Neutrons from Fission

Highlights from more than 60 years of research on neutron emission in fission reactions are surveyed. The emphasis is put on low energy fission. First, global average multiplicities, multiplicity distributions and neutron spectra are discussed. Next, angular distributions of neutrons relative to the fission axis are shown to point to the existence of neutrons emitted right at scission. Then the dependence of neutron emission on the masses and kinetic energies of fragments are considered, including correlations between neutrons emitted from complementary fragments. Finally heavy ion induced fission of compound nuclei with masses up to the region of superheavy nuclei is reviewed. Throughout the role neutron research has played in contributing to our understanding of fission is stressed.