Competition between fusion-fission and quasifission processes in the {sup 32}S+{sup 184}W reaction

Journal Article · Mon Mar 15 00:00:00 EDT 2010 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.81.034611· OSTI ID:21388889

Zhang, H Q; Zhang, C L; Lin, C J; Liu, Z H; Yang, F; Nasirov, A K; Mandaglio, G; Manganaro, M; Giardina, G ^[1]

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1. China Institute of Atomic Energy, Post Office Box 275, Beijing 102413 (China)

The angular distributions of fission fragments for the {sup 32}S+{sup 184}W reaction at center-of-mass energies of 118.8, 123.1, 127.3, 131.5, 135.8, 141.1, and 144.4 MeV are measured. The experimental fission excitation function is obtained. The anisotropy (A{sub exp}) is found by extrapolating each fission fragment angular distribution. The measured fission cross sections of the {sup 32}S+{sup 182,184}W reaction are decomposed into fusion-fission, quasifission, and fast-fission contributions by the dinuclear system model (DNS). The angular momentum distributions of the dinuclear system and compound nucleus calculated by the DNS model are used to reproduce the experimental capture and fusion excitation functions for both reactions and quantities K{sub 0}{sup 2}, <l{sup 2}>, and A{sub exp}, which characterize angular distributions of the fission products at the considered range of beam energy. The total evaporation residue excitation function for the {sup 32}S+{sup 184}W reaction calculated in the framework of the advanced statistical model is close to the available experimental data only up to about E{sub c.m.}approx =160 MeV. The underestimation of the experimental data at high excitation energies E{sub c.m.}>160 MeV is explained by the fact that the statistical model cannot reproduce the cross section of evaporation residues formed by the nonequilibrium mechanism, that is, without formation of the compound nucleus in the statistical equilibrium state.

• OSTI ID: 21388889
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 81, Issue 3; Other Information: DOI: 10.1103/PhysRevC.81.034611; (c) 2010 The American Physical Society; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
ANGULAR MOMENTUM
ANISOTROPY
BEAMS
CAPTURE
CENTER-OF-MASS SYSTEM
COMPETITION
COMPOUND NUCLEI
EQUILIBRIUM
EVAPORATION
EXCITATION
EXCITATION FUNCTIONS
FAST FISSION
FISSION FRAGMENTS
FISSION PRODUCTS
MEV RANGE 100-1000
NUCLEAR REACTIONS
QUASI-FISSION
RESIDUES
STATISTICAL MODELS
TUNGSTEN 182
TUNGSTEN 184
BARYON REACTIONS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
DISTRIBUTION
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EVEN-EVEN NUCLEI
FISSION
FUNCTIONS
HADRON REACTIONS
HEAVY ION REACTIONS
HEAVY NUCLEI
ISOTOPES
MATERIALS
MATHEMATICAL MODELS
MEV RANGE
NEUTRON REACTIONS
NUCLEAR FRAGMENTS
NUCLEI
NUCLEON REACTIONS
PHASE TRANSFORMATIONS
RADIOACTIVE MATERIALS
STABLE ISOTOPES
TUNGSTEN ISOTOPES