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Title: Sequential character of low-energy ternary and quaternary nuclear fission

Abstract

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 truemore » 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.« less

Authors:
;  [1]
  1. Voronezh State University (Russian Federation)
Publication Date:
OSTI Identifier:
22612611
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Atomic Nuclei; Journal Volume: 79; Journal Issue: 5; Other Information: Copyright (c) 2016 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 74 ATOMIC AND MOLECULAR PHYSICS; ANGULAR DISTRIBUTION; ANISOTROPY; ASYMMETRY; AXIAL SYMMETRY; COMPOUND NUCLEI; EMISSION; FISSION FRAGMENTS; FISSION PRODUCTS; NEUTRONS; NUCLEAR DEFORMATION; QUATERNARY FISSION; T INVARIANCE; TERNARY FISSION

Citation Formats

Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru, and Bulychev, A. O. Sequential character of low-energy ternary and quaternary nuclear fission. United States: N. p., 2016. Web. doi:10.1134/S1063778816050112.
Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru, & Bulychev, A. O. Sequential character of low-energy ternary and quaternary nuclear fission. United States. doi:10.1134/S1063778816050112.
Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru, and Bulychev, A. O. Thu . "Sequential character of low-energy ternary and quaternary nuclear fission". United States. doi:10.1134/S1063778816050112.
@article{osti_22612611,
title = {Sequential character of low-energy ternary and quaternary nuclear fission},
author = {Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru and Bulychev, A. O.},
abstractNote = {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.},
doi = {10.1134/S1063778816050112},
journal = {Physics of Atomic Nuclei},
number = 5,
volume = 79,
place = {United States},
year = {Thu Sep 15 00:00:00 EDT 2016},
month = {Thu Sep 15 00:00:00 EDT 2016}
}