Sequential character of low-energy ternary and quaternary nuclear fission

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 d...

Full description

Saved in:
Bibliographic Details
Published in:Physics of atomic nuclei 2016-09, Vol.79 (5), p.793-797
Main Authors: Kadmensky, S. G., Bulychev, A. O.
Format: Article
Language:English
Subjects:
ANGULAR DISTRIBUTION
ANISOTROPY
ASYMMETRY
ATOMIC AND MOLECULAR PHYSICS
AXIAL SYMMETRY
Cleavage
COMPOUND NUCLEI
Deformation mechanisms
EMISSION
FISSION FRAGMENTS
FISSION PRODUCTS
Fragments
NEUTRONS
NUCLEAR DEFORMATION
Nuclear fission
NUCLEAR PHYSICS AND RADIATION PHYSICS
Nuclear weapons
Nuclei
Nuclei (nuclear physics)
Particle and Nuclear Physics
Physics
Physics and Astronomy
QUATERNARY FISSION
Symmetry
T INVARIANCE
TERNARY FISSION
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
ISSN:1063-7788
1562-692X
DOI:10.1134/S1063778816050112