Editing Synchrotron light source (section)

===Diffraction and scattering===
[[X-ray diffraction]] (XRD) and [[scattering]] experiments are performed at synchrotrons for the structural analysis of [[crystalline]] and [[amorphous]] materials. These measurements may be performed on [[Powder diffraction|powders]], [[single crystals]], or [[thin films]]. The high resolution and intensity of the synchrotron beam enables the measurement of scattering from dilute phases or the analysis of [[residual stress]]. Materials can be studied at [[high pressure]] using [[diamond anvil cell]]s to simulate extreme geologic environments or to create exotic forms of matter.{{Citation needed|date=January 2021}}
[[Image:010 large subunit-1FFK.gif|thumb|200px|left| Structure of a [[ribosome]] subunit solved at high resolution using synchrotron X-ray crystallography.<ref name=Ban2000>{{cite journal | last1=Ban | first1=N. |first2=P. |last2=Nissen|first3=J. |last3=Hansen |first4=P. |last4=Moore|first5= T. |last5=Steitz |title=The Complete Atomic Structure of the Large Ribosomal Subunit at 2.4 Å Resolution | journal=Science | volume=289 | issue=5481 | date=2000-08-11 | doi=10.1126/science.289.5481.905 | pmid=10937989 | pages=905–920| bibcode=2000Sci...289..905B }}</ref>]]

[[X-ray crystallography]] of [[proteins]] and other macromolecules (PX or MX) are routinely performed. Synchrotron-based crystallography experiments were integral to solving the structure of the [[ribosome]];<ref name=Ban2000 /><ref>The Royal Swedish Academy of Sciences, [https://www.nobelprize.org/nobel_prizes/chemistry/laureates/2009/popular-chemistryprize2009.pdf "The Nobel Prize in Chemistry 2009: Information for the Public"], accessed 2016-06-20</ref> this work earned the [https://www.nobelprize.org/nobel_prizes/chemistry/laureates/2009/ Nobel Prize in Chemistry in 2009].

The size and shape of [[nanoparticles]] are characterized using [[small angle X-ray scattering]] (SAXS). Nano-sized features on surfaces are measured with a similar technique, [[Grazing-incidence small-angle scattering|grazing-incidence small angle X-ray scattering]] (GISAXS).<ref>{{cite journal | last1=Renaud | first1=Gilles | last2=Lazzari | first2=Rémi | last3=Leroy | first3=Frédéric | title=Probing surface and interface morphology with Grazing Incidence Small Angle X-Ray Scattering | journal=Surface Science Reports | volume=64 | issue=8 | year=2009 | doi=10.1016/j.surfrep.2009.07.002 | pages=255–380| bibcode=2009SurSR..64..255R }}</ref> In this and other methods, surface sensitivity is achieved by placing the crystal surface at a small angle relative to the incident beam, which achieves [[total external reflection]] and minimizes the X-ray penetration into the material.{{Citation needed|date=January 2021}}

The atomic- to nano-scale details of [[Surface science|surfaces]], interfaces, and [[thin films]] can be characterized using techniques such as [[X-ray reflectivity]] (XRR) and [[X-ray crystal truncation rod|crystal truncation rod]] (CTR) analysis.<ref>{{cite journal | last1=Robinson | first1=I K | last2=Tweet | first2=D J | title=Surface X-ray diffraction | journal=Reports on Progress in Physics | volume=55 | issue=5 | date=1992-05-01 | doi=10.1088/0034-4885/55/5/002 | pages=599–651| bibcode=1992RPPh...55..599R | s2cid=250899816 }}</ref> [[X-ray standing wave]] (XSW) measurements can also be used to measure the position of atoms at or near surfaces; these measurements require high-resolution optics capable of resolving [[dynamical diffraction]] phenomena.<ref>{{cite journal | last1=Golovchenko | first1=J. A. | last2=Patel | first2=J. R. | last3=Kaplan | first3=D. R. | last4=Cowan | first4=P. L. |author5-link=Michael Bedzyk | last5=Bedzyk | first5=M. J. | title=Solution to the Surface Registration Problem Using X-Ray Standing Waves | journal=Physical Review Letters | volume=49 | issue=8 | date=1982-08-23 | doi=10.1103/physrevlett.49.560 | pages=560–563| bibcode=1982PhRvL..49..560G | url=https://dash.harvard.edu/bitstream/1/29407052/1/SolutionToTheSurfaceRegistrationProblem.pdf }}</ref>

Amorphous materials, including liquids and melts, as well as crystalline materials with local disorder, can be examined using X-ray [[pair distribution function]] analysis, which requires high energy X-ray scattering data.<ref>T. Egami, S.J.L. Billinge, "Underneath the Bragg Peaks: Structural Analysis of Complex Materials", [https://books.google.com/books?id=ek2ymu7_NfgC&pg=PP2 ''Pergamon'' (2003)]</ref>

By tuning the beam energy through the [[absorption edge]] of a particular element of interest, the scattering from atoms of that element will be modified. These so-called resonant anomalous X-ray scattering methods can help to resolve scattering contributions from specific elements in the sample.{{Citation needed|date=January 2021}}

Other scattering techniques include [[EDXRD|energy dispersive X-ray diffraction]], [[resonant inelastic X-ray scattering]], and magnetic scattering.{{Citation needed|date=January 2021}}