ENDF/B-VIII.1: Neutron Reaction Sublibrary

The neutrons sublibrary aims to describe nuclear reactions between incident neutron particles and different nuclei. For ENDF/B-VIII.1, many neutron files were re-evaluated or received major changes. A new 239Pu evaluation was jointly-produced by IAEA, LANL, LLNL and ORNL bringing important updates to fission neutron multiplicity, Prompt Fission Neutron Spectrum, resonance and fast regions. Around one third of the new neutron evaluations were performed as part of the INDEN collaboration, including ^16,18O, ¹⁹F, ^28,29,30Si, ^63,65Cu, ^{50,51,52,53,54}Cr, ⁵⁵Mn, ^54,56,57Fe, ¹³⁹La, ^233,235,238U, ^240,241Pu. Important non-INDEN evaluations include ^234,236U, ^206,207,208Pb, ¹⁸¹Ta, ⁸⁸Sr, ^140,142Ce, Pt and Dy isotopes, and many others. Also, dosimetry reactions from IRDFF-II were adopted for many materials.