MASS AND CHARGE YIELD CALCULATIONS FOR COLD FRAGMENTATION OF ACTINIDE NUCLEI

Cold fission is defined as a process of nuclear fragmentation leading only to low-excited final nuclei. We present a dynamical model for the cold fragmentations, in the frame of which we estimate the relative yields for the production of pairs of fragments by the penetrability through the potential barrier, in analogy with cluster decays. A supplementary beta-stretching polarization is assumed for the low-excited fragments. A single set of fragment ground-state deformations is used together with liquid-drop mass and stiffness parameters for all the cases considered. The calculated mass and charge yields for the cold fission of some even-even and odd U and Th isotopes are in excellent agreement with the available experimental data.