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The EBSD detector is located within the specimen chamber of the SEM at an angle of approximately 90° to the pole piece. The EBSD detector is typically a phosphor screen that is excited by the backscattered electrons.<ref name=":45" /> The screen is coupled to lens which focuses the image from the phosphor screen onto a [[charge-coupled device]] (CCD) or c[[CMOS|omplementary metal–oxide–semiconductor]] (CMOS) camera.<ref>{{Cite journal |last1=Goulden |first1=J. |last2=Trimby |first2=P. |last3=Bewick |first3=A. |date=2018-08-01 |title=The Benefits and Applications of a CMOS-based EBSD Detector |journal=Microscopy and Microanalysis |volume=24 |issue=S1 |pages=1128–1129 |doi=10.1017/s1431927618006128 |bibcode=2018MiMic..24S1128G |s2cid=139967518 |doi-access=free }}</ref>
In this configuration, as the backscattered electrons leave the sample, they interact with the [[Electric potential|Coulomb potential]] and also lose energy due to [[inelastic scattering]] leading to a range of scattering angles (θ<sub>hkl</sub>).<ref name=":45">{{Citation |last=Randle |first=Valerie |title=Theoretical Framework for Electron Backscatter Diffraction |date=2000 |work=Electron Backscatter Diffraction in Materials Science |pages=19–30 |editor-last=Schwartz |editor-first=Adam J. |place=Boston, MA |publisher=Springer US |doi=10.1007/978-1-4757-3205-4_2 |isbn=978-1-4757-3205-4 |editor2-last=Kumar |editor2-first=Mukul |editor3-last=Adams |editor3-first=Brent L. }}</ref><ref name=":19">{{Citation |last1=Eades |first1=Alwyn |title=Energy Filtering in EBSD |date=2009 |work=Electron Backscatter Diffraction in Materials Science |pages=53–63 |editor-last=Schwartz |editor-first=Adam J. |place=Boston, MA |doi=10.1007/978-0-387-88136-2_4 |isbn=978-0-387-88136-2 |last2=Deal |first2=Andrew |last3=Bhattacharyya |first3=Abhishek |last4=Hooghan |first4=Tejpal |editor2-last=Kumar |editor2-first=Mukul |editor3-last=Adams |editor3-first=Brent L. |editor4-last=Field |editor4-first=David P. }}</ref> The backscattered electrons form [[Kikuchi lines (physics)|Kikuchi lines]] – having different intensities – on an electron-sensitive flat film/screen (commonly phosphor), gathered to form a Kikuchi band. These Kikuchi lines are the trace of a hyperbola formed by the intersection of [[Walther Kossel|Kossel]] cones with the plane of the phosphor screen. The width of a Kikuchi band is related to the scattering angles and, thus, to the distance d<sub>hkl</sub> between lattice planes with Miller indexes h, k, and l.<ref name=":20">{{Cite journal |last1=Wilkinson |first1=Angus J. |last2=Britton |first2=T. Ben. |date=2012 |title=Strains, planes, and EBSD in materials science |journal=Materials Today |volume=15 |issue=9 |pages=366–376 |doi=10.1016/S1369-7021(12)70163-3 |doi-access=free }}</ref><ref>{{Cite journal |last1=Sawatzki |first1=Simon |last2=Woodcock |first2=Thomas G. |last3=Güth |first3=Konrad |last4=Müller |first4=Karl-Hartmut |last5=Gutfleisch |first5=Oliver |date=2015 |title=Calculation of remanence and degree of texture from EBSD orientation histograms and XRD rocking curves in Nd–Fe–B sintered magnets |journal=Journal of Magnetism and Magnetic Materials |volume=382 |pages=219–224 |doi=10.1016/j.jmmm.2015.01.046 |bibcode=2015JMMM..382..219S }}</ref> These Kikuchi lines and patterns were named after [[Seishi Kikuchi]], who, together with [[Shoji Nishikawa]], was the first to notice this diffraction pattern in 1928 using [[transmission electron microscopy]] (TEM)<ref>{{Cite journal |last1=Nishikawa |first1=S. |last2=Kikuchi |first2=S. |date=June 1928 |title=Diffraction of Cathode Rays by Mica |url=http://dx.doi.org/10.1038/1211019a0 |journal=Nature |volume=121 |issue=3061 |pages=1019–1020 |doi=10.1038/1211019a0 |bibcode=1928Natur.121.1019N |issn=0028-0836|url-access=subscription }}</ref> which is similar in geometry to X-ray Kossel pattern.<ref>{{Cite journal |last1=Tixier |first1=R. |last2=Waché |first2=C. |date=1970 |title=Kossel patterns |journal=Journal of Applied Crystallography |volume=3 |issue=6 |pages=466–485 |doi=10.1107/S0021889870006726 |bibcode=1970JApCr...3..466T }}</ref><ref>{{Citation |last1=Maitland |first1=Tim |title=Backscattering Detector and EBSD in Nanomaterials Characterization |date=2007 |work=Scanning Microscopy for Nanotechnology: Techniques and Applications |pages=41–75 |editor-last=Zhou |editor-first=Weilie |place=New York, New York |publisher=Springer |doi=10.1007/978-0-387-39620-0_2 |isbn=978-0-387-39620-0 |last2=Sitzman |first2=Scott |editor2-last=Wang |editor2-first=Zhong Lin}}</ref>
The systematically arranged Kikuchi bands, which have a range of intensity along their width, intersect around the centre of the regions of interest (ROI), describing the probed volume crystallography.<ref>{{Cite journal |date=1954|title=High-angle Kikuchi patterns |journal=Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences |volume=221 |issue=1145 |pages=224–242 |doi=10.1098/rspa.1954.0017 |bibcode=1954RSPSA.221..224A |last1=Alam |first1=M. N. |last2=Blackman |first2=M. |last3=Pashley |first3=D. W. |s2cid=97131764 }}</ref> These bands and their intersections form what is known as Kikuchi patterns or electron backscatter patterns (EBSPs). To improve contrast, the patterns' background is corrected by removing anisotropic/inelastic scattering using static background correction or dynamic background correction.<ref>{{Cite journal |last1=Dingley |first1=D J |last2=Wright |first2=S I |last3=Nowell |first3=M M |date=August 2005 |title=Dynamic Background Correction of Electron Backscatter Diffraction Patterns |journal=Microscopy and Microanalysis |volume=11 |issue=S02 |doi=10.1017/S1431927605506676 |s2cid=137658758 |doi-access=free }}</ref>
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=== Pattern indexing ===
[[File:EBSP Indexing and formation.tif|thumb|Formation of Kossel cone which intersects with CCD screen to form EBSP which can be [[Bravais-Miller indices|Bravais-Miller indexed]]|alt=Formation of Kossel cone which intersect with CCD screen to form EBSP which can be Bravais-Miller indexed]]
If the setup geometry is well described, it is possible to relate the bands present in the diffraction pattern to the underlying crystal and [[Orientation (geometry)|crystallographic orientation]] of the material within the electron interaction volume. Each band can be indexed individually by the [[Miller index|Miller indices]] of the diffracting plane which formed it. In most materials, only three bands/planes intersect and are required to describe a unique solution to the crystal orientation (based on their interplanar angles). Most commercial systems use look-up tables with international crystal databases to index. This crystal orientation relates the orientation of each sampled point to a reference crystal orientation.<ref name=":18" /><ref name=":21">{{Citation |last1=El-Dasher |first1=Bassem |title=Application of Electron Backscatter Diffraction to Phase Identification |date=2009 |url=https://digital.library.unt.edu/ark:/67531/metadc1012145/ |work=Electron Backscatter Diffraction in Materials Science |pages=81–95 |editor-last=Schwartz |editor-first=Adam J. |access-date=20 March 2023 |archive-url=https://web.archive.org/web/20230325200543/https://digital.library.unt.edu/ark:/67531/metadc1012145/ |url-status=live |place=Boston, MA |publisher=Springer US |doi=10.1007/978-0-387-88136-2_6 |isbn=978-0-387-88136-2 |archive-date=25 March 2023 |last2=Deal |first2=Andrew |editor2-last=Kumar |editor2-first=Mukul |editor3-last=Adams |editor3-first=Brent L. |editor4-last=Field |editor4-first=David P.|url-access=subscription }}</ref>
Indexing is often the first step in the EBSD process after pattern collection. This allows for the identification of the crystal orientation at the single volume of the sample from where the pattern was collected.<ref>{{Cite web |title=New technique provides detailed views of metals' crystal structure |url=https://news.mit.edu/2016/metals-crystal-structure-0706 |url-status=live |archive-url=https://web.archive.org/web/20230302142459/https://news.mit.edu/2016/metals-crystal-structure-0706 |archive-date=2023-03-02 |website=MIT News {{!}} Massachusetts Institute of Technology|date=6 July 2016 }}</ref><ref name="EBSDSpringer2009">{{cite book |url=https://archive.org/details/electronbackscat00ajsc |title=Electron backscatter diffraction in materials science |date=2009 |publisher=Springer Science+Business Media |isbn=978-0-387-88135-5 |edition=2nd |page=[https://archive.org/details/electronbackscat00ajsc/page/n21 1] |url-access=limited}}</ref> With EBSD software, pattern bands are typically detected via a mathematical routine using a modified [[Hough transform]], in which every pixel in Hough space denotes a unique line/band in the EBSP. The Hough transform enables band detection, which is difficult to locate by computer in the original EBSP. Once the band locations have been detected, it is possible to relate these locations to the underlying crystal orientation, as angles between bands represent angles between lattice planes. Thus, an orientation solution can be determined when the position/angles between three bands are known. In highly symmetric materials, more than three bands are typically used to obtain and verify the orientation measurement.<ref name="EBSDSpringer2009" />
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=== Earlier trials ===
The change and degradation in electron backscatter patterns (EBSPs) provide information about the diffracting volume. Pattern degradation (i.e., diffuse quality) can be used to assess the level of plasticity through the pattern/image quality (IQ),<ref>{{Cite journal |last1=Lassen |first1=N. C. Krieger |last2=Jensen |first2=Dorte Juul |last3=Condradsen |first3=K. |date=1994 |title=Automatic Recognition of Deformed and Recrystallized Regions in Partly Recrystallized Samples Using Electron Back Scattering Patterns |url=https://www.scientific.net/MSF.157-162.149 |journal=Materials Science Forum |volume=157–162 |pages=149–158 |doi=10.4028/www.scientific.net/MSF.157-162.149 |s2cid=137129038 |access-date=2 March 2023 |archive-date=2 March 2023 |archive-url=https://web.archive.org/web/20230302135533/https://www.scientific.net/MSF.157-162.149 |url-status=live |url-access=subscription }}</ref> where IQ is calculated from the sum of the peaks detected when using the conventional Hough transform. [[Angus Wilkinson|Wilkinson]]<ref>{{Cite journal |last=Wilkinson |first=A. J. |date=1997-01-01 |title=Methods for determining elastic strains from electron backscatter diffraction and electron channelling patterns |journal=Materials Science and Technology |volume=13 |issue=1 |pages=79–84 |doi=10.1179/mst.1997.13.1.79 |bibcode=1997MatST..13...79W}}</ref> first used the changes in high-order Kikuchi line positions to determine the elastic strains, albeit with low [[Accuracy and precision|precision]]{{NoteTag|Throughout this page, the terms ‘error’, and ‘precision’ are used as defined in the [[International Bureau of Weights and Measures]] (BIPM) [https://www.bipm.org/documents/20126/2071204/JCGM_100_2008_E.pdf/cb0ef43f-baa5-11cf-3f85-4dcd86f77bd6 guide to measurement uncertainty]. In practice, ‘error’, ‘accuracy’ and ‘uncertainty’, as well as ‘true value’ and ‘best guess’, are synonymous. Precision is the variance (or standard deviation) between all estimated quantities. Bias is the difference between the average of measured values and an independently measured ‘best guess’. Accuracy is then the combination of bias and precision.<ref name=":10" />}} (0.3% to 1%); however, this approach cannot be used for characterising residual elastic strain in metals as the elastic strain at the yield point is usually around 0.2%. Measuring strain by tracking the change in the higher-order Kikuchi lines is practical when the strain is small, as the band position is sensitive to changes in lattice parameters.<ref name=":24">{{Cite journal |last1=Zhu |first1=Chaoyi |last2=De Graef |first2=Marc |date=2020 |title=EBSD pattern simulations for an interaction volume containing lattice defects |journal=Ultramicroscopy |volume=218 |pages=113088 |doi=10.1016/j.ultramic.2020.113088 |pmid=32784084 |s2cid=221123906 |doi-access=free }}</ref> In the early 1990s, Troost ''et al.''<ref>{{Cite journal |last1=Troost |first1=K. Z. |last2=van der Sluis |first2=P. |last3=Gravesteijn |first3=D. J. |date=1993 |title=Microscale elastic-strain determination by backscatter Kikuchi diffraction in the scanning electron microscope |journal=Applied Physics Letters |volume=62 |issue=10 |pages=1110–1112 |doi=10.1063/1.108758 |bibcode=1993ApPhL..62.1110T }}</ref> and Wilkinson ''et al.''<ref>{{Cite journal |last1=Wilkinson |first1=A. J. |last2=Dingley |first2=D. J. |date=1991 |title=Quantitative deformation studies using electron back scatter patterns |journal=Acta Metallurgica et Materialia |volume=39 |issue=12 |pages=3047–3055 |doi=10.1016/0956-7151(91)90037-2 }}</ref><ref>{{Cite journal |last=Wilkinson |first=Angus J. |date=1996 |title=Measurement of elastic strains and small lattice rotations using electron back scatter diffraction |journal=Ultramicroscopy |volume=62 |issue=4 |pages=237–247 |doi=10.1016/0304-3991(95)00152-2 |pmid=22666906 }}</ref> used pattern degradation and change in the zone axis position to measure the residual elastic strains and small lattice rotations with a 0.02% precision.<ref name=":10" />
=== High-resolution electron backscatter diffraction (HR-EBSD)===
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* {{Cite journal |last1=Britton |first1=T. Ben |author-link=Ben Britton |last2=Jiang |first2=Jun |last3=Guo |first3=Y. |last4=Vilalta-Clemente |first4=A. |last5=Wallis |first5=D. |last6=Hansen |first6=L.N. |last7=Winkelmann |first7=A. |last8=Wilkinson |first8=A.J. |author-link8=Angus Wilkinson |date=July 2016 |title=Tutorial: Crystal orientations and EBSD — Or which way is up? |journal=Materials Characterization |volume=117 |pages=113–126 |doi=10.1016/j.matchar.2016.04.008 |s2cid=138070296|ref=none|doi-access=free |hdl=10044/1/31250 |hdl-access=free }}
* {{Cite journal |last1=Charpagne |first1=Marie-Agathe |last2=Strub |first2=Florian |last3=Pollock |first3=Tresa M. |author-link3=Tresa Pollock |date=April 2019 |title=Accurate reconstruction of EBSD datasets by a multimodal data approach using an evolutionary algorithm |journal=Materials Characterization |volume=150 |pages=184–198 |doi=10.1016/j.matchar.2019.01.033|arxiv=1903.02988 |s2cid=71144677 |ref=none}}
* {{Cite journal |last1=Jackson |first1=M. A. |last2=Pascal |first2=E. |last3=De Graef |first3=M. |date=2019 |title=Dictionary Indexing of Electron Back-Scatter Diffraction Patterns: a Hands-On Tutorial |url=https://link.springer.com/article/10.1007/s40192-019-00137-4 |journal=Integrating Materials and Manufacturing Innovation |volume=8 |issue=2 |pages=226–246 |doi=10.1007/s40192-019-00137-4|s2cid=182073071 |ref=none|url-access=subscription }}
* {{Cite journal |last=Randle |first=Valerie |author-link=Valerie Randle |date=September 2009 |title=Electron backscatter diffraction: Strategies for reliable data acquisition and processing |journal=Materials Characterization |volume=60 |issue=90 |pages=913–922 |doi=10.1016/j.matchar.2009.05.011|ref=none}}
* {{Cite book |title=Electron Backscatter Diffraction in Materials Science |editor-first1=Adam J. |editor-first2=Mukul |editor-first3=Brent L. |editor-first4=David P. |editor-last1=Schwartz |editor-last2=Kumar |editor-last3=Adams |editor-last4=Field |year=2009 |publisher=Springer New York, New York |isbn=978-0-387-88135-5 |edition=2nd |___location=New York, New York |publication-date=12 August 2009 |doi=10.1007/978-0-387-88136-2|ref=none}}
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