Fission properties of heavy and superheavy nuclei

Calculations have been carried out to estimate the total fragment kinetic energies EK, total fragment excitation energies Ex, and approximate total number of neutrons ν emitted in the binary fission of heavy and superheavy nuclei. The kinetic energy calculations are based on a static scission model reported earlier for fissioning nuclei in the actinide region. The total energy release Q is calculated from a recent mass formula of Seeger, and the total excitation energy is obtained from the difference, Ex = Q − EK. The results show a strong peak in EK(A)[A = compound nucleus mass number] and a corresponding minimum in Ex(A), at A ≈ 264, corresponding to fission into two nearly double-magic (Z ≈ 50, N ≈ 82) fragments. Our predictions of EK, Ex, and ν disagree sharply with the liquid-drop predictions in the range 255 ⪅ A ⪅ 290. It appears from these results that kinetic energy measurements do not provide an unambiguous test for superheavy nuclei, while measurements of ν, if ν ⪆ 5, seem to provide such a test.