EXFOR-based simultaneous evaluation of neutron-induced uranium and plutonium fission cross sections for JENDL-5

Otsuka, Naohiko*; Iwamoto, Osamu  

The neutron-induced fission cross sections were simultaneously evaluated for U andPu from 10 keV to 200 MeV and for U and Pu from 100 keV to 200 MeV. Evaluation was performed by least-squares fitting of Schmittroth's roof function to the logarithms of the experimental cross sections and cross section ratios in the EXFOR library. A simultaneous evaluation code SOK was used with its extension to data in arbitrary unit. The outputs of the code were adopted as the evaluated cross sections without any further corrections. The newly obtained evaluated cross sections were compared with the evaluated cross sections in theJENDL-4.0 library. The evaluated cross sections were also validated against the californium-252 fission neutron spectrum averaged and neutron spectrum averaged cross sections.