Sequential character of low-energy ternary and quaternary nuclear fission
| Autor: | A. O. Bulychev, S. G. Kadmensky |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Physics
Nuclear and High Energy Physics Fission products Cluster decay Fissile material 010308 nuclear & particles physics Fission media_common.quotation_subject Nuclear Theory 01 natural sciences Asymmetry Atomic and Molecular Physics and Optics Nuclear physics Nuclear fission 0103 physical sciences Neutron Atomic physics Nuclear Experiment 010306 general physics Ternary operation media_common |
| Zdroj: | Physics of Atomic Nuclei. 79:793-797 |
| ISSN: | 1562-692X 1063-7788 |
| DOI: | 10.1134/s1063778816050112 |
| Popis: | An analysis of low-energy true ternary (quaternary) nuclear fission leads to the conclusion that these fission modes have a sequential two-step (three-step) character such that the emission of a third particle (third and fourth particles) and the separation of fission fragments occur at distinctly different instants, in contrast to the simultaneous emergence of all fission products in the case of onestep ternary (quaternary) fission. This conclusion relies on the following arguments. First, the emission of a third particle (third and fourth particles) from a fissile nucleus is due to a nonevaporative mechanism associated with a nonadiabatic character of the collective deformation motion of this nucleus at the stages preceding its scission. Second, the axial symmetry of the deformed fissile compound nucleus and the direction of its symmetry axis both remain unchanged at all stages of ternary (quaternary) fission. This circumstancemakes it possible to explain themechanism of the appearance of observed anisotropies and T — odd asymmeries in the angular distributions of products of ternary (quaternary) nuclear fission. Third, the T —odd asymmetry discovered experimentally in ternary nuclear fission induced by cold polarized neutrons obeys the T —invariance condition only in the case of a sequential two-step (three-step) character of true ternary (quaternary) nuclear fission. At the same time, this asymmetry is not a T —invariant quantity in the case of the simultaneous emission of products of true ternary (quaternary) nuclear fission from the fissile compound nucleus. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|