Light-charged-particle emission in /sup 40/Ar-induced reactions: A probe of the very early evolution of the collisions

Journal Article · Mon Sep 01 04:00:00 EDT 1980 · Phys. Rev., C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.22.1080· OSTI ID:5153100

Logan, D; Delagrange, H; Rivet, M F; Rajagopalan, M; Alexander, J M; Kaplan, M; Zisman, M S; Duek, E

Charged-particle emission was studied for the reactions 222, 274, and 340 MeV /sup 40/Ar+/sup 116/Sn, /sup 154/Sm, /sup 164/Dy, and /sup 197/Au. Energy and angular distributions were measured for H and He and angular distributions for Li, Be, B, C, N, and O, fissionlike fragments and evaporation residues. For H and He the data are consistent with a low-temperature evaporative component and a high-temperature forward peaked component. For Li through O the forward-peaked emission was studied for 340 MeV /sup 40/Ar only. The evaporation residue cross sections decrease strongly with increasing Z reflecting the increasing fissionability. However, the cross sections for /sup 1/H and /sup 4/He in coincidence with fission are essentially constant with Z. Coincidence measurements, energy spectra, and /sup 4/He//sup 1/H ratios indicate that most H/He evaporation precedes fission. This implies that the energy thermalization is very rapid indeed and that the light particle spectra can probe the very early history of the composite systems.

• Research Organization: Department of Chemistry, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213
• OSTI ID: 5153100
• Journal Information: Phys. Rev., C; (United States), Journal Name: Phys. Rev., C; (United States) Vol. 22:3; ISSN PRVCA
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALKALI METALS
ALKALINE EARTH METALS
ANGULAR DISTRIBUTION
ARGON 40 REACTIONS
BERYLLIUM
BORON
CARBON
CHARGED-PARTICLE REACTIONS
COINCIDENCE SPECTROMETRY
COMPOUND-NUCLEUS REACTIONS
CRYOGENIC FLUIDS
DISTRIBUTION
DYSPROSIUM 164 TARGET
ELEMENTS
ENERGY RANGE
ENERGY SPECTRA
EVAPORATION MODEL
EVEN-EVEN NUCLEI
FISSION
FLUIDS
GOLD 197 TARGET
HEAVY ION REACTIONS
HELIUM 4
HELIUM ISOTOPES
HYDROGEN 1
HYDROGEN ISOTOPES
ISOTOPES
LIGHT NUCLEI
LITHIUM
MATHEMATICAL MODELS
METALS
MEV RANGE
MEV RANGE 100-1000
NITROGEN
NONMETALS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
ODD-EVEN NUCLEI
SAMARIUM 154 TARGET
SEMIMETALS
SPECTRA
STABLE ISOTOPES
TARGETS
TIN 116 TARGET