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

Technical Report · Sat May 01 04:00:00 EDT 1982

DOI:https://doi.org/10.2172/5019498· OSTI ID:5019498

Sobotka, L G

The emission of alpha particles in coincidence with the most deeply inelastic heavy-ion reactions has been studied for /sup 181/Ta/sup +/ /sup 165/Ho at 1354 MeV laboratory energy and /sup nat/Ag + /sup 84/Kr at 664 MeV. 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 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 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 form the 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 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: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5019498
• Report Number(s): LBL-13863; ON: DE82018519
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA PARTICLES
ALPHA SPECTRA
ANGULAR DISTRIBUTION
ANGULAR MOMENTUM
CHARGED PARTICLES
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DATA
DEEP INELASTIC HEAVY ION REACTIONS
DIFFERENTIAL CROSS SECTIONS
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY
EXPERIMENTAL DATA
GAMMA RADIATION
HEAVY ION REACTIONS
HOLMIUM 165 REACTIONS
INFORMATION
IONIZING RADIATIONS
KINETIC ENERGY
KRYPTON 84 REACTIONS
METALS
NUCLEAR FRAGMENTS
NUCLEAR REACTIONS
NUMERICAL DATA
PARTICLE PROPERTIES
RADIATIONS
SILVER
SPECTRA
SPIN
TANTALUM 181 TARGET
TARGETS
TRANSITION ELEMENTS