Mesure des sections efficaces de diffusion élastique des neutrons sur le carbone et le fluor dans le domaine épithermique sur la plate-forme PEREN

Abstract : Molten Salt Reactor (MSR) based on Th/U cycle is one of the new generation concepts for nuclear energy production. A typical MSR is a graphite-moderated core with liquid fuel (^{7}LiF+ThF_{4}+UF_{4}). Many numerical studies based on Monte-Carlo codes are currently carried out but the validity of these numerical result relies on the precise knowledge of neutron cross sections used such as elastic scattering on carbon (\sigma_{C}), fluorine (\sigma_{F}) and lithium 7 (\sigma_{Li}).

The goal of this work is to obtain \sigma_{C} and \sigma_{F} between 1 eV and 100 keV. Such measurements have been performed at the Laboratoire de Physique Subatomique et de Cosmologie (LPSC) de Grenoble on the experimental platform PEREN using slowing-down time spectrometers (C and CF_{2}) associated to a pulsed neutron generator (GENEPI). Capture rates are obtained for reference materials (Au, Ag, Mo and In) using YAP scintillator coupled to a photo-multiplier.

Very precise simulations (MCNP code) of the experimental setup have been performed and comparison with experiments has led to the determination of \sigma_{C} and \sigma_{F} with accuracies of 1% and 2% respectively. These results show a small discrepancy to evaluated nuclear data file (ENDF).

Measures of total cross-sections \sigma_{C} and \sigma_{F} at higher energy (200-600\, keV) were also carried out at Centre des Etudes Nucléaires de Bordeaux using a transmission method. Mono-energetic neutrons were produced by protons accelerated by a Van de Graaff accelerator on a LiF target and transmitted neutrons are counted in a proportional hydrogen gaseous detector. Discrepancies of 5\% and 9\% for \sigma_{C} and \sigma_{F} respectively with ENDF have been shown.
Document type :
Theses
Nuclear Theory [nucl-th]. Université Joseph-Fourier - Grenoble I, 2005. French


https://tel.archives-ouvertes.fr/tel-00011285
Contributor : Nicolas Thiolliere <>
Submitted on : Tuesday, January 3, 2006 - 4:24:03 PM
Last modification on : Friday, January 6, 2006 - 9:03:35 PM

Identifiers

  • HAL Id : tel-00011285, version 1

Collections

LPSC | UJF | UGA

Citation

Nicolas Thiolliere. Mesure des sections efficaces de diffusion élastique des neutrons sur le carbone et le fluor dans le domaine épithermique sur la plate-forme PEREN. Nuclear Theory [nucl-th]. Université Joseph-Fourier - Grenoble I, 2005. French. <tel-00011285>

Export

Share

Metrics

Consultation de
la notice

240

Téléchargement du document

729