JEFF-3.1 Evaluated Data: neutron data

The Joint Evaluated Fission and Fusion (JEFF) Library, version 3.1, is a general-purpose evaluated nuclear data library developed under the auspices of the OECD Nuclear Energy Agency (NEA) Data Bank. Released in 2005, JEFF-3.1 provides a consistent set of neutron-induced nuclear data for a wide range of applications, including nuclear fission and fusion reactor design, criticality safety, shielding, and fundamental research.

This library contains evaluated cross sections, resonance parameters, and related nuclear reaction data in ENDF-6 format, covering approximately 381 isotopes and elements. It incorporates experimental results and evaluation work carried out by the JEFF project and collaborating institutions, ensuring improvements in accuracy and completeness compared to previous versions.