08742 IUPAC Gold Book - neutron energy 10.1351/goldbook.08742 08742 current 1 Kinetic energy of a free neutron. Neutron energy is usually given with unit electronvolt (\(\pu{eV}\)). \(\pu{1 eV} = \pu{1.602176634E-19 J}\). Neutron temperature has unit kelvin, and the term should not be used for the neutron energy. Neutrons are classified according to their energies as follows: PAC, 2021, 93, 69. 'Vocabulary of radioanalytical methods (IUPAC Recommendations 2020)' on page 88 (https://doi.org/10.1515/pac-2019-0302) https://goldbook.iupac.org/terms/view/08742/html https://goldbook.iupac.org/terms/view/08742/json https://goldbook.iupac.org/terms/view/08742/plain Citation: 'neutron energy' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.08742 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-05-18T03:41:21+00:00