Mechanisms for light charged particle emission in the reactions 247 and 337 MeV /sup 40/Ar+/sup nat/Ag

Journal Article · Wed Jun 01 04:00:00 EDT 1988 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.37.2540· OSTI ID:5185894

Lacey, R; Ajitanand, N N; Alexander, J M; de Castro Rizzo, D M; Peaslee, G F; Vaz, L C; Kaplan, M; Kildir, M; La Rana, G; Moses, D J; others, and

Light charged particles from the reactions 247 and 337 MeV /sup 40/Ar+/sup nat/Ag have been measured in singles and in coincidence with fission-like products. Most of the /sup 1/H and /sup 4/He in coincidence with fusion-fission and quasifission can be accounted for by evaporation from the composite nucleus or by the fragments. Multiplicities are determined for /sup 1/H and /sup 4/He in association with evaporation residues, fusion-fission, and quasifission. The probability for composite nucleus emission decreases with increasing spin zone of the emitter and gives a view of the role of emitter lifetime. The ratio of composite-nucleus multiplicities for quasifissionfusion-fission is about 12 ((14) for 337 MeV /sup 40/Ar (247 MeV /sup 40/Ar) which implies a similar ratio for the lifetimes of the respective composite nuclei between thermalization and scission. Energy spectra and angular distributions of particles (in coincidence with fusion-fission and quasifission) are consistent with emission from a strongly distorted nuclear system en route toward scission. Prethermalization emission of /sup 4/He is observed at 10/sup 0/ in comparable amounts for peripheral collisions (quasifission and fusion-fission) and for central collisions.

• Research Organization: Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794
• OSTI ID: 5185894
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 37:6; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651720* -- Nuclear Properties & Reactions
A=90-149
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
ARGON 40 REACTIONS
CHARGED-PARTICLE REACTIONS
COINCIDENCE METHODS
COUNTING TECHNIQUES
DISTRIBUTION
ELEMENTS
ENERGY RANGE
FISSION
HEAVY ION REACTIONS
LIFETIME
MATHEMATICAL MODELS
METALS
MEV RANGE
MEV RANGE 100-1000
MULTIPLICITY
NUCLEAR MODELS
NUCLEAR REACTIONS
QUASI-FISSION
SCISSION-POINT MODEL
SILVER
TRANSITION ELEMENTS