Characterization of the multifragment decay channel in highly excited nuclei. Progress report, March 15, 1992--September 14, 1993

Technical Report · Thu Oct 01 00:00:00 EDT 1992

DOI:https://doi.org/10.2172/10124781· OSTI ID:10124781

de Souza, R T

Characteristics of multifragment decay in heavy-ion induced reactions at intermediate energies are explored. Evolution of the timescale for emission of intermediate mass fragments (IMF: 3{le}Z{le}20) is investigated. Fragments associated with central collisions in the reactions {sup 36}Ar + {sup 197}Au at E/A = 50, 80, and 110 MeV are emitted on an extremely fast timescale, {tau} {le} 75 fm/c, comparable to the transit time of the projectile past the target nucleus. With increasing incident energy, mean fragment emission times decrease, consistent with statistical decay from highly excited systems or fast dynamical processes. To examine the importance of expansion effects in multifragmentation, the transverse kinetic energy of fragments was investigated. Evidence for expansion effects in the system {sup 36}Ar + {sup 197}Au at E/A = 50, 80, and 110 MeV was indicated by the charge dependence of the mean isotropic kinetic energy. At the highest incident energy the data suggest the onset of volume emission. Construction and performance of low-threshold high-resolution detector telescopes is discussed. Three-body Coulomb trajectory calculations are being used to probe kinematical correlations associated with neck emission of IMFs during fission. Initial design and testing of position sensitive parallel plate avalanche counters for upcoming ternary fission experiments is discussed.

• Research Organization: Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry
• Sponsoring Organization: USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
• DOE Contract Number: FG02-92ER40714
• OSTI ID: 10124781
• Report Number(s): DOE/ER/40714-1; ON: DE93008048; CNN: Grant PHY-89-13815; Grant PHY-90-15957; Grant PHY-90-15255
• Resource Relation: Other Information: PBD: Oct 1992
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
GOLD 197 TARGET
ARGON 36 REACTIONS
NUCLEAR FRAGMENTATION
TERNARY FISSION
NUCLEAR REACTION KINETICS
TELESCOPE COUNTERS
PERFORMANCE
PROGRESS REPORT
GEV RANGE 01-10
ENERGY DEPENDENCE
KINETIC ENERGY
663450
663580
663470
440103
HEAVY-ION-INDUCED REACTIONS AND SCATTERING
A = 190-219
FISSION
NUCLEAR SPECTROSCOPIC INSTRUMENTATION