ABSTRACT
The emission of charged particles from the ground or excited states of nuclei is a transformation that is governed by several physical processes. A dominant one is the energy release associated with the difference in mass between the initial nucleus and the sum of the masses of the final products of the decay process. Other factors affect the details of charged-particle emission, e.g., spin, isospin, nuclear shell structure, the Coulomb barrier, and nuclear shape-related effects. It is, however, the energetics of the process that determine whether it will occur and whether one or more final states will be involved. In radioactive decay, charged-particle emission occurs from nuclear ground state, as in fission, and alpha, heavy ion, or proton radioactivity. Charged-particle emission may also occur from excited nuclear states, as in beta-delayed particle emission from states formed in a radioactive decay process, from fission isomers, or as charged-particle evaporation from excited nuclei produced in a nuclear reaction. When these transformations occur among well-characterized nuclei (those that lie near the line of beta stability) the energetics of the process are frequently well determined because the masses of the nuclide involved have generally been previously measured.
