Resonant scattering - Revision history

BrianMcMahon: Added German translation (U. Mueller)

2017-11-17T17:01:14Z

Added German translation (U. Mueller)

BrianMcMahon at 16:33, 16 May 2017

2017-05-16T16:33:50Z

MassimoNespolo: /* History */ see laso

2015-03-04T05:39:39Z

‎History: see laso

MassimoNespolo: Lang

2015-03-04T05:35:31Z

Lang

HowardFlack: /* Definition */

2013-10-11T15:29:58Z

‎Definition

HowardFlack: Created page with "== Definition == The elementary theory of the scattering of X-rays by atoms, leading to the real atomic scattering factor $f_o$ , applies only for X-radiation whose wa..."

2013-10-11T15:17:46Z

Created page with "== Definition == The elementary theory of the scattering of X-rays by atoms, leading to the real atomic scattering factor <math>f_o</math>, applies only for X-radiation whose wa..."

New page

== Definition ==

The elementary theory of the scattering of X-rays by atoms, leading to the real atomic scattering factor <math>f_o</math>, applies only for X-radiation whose wavelength is far removed from that of any natural (resonant) frequency of the atom. When this condition does not hold, one needs to use as physical model for the scattering that of a forced damped harmonic oscillator. This leads to resonant-scattering terms in the full, now complex, scattering factor of an atom, represented by:-

<math>f=f_o + f\,' + if\,''</math> .

The real and imaginary terms, <math> f\,', f\,''</math>, in the atomic scattering factor are independent of sinq/l and in general small compared to <math>f_o</math>.
The values of <math>f\,'</math> and <math>f\,''</math> change most at the absorption edge of the element in question.

In the older literature the term anomalous dispersion was used for resonant scattering. In macromolecular crystallography the term anomalous scattering is used widely in place of resonant scattering.

== History ==

The resonant scattering of X-rays was theoretically predicted by Waller (Waller, I., 1928, ''Über eine verallgemeinerte Streuungsformel''. ''Z. Phys.'' '''51''', 213-231.) and first calculated by Hönl (Hönl, H., 1933, ''Zur Dispersionstheorie der Röntgenstrahlen''. ''Z. Phys.'' '''84''', 1-16; Hönl, H., 1933, ''Atomfactor für Röntgenstrahlen als Problem der Dispersionstheorie (K-Schale)''. ''Ann. Phys.'' (Leipzig), '''18''', 625-657.

[[Category:X-rays]]

← Older revision		Revision as of 17:01, 17 November 2017
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−	<~~Font~~ color="blue">Diffusion résonante</~~Font~~> (''Fr''). <~~Font~~ color="black">Diffusione risonante</~~Font~~> (''It''). <~~Font~~ color="purple"> 共鳴散乱</~~Font~~> (''Ja'')	+	<font color="blue">Diffusion résonante</font> (''Fr''). <font color="red">Resonante Streuung</font> (''Ge''). <font color="black">Diffusione risonante</font> (''It''). <font color="purple">共鳴散乱</font> (''Ja'').
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	== Definition ==		== Definition ==

@@ Line 1: / Line 1: @@
 <Font color="blue">Diffusion résonante</Font> (''Fr''). <Font color="black">Diffusione risonante</Font> (''It''). <Font color="purple"> 共鳴散乱</Font> (''Ja'')
 == Definition ==
-The elementary theory of the scattering of X-rays by atoms, leading to the real atomic scattering factor <math>f_o</math>, applies only for X-radiation whose wavelength is far removed from that of any natural (resonant) frequency of the atom.  When this condition does not hold, one needs to use as physical model for the scattering that of a forced damped harmonic oscillator.  This leads to resonant-scattering terms in the full, now complex, scattering factor of an atom, represented by:-
+The elementary theory of the scattering of X-rays by atoms, leading to the real atomic scattering factor <math>f_o</math>, applies only for X-radiation whose wavelength is far removed from that of any natural (resonant) frequency of the atom. When this condition does not hold, one needs to use as physical model for the scattering that of a forced damped harmonic oscillator. This leads to resonant-scattering terms in the full, now complex, scattering factor of an atom, represented by:
 <math>f=f_o + f\,' + if\,''</math> .
-The real and imaginary terms, <math> f\,', f\,''</math>, in the atomic scattering factor are independent of sin(&theta;)/&lambda; and in general small compared to <math>f_o</math>.
+The real and imaginary terms, <math> f\,', f\,''</math>, in the atomic scattering factor are independent of sin(&theta;)/&lambda; and in general small compared with <math>f_o</math>.
 The values of <math>f\,'</math> and <math>f\,''</math> change most at the absorption edge of the element in question.
-In the older literature the term <I>anomalous dispersion</I> was used for resonant scattering.  In macromolecular crystallography the term <I>anomalous scattering</I> is used widely in place of resonant scattering.
+In the older literature the term [[anomalous dispersion]] was used for resonant scattering.  In macromolecular crystallography the term [[anomalous scattering]] is used widely in place of resonant scattering.
 == History ==
-The resonant scattering of X-rays was theoretically predicted by Waller (Waller, I., 1928,  ''Über eine verallgemeinerte Streuungsformel''. ''Z. Phys.'' '''51''', 213-231.) and first calculated by Hönl (Hönl, H., 1933, ''Zur Dispersionstheorie der Röntgenstrahlen''. ''Z. Phys.'' '''84''', 1-16; Hönl, H., 1933, ''Atomfactor für Röntgenstrahlen als Problem der Dispersionstheorie (K-Schale)''. ''Ann. Phys.'' (Leipzig), '''18''', 625-657.
+The resonant scattering of X-rays was theoretically predicted by I. Waller [(1928).  ''Z. Phys.'' '''51''', 213-231. ''Über eine verallgemeinerte Streuungsformel''] and first calculated by H. Hönl [(1933). ''Z. Phys.'' '''84''', 1-16. ''Zur Dispersionstheorie der Röntgenstrahlen''; Hönl, H. (1933). ''Ann. Phys.'' (Leipzig), '''18''', 625-657. ''Atomfactor für Röntgenstrahlen als Problem der Dispersionstheorie (K-Schale)''].
@@ Line 22: / Line 21: @@
 == See also ==
-[[anomalous dispersion]]<br>
+[[Anomalous dispersion]]<br>
-[[anomalous scattering]]<br>
+[[Anomalous scattering]]<br>
-[[multiwavelength anomalous diffraction (MAD)]]
+[[Multiwavelength anomalous diffraction (MAD)]]

← Older revision		Revision as of 05:39, 4 March 2015
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	[[Category:X-rays]]<br>		[[Category:X-rays]]<br>
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		+
		+	== See also ==
		+	[[anomalous dispersion]]<br>
		+	[[anomalous scattering]]<br>
		+	[[multiwavelength anomalous diffraction (MAD)]]

← Older revision		Revision as of 05:35, 4 March 2015
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		+	<Font color="blue">Diffusion résonante</Font> (''Fr''). <Font color="black">Diffusione risonante</Font> (''It''). <Font color="purple"> 共鳴散乱</Font> (''Ja'')
		+
		+
	== Definition ==		== Definition ==