5. Fission

The fission of a "heavy" atomic nucleus (i.e. with a high mass number A) caused by interaction with a neutron was discovered in 1938 by Hahn and Strassman on the one hand, and Joliot and Frisch on the other. It consists in the fragmentation of the compound nucleus, most often into two entities, more rarely into three (ternary fission), accompanied by neutron and gamma emission. The resulting entities are called -fission products (FP) and are generally radioactive nuclei that decay through β transitions and/or electron capture (β ^– , β ⁺ , CE, neutron emission...) to reach the valley of stability. These radioactive transitions are themselves accompanied by gamma and neutrino or antineutrino emission.

The first theoretical interpretation of fission was given by Bohr and Wheeler...