Evaluation of ²³²Th and ²³⁷Np fast neutron-induced fission cross sections by simultaneous evaluation approach

¹ Department of Physics, Panjab University, Chandigarh -160014, India
² Nuclear Data Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, A-1400 Wien, Austria
³ University Institute of Engineering and Technology, Panjab University, Chandigarh -160014, India

^* e-mail: vidyathakur@yahoo.co.in

Published online: 14 March 2025

Abstract

The neutron-induced fission cross sections for ²³²Th and ²³⁷Np were evaluated from 500 keV to 200 MeV and from 70 keV to 200 MeV, respectively. The experimental fission cross sections for ²³²Th and ²³⁷Np, as well as their ratios to the ^235,238U, and ²³⁹Pu fission cross section in the EXFOR library, were reviewed and analyzed using the least-squares method. The newly published ²³²Th/²³⁷Np fission cross-section ratios, obtained from the time-of-flight measurements at the CERN n_TOF and CSNS Back-n facilities, have been added to the EXFOR database. The new evaluation shows that the ²³²Th fission cross section is systematically lower than that provided by the JENDL-5 library.