/sup 238/U issues resolved and unresolved
The interaction of 1 eV to 20 MeV neutrons with /sup 238/U is discussed with emphasis on recently resolved and remaining issues relevant to both application need and physical understanding. The apparent inability of older /sup 238/U evaluations to predict the measured /sup 238/U capture rate in thermal critical lattices has stimulated several recent precise measurements of the /sup 238/U cross sections, reanalysis of older data, and improved evaluations. The recent evaluations predict satisfactorily the /sup 238/U capture rate in thermal critical lattices. In the region from 1.5 to 4 keV there are differences of the order of 15%, sometimes larger, between the values of the neutron widths of the main resonances reported by several experimenters or obtained by different evaluators. Above 4 keV there are only sparse results of resonance analysis and most evaluations adopt a statistical treatment of the resonance structure. Some factors affecting the determination of the average properties of the resonance parameters are discussed. Above the inelastic-scattering threshold, energy-averaged neutron total, scattering, capture and fission cross sections are reviewed in a unified manner integrating measurement, calculation and evaluation. (n;n') and (n;2n') energy-transfer mechanisms are addressed. Particular attention is given to neutron capture, stressing precisions consistent with applied need. Fission properties are discussed including: prompt and delayed fission-neutron spectra and nubar, and fission-product yields. Physical understanding is assayed, with attention to compound-nucleus and direct-reaction mechanisms, and applications impact is illustrated in the context of fast-breeder-reactor performance. 95 references.
- Research Organization:
- Oak Ridge National Lab., TN (USA); Argonne National Lab., IL (USA)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 7094751
- Report Number(s):
- CONF-820942-17; ON: DE82022329; TRN: 82-025694
- Resource Relation:
- Conference: Nuclear data for science and technology international conference, Antwerp, Belgium, 6 Sep 1982; Other Information: Portions of document are illegible
- Country of Publication:
- United States
- Language:
- English
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NEUTRON REACTIONS
CAPTURE
CROSS SECTIONS
FISSION
URANIUM 238 TARGET
COMPOUND-NUCLEUS REACTIONS
DELAYED NEUTRONS
DIRECT REACTIONS
ELASTIC SCATTERING
EV RANGE
FISSION PRODUCTS
FISSION YIELD
INELASTIC SCATTERING
KEV RANGE
LEVEL WIDTHS
MEV RANGE 01-10
MEV RANGE 10-100
REACTOR PHYSICS
RESONANCE
REVIEWS
SELF-SHIELDING
TOTAL CROSS SECTIONS
BARYON REACTIONS
BARYONS
DOCUMENT TYPES
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
FISSION NEUTRONS
HADRON REACTIONS
HADRONS
ISOTOPES
MATERIALS
MEV RANGE
NEUTRONS
NUCLEAR REACTION YIELD
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUCLEONS
PHYSICS
RADIOACTIVE MATERIALS
SCATTERING
SHIELDING
TARGETS
YIELDS
220100* - Nuclear Reactor Technology- Theory & Calculation