Time features of delayed neutrons and partial emissive-fission cross sections for the neutron-induced fission of {sup 232}Th nuclei in the energy range 3.2-17.9 MeV
The energy dependence of the relative abundances of delayed neutrons and the energy dependence of the half-lives of their precursors in the neutron-induced fission of {sup 232}Th nuclei in the energy range 3.2-17.9 MeV were measured for the first time. A systematics of the time features of delayed neutrons is developed. This systematics makes it possible to estimate the half-life of delayed-neutron precursors as a function of the nucleonic composition of fissile nuclei by using a single parameter set for all nuclides. The energy dependence of the partial cross sections for emissive fission in the reaction {sup 232}Th(n, f) was analyzed on the basis of data obtained for the relative abundances of delayed neutrons and the aforementioned half-lives and on the basis of the created systematics of the time features of delayed neutrons. It was shown experimentally for the first time that the decrease in the cross section after the reaction threshold in the fission of {sup 232}Th nuclei (it has a pronounced first-chance plateau) is not an exclusion among the already studied uranium, plutonium, and curium isotopes and complies with theoretical predictions obtained for the respective nuclei with allowance for shell, superfluid, and collective effects in the nuclear-level density and with allowance for preequilibrium neutron emission
- OSTI ID:
- 21426726
- Journal Information:
- Physics of Atomic Nuclei, Vol. 73, Issue 6; Other Information: DOI: 10.1134/S1063778810060013; Copyright (c) 2010 Pleiades Publishing, Ltd.; ISSN 1063-7788
- Country of Publication:
- United States
- Language:
- English
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ABUNDANCE
CROSS SECTIONS
CURIUM ISOTOPES
DELAYED NEUTRON PRECURSORS
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FISSILE MATERIALS
FISSION
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PLUTONIUM ISOTOPES
THEORETICAL DATA
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ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
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ELEMENTARY PARTICLES
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FERMIONS
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HADRONS
HEAVY NUCLEI
INFORMATION
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NUCLEAR REACTIONS
NUCLEI
NUCLEONS
NUMERICAL DATA
RADIOISOTOPES
SPONTANEOUS FISSION RADIOISOTOPES
THORIUM ISOTOPES
YEARS LIVING RADIOISOTOPES