Speaker
Description
Nuclear fission is a very intricate and complex process that, despite being discovered more than 85 years ago, still lacks a full complete description. In fact, the question about the distribution of the deformation and excitation energy of the fissioning nucleus between the newly-born primary fission fragments right after scission is still discussed. The consensus states that around 80% of the energy released by fission converts into kinetic energy of the primary fission fragments while the remaining 20% are distributed between the primary fragments in terms of excitation energy. This distribution hasn’t been properly measured up to now. The angular momentum of the primary fission fragments before any neutron emission hasn’t been measured before either. In order to answer this question, one needs to probe the structure of these high excitation energy nuclei through the measurement and reconstruction of their prompt deexcitation channels, in other words: the prompt neutron and prompt gamma emission.
Performing these measurements and characterizing both the neutron and gamma prompt emissions and the competition between the two during the deexcitation of the primary fission fragments, fragment by fragment, is the core of my work. The experimental set up of my PhD experiment allows the measurement of both neutrons and gamma rays along with fragment selection and kinetics reconstruction thanks to a twin Frisch-Grid ionization chamber.
The capability to measure neutrons and gamma emissions concurrently, combined with the ability to select the decaying fragments, provides a complete insight on the primary fragment’s structure. Further more, assessing the correlation between the prompt neutron and prompt gamma emissions will either confirm or refute the rather fragile consensus where when at high excitation energy: neutrons first and gammas after.
This line of research is crucial for advancing our understanding of nuclear fission, which has numerous applications and implications across various scientific fields, including nuclear energy, reactor physics and fundamental nuclear physics. This work holds promise in shedding light on the elusive aspects of fission and contributing to the development of a more complete understanding of this fundamental nuclear process.
