Investigation of the {sup 208}Pb({sup 18}O, f) fission reaction: Mass-energy distributions of fission fragments and their correlation with the gamma-ray multiplicity

Journal Article · Sun Jun 15 04:00:00 EDT 2008 · Physics of Atomic Nuclei

DOI:https://doi.org/10.1134/S1063778808060021· OSTI ID:21402570

Itkis, M G; Kondratiev, N A; Pashkevich, V V; Pokrovsky, I V; Salamatin, V S ^[1]; Chubarian, G G ^[2]

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1. Joint Institute for Nuclear Research (Russian Federation)
2. Texas A and M University, Cyclotron Institute (United States)

The mass-energy distributions of fragments originating from the fission of the compound nucleus {sup 226}Th and their correlations with the multiplicity of gamma rays emitted from these fragments are measured and analyzed in {sup 18}O + {sup 208}Pb interaction induced by projectile oxygen ions of energy in the range E{sub lab} = 78-198.5 MeV. Manifestations of an asymmetric fission mode, which is damped exponentially with increasing E{sub lab}, are demonstrated. Theoretical calculations of fission valleys reveal that only two independent valleys, symmetric and asymmetric, exist in the vicinity of the scission point. The dependence of the multiplicity of gamma rays emitted from both fission fragments on their mass, M{sub {gamma}}(M), has a complicated structure and is highly sensitive to shell effects in both primary and final fragments. A two-component analysis of the dependence M{sub {gamma}}(M) shows that the asymmetric mode survives in fission only at low partial-wave orbital angular momenta of compound nuclei. It is found that, for all E{sub lab}, the gamma-ray multiplicity M{sub {gamma}}as a function of the total kinetic energy (TKE) of fragments, M{sub {gamma}}(TKE), decreases linearly with increasing TKE. An analysis of the energy balance in the fission process at the laboratory energy of E{sub lab} = 78 MeV revealed the region of cold fission of fragments whose total kinetic energy is TKE {approx}Q{sub max}.

• OSTI ID: 21402570
• Journal Information: Physics of Atomic Nuclei, Journal Name: Physics of Atomic Nuclei Journal Issue: 6 Vol. 71; ISSN 1063-7788; ISSN PANUEO
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
ANGULAR MOMENTUM
ASYMMETRY
CHARGED PARTICLES
COLD FISSION
COMPOUND NUCLEI
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ENERGY
ENERGY BALANCE
ENERGY RANGE
ENERGY SPECTRA
EVEN-EVEN NUCLEI
FISSION
FISSION FRAGMENTS
GAMMA RADIATION
HEAVY NUCLEI
INTERACTIONS
IONIZING RADIATIONS
IONS
ISOTOPES
KINETIC ENERGY
LEAD 208
LEAD ISOTOPES
LIGHT NUCLEI
MASS DISTRIBUTION
MEV RANGE
MINUTES LIVING RADIOISOTOPES
MULTIPLICITY
NUCLEAR FRAGMENTS
NUCLEAR REACTIONS
NUCLEI
ORBITAL ANGULAR MOMENTUM
OXYGEN 18
OXYGEN IONS
OXYGEN ISOTOPES
PARTIAL WAVES
PARTICLE INTERACTIONS
RADIATIONS
RADIOISOTOPES
SPATIAL DISTRIBUTION
SPECTRA
STABLE ISOTOPES
SYMMETRY
THORIUM 226
THORIUM ISOTOPES