ROTATING BUBBLE AND TOROIDAL NUCLEI AND FRAGMENTATION

The energy of rotating bubble and toroidal nuclei predicted to be form ed in central heavy-ion collisions at intermediate energies is calcula ted within the generalized rotating liquid drop model. The potential b arriers standing in these exotic deformation paths are compared with t he three-dimensional and plane-fragmentation barriers, Metastable bubb le-like minima only appear at very high angular momentum and above the three-dimensional fragmentation, barriers, In the toroidal deformatio n path of the heaviest systems exists a large potential pocket localis ed below the plane-fragmentation barriers, This might allow the tempor ary survival of heavy nuclear toroids before the final clusterisation induced by the surface and proximity tension.