Fission properties of heavy and superheavy nuclei

Abstract

Calculations have been carried out to estimate the total fragment kinetic energies E K, total fragment excitation energies E x, 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, E x = Q − E K. The results show a strong peak in E K( A)[ A = compound nucleus mass number] and a corresponding minimum in E x( A), at A ≈ 264, corresponding to fission into two nearly double-magic ( Z ≈ 50, N ≈ 82) fragments. Our predictions of E K, E x, 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.