Development and applications of multi-step Hauser-Feshbach/pre-equilibrium model theory
A recently developed model that combines compound and precompound reactions with conservation of angular momentum is discussed. This model allows a consistent description of intermediate excitations from which tertiary reaction cross sections can be calculated for transitions to the continuum as well as to the discrete residual levels with known spins and parities. Predicted neutron, proton, and alpha-particle production cross sections and emission spectra from 14-MeV neutron-induced reactions are compared favorably with angle-integrated experimental data for 12 nuclides. The model is further developed to include angular distributions of outgoing particles. The random phase approximation used for the compound stage is partially removed for the precompound stages, allowing off-diagonal terms of the collision matrix to produce both odd and even terms in the Legendre polynomial expansion for the angular distribution. Calculated double differential cross sections for the 14.6-MeV /sup 23/Na(n,n'x) reaction are compared with experimental data.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 5362376
- Report Number(s):
- CONF-800551-4; TRN: 80-012003
- Resource Relation:
- Conference: Symposium on neutron cross sections from 10 - 50 MeV, Upton, NY, USA, 12 May 1980
- Country of Publication:
- United States
- Language:
- English
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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
HAUSER-FESHBACH THEORY
NUCLEAR REACTIONS
ALPHA PARTICLES
CROSS SECTIONS
EMISSION SPECTRA
MATHEMATICAL MODELS
MEV RANGE 10-100
NEUTRON REACTIONS
BARYON REACTIONS
CHARGED PARTICLES
ENERGY RANGE
HADRON REACTIONS
MEV RANGE
NUCLEAR THEORY
NUCLEON REACTIONS
SPECTRA
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