Cluster Aspects of 252Cf Spontaneous Fission

Abstract

An analysis of the spontaneous 252Cf fission into the Mo-Ba channel suggests the existence of two distinct modes of fission. The dominant one agrees with the general trend of fission fragment excitation energies. The second mode, occurring with a relative frequency of a few percent, is characterized by a total kinetic energy much lower than that of the first mode, with almost all of the difference appearing as excitation energy of the fragments. We argue that the second mode can be interpreted in terms of a cluster structure allowing long neck lengths at scission.