Special properties of²⁶⁴Fm and of atomic clusters emitting singly charged trimers

Neutron-rich 264 Fm is an ideal cold fissioning nucleus leading to two identical doubly magic fragments 132 Sn. It posses the unique property of having a deep minimum of the shell correction energy at the same mass asymmetry η = 0 as the minimum of the LDM deformation energy. We illustrate this property by comparison with the superheavy nucleus 294 118, the cluster emitter 222 Ra and the light α-decaying nucleus 106 Te. On the other hand, it was experimentally proven that the most important yield in fission of charged metallic atomic clusters is usually obtained when the light fragment is a singly charged trimer (the analog of an α-particle with the magic number of delocalized electrons n e = 2). Our calculations for the fission of Ag 2+ 12 , as well as for the fission of Cs 2+ 24 , Cs 3+ 45 , Cs 4+ 64 , Cs 5+ 99 , Cs 8+ 208 and Cs 10+ 276 show that in this case both the shell corrections and the LDM deformation energy have minima at the same mass asymmetry which corresponds to the trimer emission. Consequently, charged metallic clusters are ideal emitters of α-clusters.