Fission before {ital K} equilibration
- China Institute of Atomic Energy, Beijing 102413 (China)
It is demonstrated experimentally that the reaction systems on the different side of Businaro-Gallone critical mass asymmetry ({alpha}{sub BG}) have different characteristics in fusion-fission reactions. Fragment anisotropies resulting from the reactions with the entrance-channel mass asymmetry {alpha}{approx_gt}{alpha}{sub BG} are well described by the saddle-point transition-state model. However, the measured fragment anisotropies for the systems with {alpha}{lt}{alpha}{sub BG} are obviously greater than the predictions of this model at subbarrier and near-barrier energies and gradually tend to coincide with the theoretical expectations as the bombarding energy increasing over fusion barrier. These observations have led us to a suggestion of preequilibrium fission for low angular momentum. The predictions of such a preequilibrium fission model are compared with the available experimental data and it is shown that they can satisfactorily reproduce the observed trends as a function of the bombarding energy for the reaction systems studied. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 286817
- Journal Information:
- Physical Review, C, Vol. 54, Issue 2; Other Information: PBD: Aug 1996
- Country of Publication:
- United States
- Language:
- English
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