Characteristics of Symmetric and Asymmetric Fission Modes as a Function of the Compound Nucleus Excitation in the Proton-Induced Fission of 233Pa, 239Np and 243Am

2007 ◽  
Author(s):  
M. Beresova ◽  
A. A. Bogatchev ◽  
O. Dorvaux ◽  
I. M. Itkis ◽  
M. G. Itkis ◽  
...  
Keyword(s):  
Compound Nucleus ◽  
Induced Fission ◽  
Asymmetric Fission

Symmetric and asymmetric fission modes in proton-induced fission at 660 MeV of 238U

2010 ◽  
Vol 73 (11) ◽  
pp. 1814-1819 ◽  
Author(s):  
A. R. Balabekyan ◽  
G. S. Karapetyan ◽  
N. A. Demekhina ◽  
J. Adam ◽  
K. Katovsky
Keyword(s):  
Induced Fission ◽  
Asymmetric Fission

scholarly journals Comparing fission-product yields from photon-induced fission of 240Pu and neutron-induced fission of 239Pu as a test of the Bohr hypothesis in nuclear fission

2020 ◽  
Vol 242 ◽  
pp. 01008
Author(s):  
Jack Silano ◽  
Anton Tonchev ◽  
Roger Henderson ◽  
Nicolas Schunck ◽  
Werner Tornow ◽  
...  
Keyword(s):  
Fission Product ◽  
Excitation Energy ◽  
Compound Nucleus ◽  
Nuclear Fission ◽  
Photon Beams ◽  
Fission Process ◽  
Product Yields ◽  
Fission Product Yields ◽  
Induced Fission ◽  
First Time

Fission product yields (FPYs) are a uniquely sensitive probe of the fission process, with well established dependence on the species of nucleus undergoing fission, its excitation energy and spin. Thus FPYs are well suited for testing Bohr’s hypothesis in the context of nuclear fission, which states that the decay of a compound nucleus with a given excitation energy, spin and parity is independent of its formation. Using FPYs, we have performed a new highprecision test of the combined effects of the entrance channel, spin and parity on the fission process from two of the most commonly used particles to induce fission neutrons and photons. The 239 Pu(n,f) reaction at En = 4.6 MeV and the 240 Pu(γ,f) reaction at Eγ = 11.2 MeV were used to produce a 240 Pu∗ compound nucleus with the same excitation energy. The FPYs from these two reactions were measured using quasimonoenergetic neutron beams from the TUNL’s FN tandem Van de Graaff accelerator and quasimonenergetic photon beams from the High Intensity γ-ray Source (HIγS) facility. The FPYs from these two reactions are compared quantitatively for the first time.

scholarly journals Dependence of the prompt fission γ-ray spectrum on the entrance channel of compound nucleus: Spontaneous vs. neutron-induced fission

2018 ◽  
Vol 782 ◽  
pp. 652-656 ◽  
Author(s):  
A. Chyzh ◽  
P. Jaffke ◽  
C.Y. Wu ◽  
R.A. Henderson ◽  
P. Talou ◽  
...  
Keyword(s):  
Compound Nucleus ◽  
Entrance Channel ◽  
Induced Fission ◽  
Γ Ray ◽  
Prompt Fission

Symmetric and asymmetric fission in electron induced fission of 232Th

1976 ◽  
Vol 260 (2) ◽  
pp. 287-291 ◽  
Author(s):  
J. Aschenbach ◽  
G. Fiedler ◽  
E. Konecny
Keyword(s):  
Induced Fission ◽  
Asymmetric Fission

scholarly journals Investigation of the heavy nuclei fission with anomalously high values of the fission fragments total kinetic energy

2018 ◽  
Vol 169 ◽  
pp. 00011
Author(s):  
Vitaly Khryachkov ◽  
Andrei Goverdovskii ◽  
Vladimir Ketlerov ◽  
Vecheslav Mitrofanov ◽  
Alexei Sergachev
Keyword(s):  
Kinetic Energy ◽  
Compound Nucleus ◽  
Fission Fragment ◽  
Total Kinetic Energy ◽  
Fast Neutrons ◽  
Heavy Nuclei ◽  
Fission Fragments ◽  
Close Analysis ◽  
Fragment Distribution ◽  
Induced Fission

Binary fission of 232Th and 238U induced by fast neutrons were under intent investigation in the IPPE during recent years. These measurements were performed with a twin ionization chamber with Frisch grids. Signals from the detector were digitized for further processing with a specially developed software. It results in information of kinetic energies, masses, directions and Bragg curves of registered fission fragments. Total statistics of a few million fission events were collected during each experiment. It was discovered that for several combinations of fission fragment masses their total kinetic energy was very close to total free energy of the fissioning system. The probability of such fission events for the fast neutron induced fission was found to be much higher than for spontaneous fission of 252Cf and thermal neutron induced fission of 235U. For experiments with 238U target the energy of incident neutrons were 5 MeV and 6.5 MeV. Close analysis of dependence of fission fragment distribution on compound nucleus excitation energy gave us some explanation of the phenomenon. It could be a process in highly excited compound nucleus which leads the fissioning system from the scission point into the fusion valley with high probability.

Development of a “fission-proxy” method for the measurement of 14-MeV neutron fission yields

2018 ◽  
Vol 106 (8) ◽  
pp. 627-630
Author(s):  
Narek Gharibyan ◽  
Ken Moody ◽  
Scott Tumey ◽  
Tom Brown ◽  
Pat Grant ◽  
...  
Keyword(s):  
Compound Nucleus ◽  
Reaction Pathway ◽  
Fission Products ◽  
Quantitative Comparison ◽  
Fission Yield ◽  
Neutron Fission ◽  
New Approach ◽  
Independence Hypothesis ◽  
Induced Fission ◽  
Fission Yields

Abstract Relative fission-yield measurements were made for 50 fission products from 25.6±0.5 MeV α-induced fission of Th-232. Quantitative comparison of these experimentally measured yields with the evaluated fission yields from 14-MeV neutrons on U-235 demonstrates the application of the Bohr-independence hypothesis for measuring fission yields. As optimum particle-target configurations may be impossible or compromised at a given facility, this new approach, fission-proxy, allows the measurement of fission yields for a given compound nucleus from an alternate reaction pathway since formation and subsequent decay are independent processes.

Some Chain Yields in the Asymmetric Fission of Thorium-232 Induced by 3 and 14.7 MeV Neutrons

1968 ◽  
Vol 9 (2-3) ◽  
Author(s):  
S. J. Lyle ◽  
G. R. Martin ◽  
Md. M. Rahman
Keyword(s):  
Excitation Energy ◽  
Initial Excitation ◽  
Induced Fission ◽  
Secondary Neutrons ◽  
Thorium 232 ◽  
Asymmetric Fission ◽  
Good Agreement

SummaryCumulative chain yields for masses 83, 84, 97, 99, 129, 132, 143 and 145 are reported for fission induced in thorium-232 by 3 MeV neutrons. Yields for 14.7 MeV neutron induced fission for the same masses except 132 and 143 but including 131 were also measured. At each initial excitation energy the number of secondary neutrons emitted by several pairs of complementary fragments was calculated; values from 2.3 to 2.4 (at 3 MeV) and 3.6 to 4.0 (at 14 MeV) in good agreement with average published values were obtained. An assessment of the positions of the light and heavy peak maxima suggests that the latter shifts more than the former towards lower masses with increase in initial excitation energy. Implications of this result are discussed.

Compound nucleus formation in the 14N + 16O system

1977 ◽  
Vol 38 (10) ◽  
pp. 1179-1183 ◽  
Author(s):  
C. Volant ◽  
M. Conjeaud ◽  
S. Harar ◽  
E.F. Da Silveira
Keyword(s):  
Compound Nucleus ◽  
Nucleus Formation ◽  
Compound Nucleus Formation
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