Editing Wide-angle X-ray scattering (section)

{{Short description|Technique in X-ray crystallography}}
{{Refimprove|date=December 2011}}
In [[X-ray crystallography]], '''wide-angle X-ray scattering''' ('''WAXS''') or '''wide-angle X-ray diffraction''' ('''WAXD''') is the analysis of [[Bragg peak]]s scattered to wide angles, which (by [[Bragg's law]]) are caused by sub-nanometer-sized structures.<ref>{{cite journal | last=Podorov | first=S. G. | last2=Faleev | first2=N. N. | last3=Pavlov | first3=K. M. | last4=Paganin | first4=D. M. | last5=Stepanov | first5=S. A. | last6=Förster | first6=E. | title=A new approach to wide-angle dynamical X-ray diffraction by deformed crystals | journal=Journal of Applied Crystallography | publisher=International Union of Crystallography (IUCr) | volume=39 | issue=5 | date=2006-09-12 | issn=0021-8898 | doi=10.1107/s0021889806025696 | pages=652–655}}</ref> It is an [[X-ray diffraction|X-ray-diffraction]]<ref>"WIDE-ANGLE X-RAY DIFFRACTION THEORY VERSUS CLASSICAL DYNAMICAL THEORY" by S.G. Podorov, A. Nazarkin, Recent Res. Devel. Optics, 7 (2009) {{ISBN|978-81-308-0370-8}}</ref> method and commonly used to determine a range of information about crystalline materials. The term WAXS is commonly used in [[polymer]] sciences to differentiate it from SAXS but many scientists doing "WAXS" would describe the measurements as Bragg/X-ray/powder diffraction or [[crystallography]]. 

Wide-angle X-ray scattering is similar to [[small-angle X-ray scattering]] (SAXS) but the increasing angle between the sample and detector is probing smaller length scales. This requires samples to be more ordered/crystalline for information to be extracted. In a dedicated SAXS instrument the distance from sample to the detector is longer to increase angular resolution. Most diffractometers can be used to perform both WAXS and limited SAXS in a single run (small- and wide-angle scattering, SWAXS) by adding a beamstop/knife edge.