The Laboratory of physics studies at CEA/IRESNE Cadarache has been developing for about ten years a Monte-Carlo code called FIFRELIN capable of simulating the nuclei (fragments) resulting from a fission reaction and predicting their de-excitation by neutron, gamma and electron emission. Thanks to this tool, the calculation of a large number of 'fission observables' needed in reactor physics becomes possible. However, it is necessary to validate the models implemented in the code. One way of doing this is to carry out so-called multi-observable experiments that FIFRELIN will try to reproduce by refining the models and/or the parameters of these models. These multi-observable experiments consist in measuring in coincidence the two fission fragments as well as the neutrons and prompt gamma emitted by these fragments, in order to determine the correlations between these observables. This is precisely the purpose of the VESPA++ device, recently developed by the Joint Research Center of the European Commission located in Geel, Belgium (JRC-Geel).
Two 18-month phases are planned during this thesis. A first experimental phase during which the student will be based at JRC-Geel. He/She will get familiar with the functioning of the VESPA++ device, will participate in the experiments and analyze the raw data collected. A second phase will be dedicated to the improvement of the models implemented in FIFRELIN in order to reproduce the experimental results. During this second phase, the student will be based at Cadarache.