specular X-ray reflectrometry

https://doi.org/10.1351/goldbook.09204
Mode of X-ray reflectrometry in which the angle between the detected beam and the sample surface is equal to that of the incident beam and the sample surface.
Notes:
  1. Specular XRR is the plainary mode for XRR and is often meant when the term XRR is used.
  2. In this case, the angle scattering \(2 \theta\) is twice the incidence angle, \(\omega\). The detected, scattered X-ray intensity is measured as a function of either \(\omega\) or \(2 \theta\) or the scattering vector, \(q_{\rm{z}}\). The intensity data are usually presented as a function of \(q_{\rm{z}}\) or \(\omega\).
See also: off-specular X-ray reflectrometry
Source:
PAC, 2020, 92, 1781. 'Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)' on page 1792 (https://doi.org/10.1515/pac-2019-0404)