Measurements of thermal neutron cross section and resonance integral for the {sup 237}Np(n,{gamma}){sup 238}Np reaction

Book · Sat Dec 31 04:00:00 EST 1994

OSTI ID:55634

Kobayashi, Katsuhei ^[1]; Yamanaka, Akihiro ^[2]; Kimura, Itsuro ^[3]

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1. Kyoto Univ., Osaka (Japan)
2. Hitachi Ltd., Ibaraki (Japan). Hitachi Works
3. Kyoto Univ. (Japan). Dept. of Nuclear Engineering

Making use of a standard neutron spectrum field with a pure Maxwellian distribution at the heavy water thermal neutron facility of the Kyoto University Reactor (KUR), the thermal neutron cross section for the {sup 237}Np(n,{gamma}){sup 238}Np reaction was measured by the activation method, using a high purity Ge detector. The result is 158 {+-} 3 b, which is obtained relative to the reference value of 98.65 {+-} 0.09 b for the {sup 197}Au(n,{gamma}){sup 198}Au reaction. The present value is lower by about 13% than that of the ENDF/B-VI data. The data given by Mughabghab and obtained from JENDL-3 are larger by 11 to 14% than the present measurement. The resonance integral for the {sup 237}Np(n,{gamma}){sup 238}Np reaction was measured with a 1/E standard neutron spectrum in the cavity of the central graphite reflector region between the two-divided cores of the Kinki University Reactor (UTR-KINK), relative to the reference value of 1,550 {+-} 28 b for the {sup 197}Au(n,{gamma}){sup 198}Au reaction. By defining the Cd cut-off energy as 0.5 eV, the present resonance integral is 652 {+-} 24 b, which is in good agreement with the JENDL-3, ENDF/B-VI and Mughabghab data. However, most of the old experimental data are, in general, larger by 24 to 38% than the present measurement.

• OSTI ID: 55634
• Report Number(s): CONF-930809--; ISBN 0-8031-1899-6
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CAPTURE
COMPARATIVE EVALUATIONS
EXPERIMENTAL DATA
GE SEMICONDUCTOR DETECTORS
NEPTUNIUM 237 TARGET
NESDPS Office of Nuclear Energy Space and Defense Power Systems
NEUTRON REACTIONS
NUCLEAR DATA COLLECTIONS
RESONANCE INTEGRALS
USES