Abstract
The calculation of the anti-trap factor of a lattice is complex when a large fraction of captures occurs in a range of energies where the spectrum in the fuel is considerably different from the simple dE/E law. This is particularly true for heavy water lattices in which the distances. between the bars are generally fairly large with respect to the slowing-down length. In order to take into account this effect it is necessary both to know the constitution of the effective resonance integral as a function of the energy, and to be able to calculate the distribution in the fuel. This report is devoted to these two problems. An improved method of treating the statistical domain makes it possible to plot the curves of the cross-sections per unit lethargy for various shapes of the fuel. Furthermore, the slowing-down of the neutrons is studied using a Monte-Carlo method which makes it possible in particular to take into account the perturbations caused by the non-moderating rods. A study is also made of the problem of shielding effects due to the captures themselves. (authors) [French] Le calcul du facteur antitrappe dans un reseau est complique lorsqu'une fraction importante des captures a lieu dans
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Naudet, R;
Mougey, J
[1]
- Commissariat a l'Energie Atomique, Saclay (France). Centre d'Etudes Nucleaires
Citation Formats
Naudet, R, and Mougey, J.
Calculation of the anti-trap factor in heavy water lattices; Calcul du facteur antitrappe dans les reseaux a eau lourde.
France: N. p.,
1965.
Web.
Naudet, R, & Mougey, J.
Calculation of the anti-trap factor in heavy water lattices; Calcul du facteur antitrappe dans les reseaux a eau lourde.
France.
Naudet, R, and Mougey, J.
1965.
"Calculation of the anti-trap factor in heavy water lattices; Calcul du facteur antitrappe dans les reseaux a eau lourde."
France.
@misc{etde_20771724,
title = {Calculation of the anti-trap factor in heavy water lattices; Calcul du facteur antitrappe dans les reseaux a eau lourde}
author = {Naudet, R, and Mougey, J}
abstractNote = {The calculation of the anti-trap factor of a lattice is complex when a large fraction of captures occurs in a range of energies where the spectrum in the fuel is considerably different from the simple dE/E law. This is particularly true for heavy water lattices in which the distances. between the bars are generally fairly large with respect to the slowing-down length. In order to take into account this effect it is necessary both to know the constitution of the effective resonance integral as a function of the energy, and to be able to calculate the distribution in the fuel. This report is devoted to these two problems. An improved method of treating the statistical domain makes it possible to plot the curves of the cross-sections per unit lethargy for various shapes of the fuel. Furthermore, the slowing-down of the neutrons is studied using a Monte-Carlo method which makes it possible in particular to take into account the perturbations caused by the non-moderating rods. A study is also made of the problem of shielding effects due to the captures themselves. (authors) [French] Le calcul du facteur antitrappe dans un reseau est complique lorsqu'une fraction importante des captures a lieu dans un domaine d'energie ou le spectre dans le combustible s'ecarte sensiblement de la loi simple en dE/E. Ceci est particulierement vrai pour les reseaux a eau lourde dans lesquels les distances entre barres sont en general assez grandes vis-a-vis de la longueur de ralentissement. Pour tenir compte de cet effet il faut connaitre d'une part la decomposition de l'integrale de resonance effective en fonction de l'energie, d'autre part savoir calculer le spectre dans le combustible. Le rapport est consacre a ces deux problemes. Un traitement ameliore du domaine statistique permet de tracer des courbes de sections de capture par unite de lethargie pour differentes geometries de barreaux. D'autre part le ralentissement des neutrons est etudie par une methode de Monte Carlo, qui permet en particulier de tenir compte de la perturbation apportee par les barreaux non ralentisseurs. On etudie egalement le probleme des effets d'ombre des captures les unes sur les autres. (auteurs)}
place = {France}
year = {1965}
month = {Jul}
}
title = {Calculation of the anti-trap factor in heavy water lattices; Calcul du facteur antitrappe dans les reseaux a eau lourde}
author = {Naudet, R, and Mougey, J}
abstractNote = {The calculation of the anti-trap factor of a lattice is complex when a large fraction of captures occurs in a range of energies where the spectrum in the fuel is considerably different from the simple dE/E law. This is particularly true for heavy water lattices in which the distances. between the bars are generally fairly large with respect to the slowing-down length. In order to take into account this effect it is necessary both to know the constitution of the effective resonance integral as a function of the energy, and to be able to calculate the distribution in the fuel. This report is devoted to these two problems. An improved method of treating the statistical domain makes it possible to plot the curves of the cross-sections per unit lethargy for various shapes of the fuel. Furthermore, the slowing-down of the neutrons is studied using a Monte-Carlo method which makes it possible in particular to take into account the perturbations caused by the non-moderating rods. A study is also made of the problem of shielding effects due to the captures themselves. (authors) [French] Le calcul du facteur antitrappe dans un reseau est complique lorsqu'une fraction importante des captures a lieu dans un domaine d'energie ou le spectre dans le combustible s'ecarte sensiblement de la loi simple en dE/E. Ceci est particulierement vrai pour les reseaux a eau lourde dans lesquels les distances entre barres sont en general assez grandes vis-a-vis de la longueur de ralentissement. Pour tenir compte de cet effet il faut connaitre d'une part la decomposition de l'integrale de resonance effective en fonction de l'energie, d'autre part savoir calculer le spectre dans le combustible. Le rapport est consacre a ces deux problemes. Un traitement ameliore du domaine statistique permet de tracer des courbes de sections de capture par unite de lethargie pour differentes geometries de barreaux. D'autre part le ralentissement des neutrons est etudie par une methode de Monte Carlo, qui permet en particulier de tenir compte de la perturbation apportee par les barreaux non ralentisseurs. On etudie egalement le probleme des effets d'ombre des captures les unes sur les autres. (auteurs)}
place = {France}
year = {1965}
month = {Jul}
}