Gamma rays from fission fragments

Abstract

High-resolution measurements on gamma -rays from fission fragments have given a wealth of information on the structure of neutron-rich nuclei and on the mechanism of the fission process. Experiments to study prompt gamma -rays which deexcite secondary fragments have been greatly facilitated by the introduction of large arrays of Compton suppressed gamma -ray detectors. These have been used recently to give important data on new neutron-rich nuclei with up to ten more neutrons than the nearest stable isotope. High-resolution experiments have also been performed to study gamma -rays which follow the beta - decays of the ground states of secondary fragments, and extensive data now exist on decay properties of nuclei with up to twelve more neutrons than the nearest stable isotope. This paper reviews the scope of measurements which can be made on fission gamma -rays and the techniques used in the experiments. It also discusses some results recently obtained on nuclear structure of fragments and on beta - decays, and reviews information on fragment spins and other data relevant to fission dynamics.