THE SLOW-NEUTRON RESONANCE BEHAVIOUR OF PLUTONIUM ISOTOPES

Journal Article · Thu May 01 04:00:00 EDT 1958 · J. Nuclear Energy

DOI:https://doi.org/10.1016/0891-3919(58)90058-5· OSTI ID:4337779

Egelstaff, P A; Gayther, D B; Nicholson, K P

S>The neutron total cross-sections of several plutonium samples were measured from 0.02 ev to 51 kev, using the Harwell fast chopper. The samples contained various abundances of Pu/sup 230/, Pu/sup 240/, Pu/sup 241/, and Pu/sup 242/, making it possible in most cases to assign an observed resonance level to its particular isotope. The maximum resolution of the spectrometer was 0.11 mu sec/m, and at energies below about 40 ev resonance parameters were obtained for the identified levels using the area method of analysis. iThe distributions of neutron widths and level spacings in Pu/sup 239/ are compared with theoretical predictions. A value of (1.3 plus or minus 0.2) x 10/sup -4/ for the ratio of average reduced neutron width to average level spacing, GAMMA /sup o/nD, is deduced from the observed average cross-section of Pu/sup 239/ above 500 ev. The value of GAMMA /sup o//nD obtained from the separate parameters meas ured at low energies is (1.0 plus or minus 0.2) x 10/sup -4/. The fluctuations in the observed cross-section are analyzed in terms of theoretical distributions in neutron widths and level spacings. (auth)

• Research Organization: Atomic Energy Research Establishment, Harwell, Berks, Eng.
• NSA Number: NSA-12-011779
• OSTI ID: 4337779
• Journal Information: J. Nuclear Energy, Journal Name: J. Nuclear Energy Vol. Vol: 6
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CHOPPERS
CROSS SECTIONS
DISTRIBUTION
ENERGY LEVELS
ENERGY RANGE
ENRICHMENT
EV RANGE
KEV RANGE
LIFETIME
MEASURED VALUES
NEUTRON SPECTROMETERS
NEUTRONS
NUCLEAR THEORY
PHYSICS
PLUTONIUM 239
PLUTONIUM 240
PLUTONIUM 241
PLUTONIUM 242
PLUTONIUM ISOTOPES
PULSE GENERATORS
RESOLUTION
RESONANCE
STANDARDS
THERMAL NEUTRONS
VARIATIONS
VELOCITY
WIDTH