{"term":{"id":"09221","title":"angle of emission","longtitle":"IUPAC Gold Book - angle of emission","doi":"10.1351\/goldbook.09221","code":"09221","status":"current","synonym":"<em>synonym<\/em>: emission angle","definitions":[{"id":1,"text":"Angle between the trajectory of a particle or photon, as it leaves a surface, and the local or average surface normal.","notes":{"1":"The particular surface normal needs to be specified.","2":"In XPS and other techniques, the take-off angle, which is referred to the sample surface, is quoted."},"links":[{"term":"take-off angle","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/09296"}],"sources":["PAC, 2020, 92, 1781. 'Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)' on page 1797 (https:\/\/doi.org\/10.1515\/pac-2019-0404)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/09221\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/09221\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/09221\/plain"},"citation":"Citation: 'angle of emission' 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.09221","license":"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.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","disclaimer":"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.","accessed":"2026-04-21T03:55:27+00:00"}}