Anomalous anisotropy of fission fragments in near- and sub-barrier complete fusion-fission reactions of [sup 16]O+[sup 232]Th, [sup 19]F+[sup 232]Th, and [sup 16]O+[sup 238]U

Journal Article · Tue Feb 01 04:00:00 EST 1994 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.49.926· OSTI ID:5192418

Zhang, H; Liu, Z; Xu, J; Qian, X; Qiao, Y; Lin, C; Xu, K ^[1]

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1. China Institute of Atomic Energy, Beijing, 102413 (China)

Using the fragment folding angle technique, the complete fusion-fission is separated from the transfer-induced fission. The cross sections of the complete fusion-fission and fragment angular distributions for the systems of [sup 16]O+[sup 232]Th, [sup 19]F+[sup 232]Th, and [sup 16]O+[sup 238]U at near- and sub-barrier energies have been measured. The observed fission excitation functions can be fitted very well by coupled-channels theory calculations. It is found that fragments from complete fusion fission show a smaller angular anisotropy as compared with our previous measurements in which the transfer-induced fission component was not excluded. However, the measured angular anisotropies of complete fusion-fission are obviously greater than expected on the basis of theoretical models in which the effect of prefission neutron emission was taken into account. Also the peak in the variation of the anisotropy with incident energy still persists in the [sup 19]F+[sup 232]Th case.

• OSTI ID: 5192418
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Journal Name: Physical Review, C (Nuclear Physics); (United States) Vol. 49:2; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

663450* -- Heavy-Ion-Induced Reactions & Scattering-- (1992-)
663590 -- Nuclear Mass Ranges-- A=220 & Above-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
ANISOTROPY
CHARGED-PARTICLE REACTIONS
COUPLED CHANNEL THEORY
CROSS SECTIONS
DISTRIBUTION
ENERGY RANGE
FISSION
FISSION FRAGMENTS
FLUORINE 19 REACTIONS
HEAVY ION FUSION REACTIONS
HEAVY ION REACTIONS
MEV RANGE
MEV RANGE 10-100
NUCLEAR FRAGMENTS
NUCLEAR REACTIONS
OXYGEN 16 REACTIONS
TARGETS
THORIUM 232 TARGET
URANIUM 238 TARGET