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Theses
Etude préliminaire de la mesure du rapport alpha, rapport de la section efficace moyenne de capture sur celle de fission de l'233U, sur la plateforme PEREN - Développement et étude du dispositif expérimental -
Etude préliminaire de la mesure du rapport alpha, rapport de la section efficace moyenne de capture sur celle de fission de l'233U, sur la plateforme PEREN - Développement et étude du dispositif expérimental -
Abstract : This Ph-D thesis was intended to prepare a precise measurement of the alpha ratio of 233U between 1eV and 10keV. This ratio is a key-parameter to calculate the breeding ratio of reactors based on the 232Th/233U cycle. This measurement would be performed, at the LPSC, on the experimental platform PEREN which is composed of a lead slowing-down time spectrometer associated with an intense pulsed neutron generator. Capture and fission rates are measured thanks to 8 scintillators YAP used in coincidence and surrounding a fission chamber. Preliminary tests using 235U resulted in a very low signal to background ratio despite the successive improvements. The different components of the background were identified and quantified experimentally and thanks to simulation tools (MCNP and GEANT4). Nevertheless, the signal to background ratio has still to be increased by about a factor 10 at least, to allow the measurement of the capture of a fissile element with such an experimental setup.
Cited literature [94 references]
https://tel.archives-ouvertes.fr/tel-00269052
Contributor : Marie-Anne Cognet <>
Submitted on : Monday, April 7, 2008 - 1:25:49 PM
Last modification on : Thursday, November 19, 2020 - 12:58:48 PM
Long-term archiving on: : Tuesday, September 21, 2010 - 4:06:22 PM
Contributor : Marie-Anne Cognet <>
Submitted on : Monday, April 7, 2008 - 1:25:49 PM
Last modification on : Thursday, November 19, 2020 - 12:58:48 PM
Long-term archiving on: : Tuesday, September 21, 2010 - 4:06:22 PM