parity assignment of the pronounced structure in the radiative capture of neutrons by /sup 238/U below 100 keV
Some years ago, Perez and de Saussure reported evidence for intermediate structure in the radiative capture cross sections of /sup 238/U. More recently, these and additional data, obtained by a different experimental technique but which showed the same non-statistical behavior, were analyzed by Perez et al. Under the assumption that the structure could be attributed to doorway states in the p/sup 3/2/ neutron channel. The results of an experimental determination of the parity of the structure, using neutron capture-gamma ray spectroscopy are reported. Much of the structure below 50 keV appears to be due to s-wave interactions. The magnitude of the fluctuations is much larger than can be calculated with the usual unresolved - resonance treatment unless the average neutron and radiative-capture widths are correlated. It is shown that such an apparent correlation can arise as a result of multiple-scattering enhancement of radiative capture in the samples used, and it is concluded that the evidence for intermediate structure in the capture of neutrons by /sup 238/U is not yet firmly established.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 5927566
- Report Number(s):
- LA-UR-81-2649; CONF-810957-3; ON: DE82000592; TRN: 82-001271
- Resource Relation:
- Conference: Joint IAEA/NEA consultants meeting on uranium and plutonium resonance parameters, Vienna, Austria, 28 Sep 1981
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
NEUTRON REACTIONS
CAPTURE
URANIUM 238 TARGET
CROSS SECTIONS
ENERGY DEPENDENCE
FLUCTUATIONS
INTERMEDIATE STRUCTURE
KEV RANGE 10-100
P WAVES
PARITY
RESONANCE
S WAVES
TOTAL CROSS SECTIONS
BARYON REACTIONS
ENERGY RANGE
HADRON REACTIONS
KEV RANGE
NUCLEAR REACTIONS
NUCLEON REACTIONS
PARTIAL WAVES
PARTICLE PROPERTIES
TARGETS
VARIATIONS
652025* - Nuclear Properties & Reactions
A=220 & above
Experimental- Nuclear Reactions & Scattering- (-1987)