3. Spectra and multiplicities of prompt particles

This section deals with models that are useful for assessing the characteristics (spectra and multiplicities) of the two prompt particles emitted during fission, namely neutrons and gammas (there may also be emission of so-called conversion electrons (see § 3.2 ), which we won't go into here). These neutrons and gammas play an essential role in fundamental physics (their characteristics help us to better understand the fission process), but also in numerous neutronics applications (calculation of core reactivity, calculation of neutron fluence on a reactor vessel impacting on its lifetime, estimation of reactor heating...