Measurements of time delays for projectile-like fragments in the reaction sup 40 Ar+Ge at 44 MeV/nucleon

Journal Article · Mon Jan 01 00:00:00 EST 1990 · Physical Review, C (Nuclear Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevC.41.139· OSTI ID:6849040

Gomez del Campo, J ^[1]; Barrette, J; Dayras, R A; Wieleczko, J P; Pollacco, E C ^[2]; Saint-Laurent, F ^[3]; Toulemonde, M ^[4]; Neskovic, N; Ostojic, R ^[5]

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1. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (USA)
2. Servicie de Physique Nucleaire-Basse Energie, Centre d'Etudes Nucleaires de Saclay, 91191 Gif-sur-Yvette CEDEX, (France)
3. Grand Accelerateur National d'Ions Lourds, Bote Postale 5027, 14021 Caeen CEDEX, (France)
4. Centre Interdisciplinaire de Recherche avec des Ions Lourds, Bote Postale 5133, 14040 Caeen CEDEX, (France)
5. Boris Kidric Institute of Nuclear Sciences, Belgrade, (Yugoslavia)

Crystal-blocking angular distributions have been measured for projectile-like fragments produced in bombarding a 10-{mu}m Ge crystal with a 1.76-GeV {sup 40}Ar beam. Long time delays of the order of (6--12){times}10{sup {minus}18} s were extracted and gave a direct indication of important evaporation effects. The measured times can be reproduced using a broad distribution of primary fragments of the type predicted by the abrasion model, but with excitation energies from 15 to 50 MeV, which are higher than predicted by the model. The measured times can also be reproduced assuming a narrow primary mass distribution with highly excited fragments having excitation energies of about 150 MeV.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6849040
• Journal Information: Physical Review, C (Nuclear Physics); (USA), Vol. 41:1; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ARGON 40 REACTIONS
NUCLEAR FRAGMENTATION
GERMANIUM
ANGULAR DISTRIBUTION
EVAPORATION MODEL
GANIL CYCLOTRON
GEV RANGE 01-10
MASS SPECTRA
TIME DELAY
ACCELERATORS
CHARGED-PARTICLE REACTIONS
DISTRIBUTION
ELEMENTS
ENERGY RANGE
GEV RANGE
HEAVY ION ACCELERATORS
HEAVY ION REACTIONS
MATHEMATICAL MODELS
METALS
NUCLEAR MODELS
NUCLEAR REACTIONS
SPECTRA
651620* - Nuclear Properties & Reactions
A=59-89
Experimental