Study of 235U(n,f) reaction with FALSTAFF spectrometer in a NFS facility

The neutron-induced fission cross-section of actinides is a critical parameter in nuclear physics, playing a significant role in both fundamental research and applied nuclear science. This process is essential for the advancement of nuclear reactor technologies and the enhancement of our understanding of nuclear reactions. Despite extensive research over the decades, there is still a need for additional data to refine models and improve nuclear data evaluations. This study investigates the correlation between fragment mean kinetic energies and masses across different incident neutron energies, aiming to deepen our comprehension of the fission process.

An experiment was conducted in the time-of-flight (TOF) area of the Neutrons For Science (NFS) facility at SPIRAL2/GANIL, utilizing a one-arm configuration of the FALSTAFF spectrometer to investigate the neutron-induced fission of 235U. The NFS facility provides high-energy neutron beams ranging from 1 MeV to 40 MeV. The FALSTAFF spectrometer comprises LaBr3(Ce) detectors for precise time referencing, a Secondary Electron Detector (SED) for time-of-flight and fragment position determination, and an axial ionization chamber for profiling the kinetic energy and energy loss of the fission fragments.

The results obtained from these measurements will be discussed in detail during the presentation.