s):  
Wentao Lee ◽  
Haixiang He ◽  
Maodu Chen
Keyword(s):  
Wave Packet ◽  
Cross Sections ◽  
Collision Energy ◽  
Time Dependent ◽  
Reactive Scattering ◽  
Total Reaction ◽  
Theoretical Investigations ◽  
Classical Trajectories ◽  
Quantum Wave

Employing the state-to-state time-dependent quantum wave packet method, the Au[Formula: see text]H2 reactive scattering with initial states [Formula: see text], [Formula: see text] and 1 were investigated. Total reaction probabilities, product state-resolved integral cross-sections (ICSs) and differential cross-sections (DCSs) were calculated up to collision energy of 4.5 eV. The numerical results show that total reaction probabilities and ICSs increase with increasing collision energies, and there is little effect to the reactive scattering processes from the rotational excitation of H2 molecule. Below collision energy of around 3.0 eV, the role of the potential well in the entrance channel is significant and the reactive scattering proceeds dominantly by an indirect process, which leads to a nearly symmetric shape of the DCSs. With collision energy higher than 4.0 eV, the reactive scattering proceeds through a direct process, which leads to a forward biased DCSs, and also a hotter rotational distributions of the products. Total ICS agrees with the results by the quasi-classical trajectories theory very well, which suggests that the quantum effects in this reactive process are not obvious. However, the agreement between the experimental total cross-section and our theoretical result is not so good. This may be due to the uncertainty of the experiment or/and the inaccuracy of the potential energy surface.

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