Light particle emission as a probe of the rotational degrees of freedom in deep-inelastic reactions

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1982

OSTI ID:5990265

Sobotka, L G

The emission of ..cap alpha.. particles in coincidence with the most deeply inelastic heavy-ion reactions has been studied for /sup 181/Ta + /sup 165/Ho at 1354 MeV laboratory energy and /sup nat/Ag + /sup 84/Kr at 664 MeV. ..cap alpha.. particle energy spectra and angular distributions, in coincidence with a projectile-like fragment, were acquired both in the reaction plane and out of the reaction plane at a fixed in-plane angle. The in-plane data for both systems are employed to show that the bulk of the ..cap alpha.. particles in coincidence with the deep-inelastic exit channel can be explained by evaporation from the fully accelerated fragments. Average velocity diagrams, ..cap alpha..-particle energy spectra as a function of angle in several rest frames, and ..cap alpha..-particle angular distributions are presented. The out-of-plane ..cap alpha.. particle angular distributions and the ..gamma..-ray multiplicities are used to study the transfer and partitioning of angular momentum between the two fragments. For the /sup nat/Ag + /sup 84/Kr system, individual fragment spins are extracted from the ..cap alpha.. particle angular distributions as a function of mass asymmetry while the sum of the fragment spins is derived from the ..gamma..-ray multiplicities. These data, together with the fragment kinetic energies, are consistent with rigid rotation of an intermediate complex consisting of two substantially deformed spheroids in near proximity. These data also indicate that some angular momentum fractionation exists at the largest asymmetries examined. Out-of-plane ..cap alpha.. particle distributions, ..gamma..-ray multiplicities, fragment spins as well as the formalism for the spin evaluation at various levels of sophistication are presented.

• Research Organization: California Univ., Berkeley (USA)
• OSTI ID: 5990265
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA PARTICLES
ANGULAR DISTRIBUTION
CHARGED PARTICLES
CHARGED-PARTICLE REACTIONS
DEEP INELASTIC HEAVY ION REACTIONS
DISTRIBUTION
ELEMENTS
ENERGY LEVELS
ENERGY RANGE
EXCITED STATES
GEV RANGE
GEV RANGE 01-10
HEAVY ION REACTIONS
HOLMIUM 165 REACTIONS
KRYPTON 84 REACTIONS
METALS
MEV RANGE
MEV RANGE 100-1000
NUCLEAR REACTIONS
ROTATIONAL STATES
SILVER
TANTALUM 181 TARGET
TARGETS
TRANSITION ELEMENTS