Study of many-nucleon correlations in32S as a model for fragment shell effects in fission

The formation and break-up of substructures is studied in³²S as a calculable microscopic model for analogous long-range many-nucleon correlations in the fission of actinides. The calculations are performed for alpha-cluster wave functions with Volkov and Brink-Boeker interaction allowing forα,¹²C,¹⁶O and²⁰Ne clustering. It turns out that the correlated motion of large magic numbers of nucleons in two groups (¹⁶O+¹⁶O) is energetically favorable already at relatively small deformations. In the second minimum the¹⁶O+¹⁶O substructure occurs with high probability (about 80%). In analogy to these results the “pre-formation” of fragments and “fragment shell” effects occuring in the fission of actinides are explained in terms of probability statements for the formation of the corresponding heavy clusters in the many-body wave function.