Measurements of absolute delayed neutron yield and group constants in the fast fission of {sup 235}U and {sup 237}Np

Journal Article · Sun Mar 01 00:00:00 EST 1998 · Nuclear Science and Engineering

OSTI ID:616136

Loaiza, D J; Brunson, G; Sanchez, R; Butterfield, K ^[1]

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1. Los Alamos National Lab., NM (United States)

The delayed neutron activity resulting from the fast induced fission of {sup 235}U and {sup 237}Np has been studied. The six-group decay constants, relative abundances, and absolute yield of delayed neutrons from fast fission of {sup 235}U and {sup 237}Np were measured using the Godiva IV fast assembly at the Los Alamos Critical Experiments Facility. The absolute yield measured for {sup 235}U was 0.0163 {+-} 0.0008 neutron/fission. This value compares very well with the well-established Keepin absolute yield of 0.0165 {+-} 0.0005. The absolute yield value measured for {sup 237}Np was 0.0126 {+-} 0.0007. The measured delayed neutron parameters for {sup 235}U are corroborated with period (e-folding time) versus reactivity calculations.

• OSTI ID: 616136
• Journal Information: Nuclear Science and Engineering, Vol. 128, Issue 3; Other Information: PBD: Mar 1998
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
URANIUM 235 TARGET
NEPTUNIUM 237 TARGET
FAST FISSION
DELAYED NEUTRONS
FISSION YIELD
GROUP CONSTANTS