A study of light charged-particle emission in the reaction: 480 MeV sup 56 Fe + @Ag

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6096754

Peaslee, G F

Inclusive and exclusive measurements of light charged particles ({sup 1,2,3}H and {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 1}H and {sup 4}He in coincidence with a heavy fragment is attributed to one 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 (fission-fragment-like and deeply-inelastic) at two different trigger fragment. For {theta}{sub TR}= 26{degree}, the multiplicity of light particles emitted from the composite nuclear prior to scission is {approx}2/3 for the fission-like fragments, compared, to {approx}1/3 for the deeply-inelastic fragments. This decrease implies a corresponding decrease ({approx}1/2) in the composite system lifetime, between the two processes. Energy and angular distributions of the coincident light particles indicate extensive emission from a strongly deformed composite system, such as that of a system en route to scission. Pre-thermalized and near-scission emission of {sup 4}He is also identified at specific laboratory angles in the forward hemisphere. The evaporation residues, which comprise less than 10% of the total reaction cross section, contribute between 30% and 40% of the inclusive light particle production. By requiring a coincidence between one {sup 4}He and a {sup 1}H, or a second {sup 4}He particle, one is able to select predominately these highly-excited evaporation residue emitters.

• Research Organization: State Univ. of New York, Stony Brook, NY (USA)
• OSTI ID: 6096754
• Country of Publication: United States
• Language: English

Related Subjects

651720* -- Nuclear Properties & Reactions
A=90-149
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ARGON
CHARGED-PARTICLE REACTIONS
DEEP INELASTIC HEAVY ION REACTIONS
ELEMENTS
EMISSION
ENERGY RANGE
ENERGY SPECTRA
EVAPORATION MODEL
EVEN-EVEN NUCLEI
FLUIDS
GASES
HEAVY ION REACTIONS
HELIUM 4
HELIUM ISOTOPES
HYDROGEN
IRON 56 REACTIONS
ISOTOPES
LIGHT NUCLEI
MATHEMATICAL MODELS
MEV RANGE
MEV RANGE 100-1000
NONMETALS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
PARTICLE PRODUCTION
QUASI-FISSION
RARE GASES
SCISSION-POINT MODEL
SPECTRA
STABLE ISOTOPES