Medium energy. gamma. rays in nuclear reactions
A model is formulated for the prediction of medium energy ..gamma.. rays in light-ion-induced collisions. We assume a semidirect reaction whereby the giant dipole resonance is excited in the preequilibrium relaxation process. Detailed balance is used to invert experimental photon absorption cross sections to a ..gamma..-ray emission rate, and this emission rate is incorporated into the hybrid model for pre- equilibrium decay. Comparisons of calculated and experimental ..gamma..-ray spectra from 14 MeV neutron-induced reactions give reasonably good agreement, as do comparisons with 27 MeV /sup 3/He- and ..cap alpha..-induced reactions. An np..gamma.. bremsstrahlung calculation underpredicts these same data by a large amount. Our findings are consistent with an interpretation that the giant dipole resonance collective excitation may be induced by single particle-hole transitions in the preequilibrium relaxation process, and may contribute to the high-energy tail of observed ..gamma..-ray emission spectra.
- Research Organization:
- Physics Department, Lawrence Livermore National Laboratory, Livermore, California 94550
- OSTI ID:
- 6906889
- Journal Information:
- Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 38:3; ISSN PRVCA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Coupled-Channel Models of Direct-Semidirect Capture via Giant-Dipole Resonances
Photoproton decay of the /sup 45/Sc giant dipole resonance
Related Subjects
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA REACTIONS
BARYON REACTIONS
BREMSSTRAHLUNG
CHARGED-PARTICLE REACTIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY RANGE
GAMMA RADIATION
GIANT RESONANCE
HADRON REACTIONS
HELIUM 3 REACTIONS
IONIZING RADIATIONS
LANTHANUM 139 TARGET
METALS
MEV RANGE
MEV RANGE 10-100
NEUTRON REACTIONS
NIOBIUM 93 TARGET
NUCLEAR REACTIONS
NUCLEON REACTIONS
PRECOMPOUND-NUCLEUS EMISSION
RADIATIONS
RARE EARTHS
RESONANCE
SAMARIUM
TARGETS