Measurements of the fission cross section of {sup 237}Np

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:68080

Carlson, A D ^[1]; Parker, W E ^[2]; Lisowski, P W; Morgan, G L; Seestrom, S ^[3]; Hill, N W ^[4]; Meggers, K ^[5]

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1. National Institute of Standards and Technology, Gaithersburg, MD (United States)
2. Lawrence Livermore National Lab., CA (United States)
3. Los Alamos National Lab., NM (United States)
4. Oak Ridge National Lab., TN (United States)
5. Univ. of Kiel, Geesthacht (Germany)

Measurements have been made of the fission cross section of {sup 237}Np below 2 MeV neutron energy in order to improve the data base of this important cross section. The data were obtained with a white neutron source at the Los Alamos Neutron Scattering Center at Los Alamos National Laboratory. The measurements were made with ionization chambers containing {sup 237}Np deposits located at the end of a 60-m flight path. The fission cross section data are relative to the {sup 235}U(n,f) standard at the higher energies. At the lower energies, the {sup 10}B(n,{alpha}) standard was used to determine the energy dependence of the neutron fluence and the normalization was based on the very accurate 7.8 to 11.0 eV resonance integral for {sup 235}U(n,f). The results of this work indicate that the ENDF/B-VI evaluation of the {sup 237}Np(n,f) cross section is about a factor of three low in the 5 eV to 5 keV energy region but only about 3% lower than this work near 1 MeV neutron energy.

• OSTI ID: 68080
• Report Number(s): CONF-940507--Vol.1
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CROSS SECTIONS
EV RANGE 01-10
EV RANGE 10-100
EV RANGE 100-1000
FISSION
KEV RANGE 01-10
LANL
NEPTUNIUM 237
NEUTRON REACTIONS