12555 IUPAC Gold Book - resonance-enhanced multiphoton ionization 10.1351/goldbook.12555 12555 current acronym: REMPI synonym: resonance ionization 1 Multiphoton ionization in which the ionization cross section is significantly enhanced because the energy of the incident photons is resonant with an intermediate excited state of the neutral. PAC, 2013, 85, 1515. 'Definitions of terms relating to mass spectrometry (IUPAC Recommendations 2013)' on page 1586 (https://doi.org/10.1351/PAC-REC-06-04-06) https://goldbook.iupac.org/terms/view/12555/html https://goldbook.iupac.org/terms/view/12555/json https://goldbook.iupac.org/terms/view/12555/plain Citation: 'resonance-enhanced multiphoton ionization' 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.12555 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. 2026-05-08T02:06:30+00:00