Pre-equilibrium particle decay in the photonuclear reactions. [Exciton and quasi-deuteron models]

Technical Report · Mon Nov 01 04:00:00 EST 1976

DOI:https://doi.org/10.2172/7120139· OSTI ID:7120139

Wu, J. R.; Chang, C. C.

Calculations of particle energy spectra resulting from the photonuclear reactions at energies below the meson production threshold have been carried out in the framework of combining the pre-equilibrium exiton model and the quasi-deuteron model. A 2p-2h initial state in the exciton model is assumed because in the energy region above giant resonance the quasi-deuteron absorption is the dominant process. With these combined models, the subsequent secondary interactions of the emerging particle with the rest of the nucleus following the initial photon-nucleus interaction are appropriately taken into account. The experimental difference energy spectra of fast photoneutrons from several elements (Al, Cu, In, Sn, Ta, Pb, Bi and U) at bremsstrahlung energies of 55 and 85 MeV and the photoproton energy spectra from /sup 12/C at bremsstrahlung energy 110 MeV were compared with the theoretical predictions. General agreements in both spectral shapes and cross sections are obtained. The relative yields of the reactions (..gamma.., xn) resulting from monoenergetic photons on /sup 127/I at 50, 100 and 150 MeV are also predicted reasonably well by the combined models together with the conventional evaporation theory.

• Research Organization: University of Maryland, College Park, MD
• Sponsoring Organization: US Energy Research and Development Administration (ERDA)
• OSTI ID: 7120139
• Report Number(s): ORO-5128-4
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALUMINIUM 27 TARGET
BARYONS
BASIC INTERACTIONS
BISMUTH 209 TARGET
BREMSSTRAHLUNG
COPPER 63 TARGET
CROSS SECTIONS
ELECTROMAGNETIC INTERACTIONS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENERGY SPECTRA
FERMIONS
HADRONS
INDIUM 115 TARGET
INTERACTIONS
LEAD 207 TARGET
NEUTRONS
NUCLEAR REACTIONS
NUCLEONS
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PHOTONEUTRONS
PHOTONUCLEAR REACTIONS
PHOTONUCLEONS
PHOTOPRODUCTION
PRECOMPOUND-NUCLEUS EMISSION
RADIATIONS
SPECTRA
TANTALUM 181 TARGET
TARGETS
TIN 118 TARGET
URANIUM 235 TARGET