Neutron scattering incoherent

If one wanted to predict slow neutron incoherent scattering from CO then, in the Gaussian approximation, all one would need would be the... 

Optical (i.e. infrared and Raman) techniques are, generally, most sensitive to vibrations involving the heavier atoms, because of the number of their electrons. The neutron incoherent scattering cross section of hydrogen is uniquely high, and makes it about ten times more visible than any other atom. 

H. H. Chen-Mayer, D.F.R. Mildner, G.P. Lamaze R.M. Lindstrom (2002). J. Appl. Phys., 91, 3669-3674. Imaging of neutron incoherent scattering from hydrogen in metals. 

Kinugawa K, Othori N, Kadono K et al (1993) Pulsed neutron diffraction study on the structures of glassy LiX-KX-CsX-BaX2 (X=Q, Br, I). J Chem Phys 99 5345-5351 NodaY, Nakao H, Terauchi H (1995) Neutron incoherent scattering of structural glass NH4I-KI mixed crystal. Physica B 213-214 564-566... 

Two contributions to Eq. (8) can be identified, the first of these is b > — ) and represents the mean square deviation of individual scattering lengths from the average value. As such it is called the incoherent scattering cross section and constitutes a uniform, isotropic background scattering since it retains no information on the phase of the scattered neutrons. Incoherent scattering cross sections are tabulated as values of a. where ... 

To determine Gm( or Gx( r), it is preferable to work with solutions of heavy water (D2O) because of the prohibitively large neutron incoherent scattering of the proton (H) spins, and the large inelastic scattering from the proton nuclei in H2O. 

The prerequisite for an experimental test of a molecular model by quasi-elastic neutron scattering is the calculation of the dynamic structure factors resulting from it. As outlined in Section 2 two different correlation functions may be determined by means of neutron scattering. In the case of coherent scattering, all partial waves emanating from different scattering centers are capable of interference the Fourier transform of the pair-correlation function is measured Eq. (4a). In contrast, incoherent scattering, where the interferences from partial waves of different scatterers are destructive, measures the self-correlation function [Eq. (4b)]. 

Measurements of the self-correlation function with neutrons are normally performed on protonated materials since incoherent scattering is particularly strong there. This is a consequence of the spin-dependent scattering lengths of hydrogen. Due to spin-flip scattering, which leads to a loss of polarization, this... 

The spin-incoherent scattering (prominent for protons) involves a change of the spin-state of the scattered neutrons (spin-flip scattering) with a probability of%. 

Intensities of coherently and incoherently scattered neutrons are described by the scattering function S and have been worked out by [S.W. Lovesey (1986) K.S. Singwi, A. SjOlander (1960) R.E. Lechner, C. Riekel (1981)] as... 

Figure 16-16. Neutron scattering spectrum of a-Ag2Se single crystal at 250 °C. The solid line gives the calculated incoherent scattering (after [K. Funke (1989)]).

The first function, S(k, to) contributes to the coherent scattering, and the second function, Ss(k, to), contributes to the incoherent scattering of the neutrons. Neutrons consequently probe the spontaneous fluctuations of the property... 

See also, Bacon, G.E. "Thermal Neutron Diffraction", 3rd ed. Oxford University Press Oxford, 1976, for a discussion of spin-incoherent scattering as well as other aspects of the theory and practice of neutron scattering. 

Amount of absorbed hydrogen was checked by thermodesorption method. All samples were analyzed by powder X-ray diffraction using a ThermoARL diffractometer (/.( ll 1.5406 A). Neutron data were obtained on DISK diffractometer at the Kurchatov Science Centre)). Deuterium rather than hydrogen has been used in order to reduce the incoherent scattering. Obtained results were refined with Fullprof and Rietan programs. 

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