Fission cross section ratios in the /sup 252/Cf neutron spectrum (/sup 235/U: /sup 238/U /sup 239/Pu: /sup 237/Np)

Conference · Wed Oct 01 00:00:00 EDT 1975 · Natl. Bur. Stand. (U.S.), Spec. Publ.; (United States)

OSTI ID:7285349

Gilliam, D M; Eisenhauer, C; Heaton, II, H T; Grundl, J A

In a /sup 252/Cf neutron field, ratios of spectrum-averaged fission cross sections have been measured by back-to-back counting in a double fission ionization chamber with interchangeable deposits of /sup 235/U, /sup 238/U, /sup 239/Pu, and /sup 237/Np. These ratio measurements provide integral tests for evaluated cross section data. The dominant error in the ratio measurements was the +-1.4 percent to +-2.1 percent uncertainty in the fissionable deposit masses. Redundant mass assay methods were employed for all deposit nuclides. Corrections of up to (1.4 +- 0.7) percent were necessary for inelastic scattering effects on the neutron energy distribution in the cases of /sup 238/U and /sup 237/Np. For /sup 235/U and /sup 239/Pu fission rates, a correction of (0.45 + 0.20) percent was made for the contribution of neutrons moderated and back-scattered by laboratory structures. The cross section ratios observed in the present measurements were as follows: 1.000: 0.266 +- 1.7 percent: 1.500 +- 1.6 percent: 1.105 +- 2.2 percent for /sup 235/U: /sup 238/U: /sup 239/Pu: /sup 237/Np, respectively. In comparison to the observed integral cross section ratios, the corresponding values derived from ENDF/B-IV data were 2.3 percent to 6.0 percent lower. 4 tables, 1 figure. (auth)

• Research Organization: National Bureau of Standards, Washington, DC
• OSTI ID: 7285349
• Journal Information: Natl. Bur. Stand. (U.S.), Spec. Publ.; (United States), Vol. 1; Conference: Proceedings on nuclear cross section and technology, Washington, DC, USA, 3 Mar 1975; Other Information: See NBS-SPEC.PUBL.--425(Vol. 1); CONF-750303--P1
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
NEUTRON REACTIONS
FISSION
URANIUM 235 TARGET
URANIUM 238 TARGET
PLUTONIUM 239 TARGET
NEPTUNIUM 237 TARGET
FISSION NEUTRONS
CROSS SECTIONS
CALIFORNIUM 252
NEUTRON SOURCES
SPONTANEOUS FISSION
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
BARYON REACTIONS
BARYONS
CALIFORNIUM ISOTOPES
ELEMENTARY PARTICLES
EVEN-EVEN NUCLEI
FERMIONS
HADRON REACTIONS
HADRONS
HEAVY NUCLEI
ISOTOPES
NEUTRONS
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
NUCLEONS
PARTICLE SOURCES
RADIATION SOURCES
RADIOISOTOPES
TARGETS
YEARS LIVING RADIOISOTOPES
652026* - Nuclear Properties & Reactions
A=220 & above
Experimental- Spontaneous & Induced Fission- (-1987)