Contemporary presence of dynamical and statistical production of intermediate mass fragments in midperipheral 58 Ni + 58 Ni collisions at 30 MeV / nucleon
نویسندگان
چکیده
The 58 N i + 58 N i reaction at 30 MeV/nucleon has been experimentally investigated at the Superconducting Cyclotron of the INFN Laboratori Nazionali del Sud. In midperipheral collisions the production of massive fragments (4≤Z≤12), consistent with the statistical fragmentation of the projectile-like residue and the contemporary dynamical formation of a neck, joining projectile-like and target-like residues, has been observed. In particular it is shown that fragments coming from these different processes differ both in charge distribution and isotopic composition. The production of intermediate mass fragments (IMF, 3≤Z≤20) is the distinguishing feature of intermediate energy heavy ion collisions. A possible scenario for IMF emission involves the development of bulk instabilities in the nuclear matter, which lead to a statistical fragmentation. This is supported by several experimental results concerning both the decay of unique sources formed in central collisions and the disassembly of quasitarget (QT) and quasiprojectile (QP) in dissipative peripheral collisions [1,2].
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