Plane containing the source, detector, incident, and specularly reflected X–ray beams in
X-ray reflectrometry.
Source:
PAC, 2020, 92, 1781. 'Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)' on page 1848 (https://doi.org/10.1515/pac-2019-0404)