Consistent nuclear model for compound and precompound reactions with conservation of angular momentum. [14. 6 MeV]
The exciton model of precompound reactions is modified such that it automatically reduces to the usual evaporation formula after equilibrium has been reached. The result is further modified to conserve angular momentum in a form compatible with the Hauser-Feshbach formula. Such modification allows a consistent description of intermediate excitations from which tertiary reaction cross sections can be calculated for transitions to discrete residual levels with known spins and parities. Level densities used for the compound component of reaction cross sections are derived from direct summation of the particle-hole state densities used for the precompound component. Predicted neutron, proton, and alpha-particle production cross sections and spectra from 14-MeV neutron-induced reactions are compared with experimental data. Model parameters of general validity are fixed beforehand. Two parameters are determined from calculations for /sup 56/Fe and then used with reasonable success for predicting cross sections for twelve other nuclides. 17 figures.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 5407808
- Report Number(s):
- ORNL/TM-7042
- Country of Publication:
- United States
- Language:
- English
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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA PARTICLES
ALPHA SPECTRA
ALUMINIUM 27 TARGET
ANGULAR MOMENTUM
BARYON REACTIONS
BARYONS
CHARGED PARTICLES
CHROMIUM
CHROMIUM 50 TARGET
CHROMIUM 52 TARGET
COMPOUND-NUCLEUS REACTIONS
COPPER
COPPER 63 TARGET
COPPER 65 TARGET
CROSS SECTIONS
DATA
DATA FORMS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY RANGE
EXCITON MODEL
FAST NEUTRONS
FERMIONS
GRAPHS
HADRON REACTIONS
HADRONS
HAUSER-FESHBACH THEORY
INFORMATION
INTERMEDIATE MASS NUCLEI
IRON
IRON 54 TARGET
IRON 56 TARGET
LIGHT NUCLEI
MATHEMATICAL MODELS
METALS
MEV RANGE
MEV RANGE 10-100
NEUTRON REACTIONS
NEUTRON SPECTRA
NEUTRONS
NICKEL
NICKEL 58 TARGET
NICKEL 60 TARGET
NIOBIUM 93 TARGET
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEAR THEORY
NUCLEI
NUCLEON REACTIONS
NUCLEONS
NUMERICAL DATA
PRECOMPOUND-NUCLEUS EMISSION
PROTON SPECTRA
PROTONS
SPECTRA
TARGETS
THEORETICAL DATA
TITANIUM
TITANIUM 46 TARGET
TITANIUM 48 TARGET
TRANSITION ELEMENTS
VANADIUM 51 TARGET