Theoretical aspects on the anomalous dispersion factors of x-rays

2005 ◽  
pp. 32-39
Keyword(s):  
Anomalous Dispersion ◽  
X Rays

Anomalous Dispersion in the Field of X-Rays

Nature ◽  
1925 ◽  
Vol 115 (2881) ◽  
pp. 85-86
Author(s):  
ELIS HJALMAR ◽  
MANNE SIEGBAHN
Keyword(s):  
Anomalous Dispersion ◽  
X Rays

Anomalous Dispersion of X-Rays in Calcite

1938 ◽  
Vol 54 (12) ◽  
pp. 988-993
Author(s):  
Robert M. Whitmer ◽  
George A. Lindsay
Keyword(s):  
Anomalous Dispersion ◽  
X Rays

X-RAYS DIFFRACTION STUDY OF BINARY METALLIC Cu-Y GLASSES USING ANOMALOUS DISPERSION

1985 ◽  
Vol 46 (C8) ◽  
pp. C8-157-C8-161 ◽  
Author(s):  
M. Laridjani ◽  
P. Leboucher ◽  
D. Raoux ◽  
J. F. Sadoc
Keyword(s):  
Diffraction Study ◽  
Anomalous Dispersion ◽  
X Rays

scholarly journals Anomalous dispersion and absorption of X-rays

1934 ◽  
Vol 143 (849) ◽  
pp. 358-376 ◽  
Keyword(s):  
Oscillator Strength ◽  
Anomalous Dispersion ◽  
General Nature ◽  
X Rays ◽  
Theoretical Relation ◽  
General Applicability ◽  
Classical Oscillator ◽  
Special Cases ◽  
Experimental Values ◽  
Second Procedure

The general nature of the anomalous dispersion of X-rays, and its relation to absorption, was considered by Kallmann and Mark in 1927. The purpose of this paper is first to make more detailed calculations of the dispersion for certain special cases; secondly, to consider the theroretical reasons foe the observed value of the oscillator strength, particularly the equivalence of the 2K electrons to about 1.3 classical electrons. By virtue of the general applicability of the electromagnetic theory of radiation an atom in quantum mechanics is in many respects equivalent to an multitude of classical oscillator. The dispersion and absorption of radiation by the atom depend upon the frequency and strength of these virtual oscillators. In calculating the dispersion of X-rays there are two courses open. We can either use approximate estimates of the theoretical quantum-mechanical strength of the oscillators concerned, or use the theoretical relation which exists between the oscillator strength and the intensity of absorption of radiation, and assume the experimental values of the latter. The second procedure is possible since the necessary experimental data are available, and we adopt accuracy with which the theoretical oscillator strength can be evaluated. Kallmann and Mark, in their treatment of dispersion, also adopt the same procedure so far as they assume that the variation of the oscillator strength with frequency corresponds to the λ 3 -law of photoelectric absorption. The dispersion calculated in this way is only partially dependent on theory.

scholarly journals The atomic scattering factor for X-rays in the region of anomalous dispersion

1933 ◽  
Vol 139 (838) ◽  
pp. 459-466 ◽  
Keyword(s):  
Free Electron ◽  
Scattered Radiation ◽  
Wave Length ◽  
Anomalous Dispersion ◽  
X Rays ◽  
Characteristic Frequencies ◽  
X Ray ◽  
Atomic Scattering Factor ◽  
Atomic Scattering ◽  
Scattering Factor

The atomic scattering factor ( f -factor) for X-rays is the ratio of the amplitude of the X-rays scattered by a given atom and that scattered according to the classical theory by one single free electron. It is given as a function of sin ϑ/λ, λ being the wave-length of the X-rays, 2ϑ the angle between the primary and the scattered radiation. It is assumed to be independent of the wave-length so long as sin ϑ/λ remains constant. Recently, however, it has been shown both theoretically and experimentally that the last assumption is no longer valid, when the scattered frequency is in the neighbourhood of one of the characteristic frequencies of the scattering element. The first to show the influence of the anomalous dispersion on the f factor were Mark and Szilard, who reflected strontium and bromine radiations by a rubidium bromide crystal. Theoretically the problem was dealt with by Coster, Knol and Prins in their investigation of the influence of the polarity of zincblende on the intensity of X-ray reflection and later on once more by Gloeker and Schäfer.

Resonant Scattering in Condensed Matter, Experiments that Reveal Short to Long Range Atomic Order

2016 ◽  
Vol 230 (3) ◽  
Author(s):  
Jean-François Bérar ◽  
Nathalie Boudet ◽  
Nils Blanc ◽  
Shinya Hosokawa
Keyword(s):  
Long Range ◽  
Condensed Matter ◽  
Resonant Scattering ◽  
Anomalous Dispersion ◽  
Disordered Materials ◽  
X Rays ◽  
Atomic Order ◽  
Dispersion Effect ◽  
Experimental Conditions ◽  
Range Atomic Order

AbstractAfter a historical introduction of the anomalous dispersion effect, the formalism used to investigate disordered materials using the resonant scattering of X-rays is exposed. As these experiments are sensitive to the experimental conditions, some experimental settings are discussed.

The anomalous dispersion of X-rays by single crystal ZnSe

1971 ◽  
Vol 6 (7) ◽  
pp. 1007-1011 ◽  
Author(s):  
K. F. Burr ◽  
J. Woods
Keyword(s):  
Single Crystal ◽  
Anomalous Dispersion ◽  
X Rays
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