Sources of light-charged-particle emission in the reaction 480 MeV /sup 56/Fe+/sup nat/Ag

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

DOI:https://doi.org/10.1103/PhysRevC.38.1730· OSTI ID:6762497

Peaslee, G F; Ajitanand, N N; Alexander, J M; Guerreau, D; Lacey, R; Vaz, L C; Kaplan, M; Kildir, M; Moses, D J; Logan, D; others, and

Inclusive and exclusive measurements of light-charged particles (/sup 1,2,3/H,/sup 4/He) and heavy fragments have been made for the reaction 480 MeV /sup 56/Fe+/sup nat/Ag. The backward hemisphere emission of /sup 4/He and /sup 1/H in coincidence with a heavy fragment can be well described by evaporative emission from a combination of three sources: the detected fragment, the undetected fragment, and the composite system prior to scission. Multiplicities for each of these sources are determined for two coincident fragment groups: a fusion-fission-like group and a deeply-inelastic-reaction group. These multiplicities have also been studied at two angles for the trigger fragment (theta/sub TR/ = 26/sup 0/ and 50/sup 0/). For theta/sub TR/ = 26/sup 0/ the multiplicity of the light-charged particles (/sup 1/H or /sup 4/He) emitted from the composite nuclear system (i.e., prior to scission) is approx. =(2/3 for the fusion-fission-like fragments, compared to approx. =(1/3 for the deeply inelastic reactions. This decrease implies that the deeply inelastic reactions occur in approx. =(1/2 the time required for fission reactions. For the deeply inelastic reactions, these multiplicities change with trigger angle. This result also suggests that the lifetime of the composite system exerts some control on the extent of evaporative particle emission. Energy and angular distributions of the coincident light particles suggest extensive emission from a strongly deformed composite system, such as that of a system en route to scission. Low-energy /sup 4/He particles at forward angles, which cannot be attributed to evaporation, exhibit a dependence on the angle with respect to the scission axis. This result is attributed to emission that occurs very near to the instant of scission.

• Research Organization: Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794
• OSTI ID: 6762497
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 38:4; 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
ACCELERATORS
ALPHA PARTICLES
ANGULAR DISTRIBUTION
BARYONS
CHARGED PARTICLES
CHARGED-PARTICLE REACTIONS
COINCIDENCE SPECTROMETRY
COMPOUND-NUCLEUS REACTIONS
DEEP INELASTIC SCATTERING
DEUTERONS
DISTRIBUTION
ELEMENTARY PARTICLES
ELEMENTS
ENERGY RANGE
ENERGY SPECTRA
EVAPORATION MODEL
FERMIONS
FISSION
FRAGMENTATION
HADRONS
HEAVY ION ACCELERATORS
HEAVY ION FUSION REACTIONS
HEAVY ION REACTIONS
HILACS
INCLUSIVE INTERACTIONS
INELASTIC SCATTERING
INTERACTIONS
IRON 56 REACTIONS
LEPTON-BARYON INTERACTIONS
LEPTON-HADRON INTERACTIONS
LEPTON-NUCLEON INTERACTIONS
LINEAR ACCELERATORS
MATHEMATICAL MODELS
METALS
MEV RANGE
MEV RANGE 100-1000
MULTIPLICITY
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEONS
PARTICLE INTERACTIONS
PROTONS
SCATTERING
SILVER
SPECTRA
SUPERHILAC
TRANSITION ELEMENTS
TRITONS