Characterization of the multifragment decay channel in highly excited nuclei. [Indiana Univ. , Bloomington, Indiana]

Technical Report · Thu Oct 01 04:00:00 EDT 1992

DOI:https://doi.org/10.2172/6708659· OSTI ID:6708659

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: DOE; NSF; USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
• DOE Contract Number: FG02-92ER40714
• OSTI ID: 6708659
• Report Number(s): DOE/ER/40714-1; ON: DE93008048; CNN: PHY-89-13815; PHY-90-15957; PHY-90-15255
• Country of Publication: United States
• Language: English

Related Subjects

440103 -- Radiation Instrumentation-- Nuclear Spectroscopic Instrumentation
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
663450* -- Heavy-Ion-Induced Reactions & Scattering-- (1992-)
663470 -- Fission-- (1992-)
663580 -- Nuclear Mass Ranges-- A=190-219-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ARGON 36 REACTIONS
CHARGED-PARTICLE REACTIONS
DOCUMENT TYPES
ENERGY
ENERGY DEPENDENCE
ENERGY RANGE
FISSION
GEV RANGE
GEV RANGE 01-10
GOLD 197 TARGET
HEAVY ION REACTIONS
KINETIC ENERGY
KINETICS
NUCLEAR FRAGMENTATION
NUCLEAR REACTION KINETICS
NUCLEAR REACTIONS
PERFORMANCE
PROGRESS REPORT
REACTION KINETICS
TARGETS
TELESCOPE COUNTERS
TERNARY FISSION