General information
Organisation
The French Alternative Energies and Atomic Energy Commission (CEA) is a key player in research, development and innovation in four main areas :
• defence and security,
• nuclear energy (fission and fusion),
• technological research for industry,
• fundamental research in the physical sciences and life sciences.
Drawing on its widely acknowledged expertise, and thanks to its 16000 technicians, engineers, researchers and staff, the CEA actively participates in collaborative projects with a large number of academic and industrial partners.
The CEA is established in ten centers spread throughout France
Reference
SL-DES-25-0182
Thesis topic details
Category
Corpuscular physics and outer space
Thesis topics
Modeling of nuclear charge polarization as part of fission yield evaluation: applications to actinides of interest to the nuclear fuel cycle
Contract
Thèse
Job description
Nuclear data is crucial for civil nuclear energy applications, being the bridge between the micoscopic properties of nuclei and the “macroscopic good values” needed for cycle and reactor physics studies. The laboratory of physics studies at CEA/IRESNE Cadarache is involved in the evaluation of these nuclear physics observables, in the framework of the JEFF Group and the Coordinated Research Project (CRP) of IAEA. The recent development of a new methodology for thermal neutrons induced fission product yield evaluation (fission product yields after prompt neutron emission) has improved the accuracy of the evaluations proposed for the JEFF-4.0 Library, together with their covariance matrix. To extend the assessments of fission yields induced by thermal neutrons to the fast neutron spectrum, it is necessary to develop a coupling of current evaluation tools with fission fragment yield models (before prompt neutron emission). This coupling is essential to extrapolate the actual studies on thermal fission of 235U and 239Pu to less experimentally known nuclei (241Pu, 241Am, 245Cm) or to study the incident neutron energy dependence of fission yields. One of the essential missing components is the description of the nuclear charge distribution (Z) as a function of the mass of the fission fragments and the incident neutron energy. These distributions are characterized by a key parameter: the charge polarization. This polarization reflects an excess (respectively deficiency) of proton in light (respectively heavy) fission fragments compared to the average charge density of the fissioning nucleus. If this quantity has been measured for the 235U(nth,f) reaction, it is incomplete for other neutron energies or other fissioning systems. The perspectives of this subject concern as much the impact of these new evaluations on the key quantities for electronuclear applications as well as the validation of the fission mechanisms described by microscopic fission models.
University / doctoral school
Ecole Doctorale de Physique de Grenoble (EdPHYS)
Université Grenoble Alpes
Thesis topic location
Site
Cadarache
Requester
Position start date
01/11/2025
Person to be contacted by the applicant
KESSEDJIAN Gregoire
gregoire.kessedjian@cea.fr
CEA
DES/IRESNE/DER/SPRC/LEPh
DES/IRESNE/DER/SPRC/LEPh
CEA-Cadarache, Batiment 230, 13108 Saint Paul lez Durance
0442254114
Tutor / Responsible thesis director
Kessedjian Grégoire
gregoire.kessedjian@cea.fr
CEA
DES/IRESNE/DER/SPRC/LEPh
DES/IRESNE/DER/SPRC/LEPh
CEA-Cadarache, Batiment 230, 13108 Saint Paul lez Durance
0442254114
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