²⁰⁹Bi(n,f) and ^natPb(n,f) Cross Sections as a New Reference and Extension of the ²³⁵U, ²³⁸U and ²³⁹Pu(n,f) Standards up to 1 GeV

The 209Bi(n,f) and natPb(n,f) reaction cross sections are used as a reference for neutron energies above 30 MeV in the accelerator driven system applications. This report describes the update of the evaluation for 209Bi(n,f) reaction released by the IAEA in 1997 and the new evaluation for natPb(n,f). Additionally, the evaluation of the neutron fission standard cross sections of 238U, 235U and 239Pu were extended above 200 MeV up to 1 GeV. This report summarizes the results of the collection and analysis of available experimental data, CEM and Talys theoretical model calculations, and the evaluation of experimental data by the GMAP code. The final evaluated data for the 238U, 235U, 239Pu, natPb, 209Bi neutron induced fission cross sections are presented in both tabular and parameterization form. These evaluations are presented in the ENDF and text formats as well as NJOY plots and can be downloaded from the IAEA Neutron Reaction Standards web page (www-nds.iaea.org/standards/)