Fission mechanisms in the carbon-induced fission of uranium

摘要

The conventional radiochemical technique was applied to the C-12-induced fission of U-238 at incident energies below and above the borderline for the appearance of fast fission. It supplies information on the charge dispersion and distribution of fission products in addition to the mass distribution for isolation of fast fission from ordinary fusion fission. The resulted width of charge dispersion was independent of A except for the case of the 140 MeV incident energy, where the widths at far-asymmetric mass region were definitely large compared to the normal value. On the other hand, the observed variances of mass distribution change around the threshold energy for fast fission more drastically than prediction by the model assuming that they are controlled by the stiffness coefficient and the temperature. We conclude that both results suggest the appearance of far-asymmetric mass distribution associated with the set-in of fast fission. (C) 1998 Elsevier Science S.A. [References: 27]