Cold fission as emission of fragments

Cold fission, defined as a process where virtually all the available energy goes into the total kinetic energies of the fragments, is considered to be identical to spontaneous decay with emission of fragments such as 14 C, 24 Ne, 28 Mg and 32 Si, already observed experimentally (exotic decays). Both processes lead to fragments in their ground states. It is shown that the criterion of maximum barrier penetrability around the charge equilibrated values in cold fission could explain the recent experiments on the cold fission of thermal-neutron induced fission of U and Pu isotopes and of the spontaneous fission of 252 Cf with fragment masses and charges being resolved one-by-one. It is also shown that, contrary to exotic decays where the deformations of the emitted fragments are not very important, the deformations of both fragments are essential for the explanation of the present data. The deduced quadrupole deformations are in total agreement with the experimental deformation values and in partial agreement with the theoretical ones based on macroscopic-microscopic models. The authors conclude that cold fragmentation of heavy nuclei with fragments in their ground states is a quite general phenomenon.