Coherent background effect

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This phenomenon of peak energy being dependent on the crystal zone-axis orientation and beam energy is characteristic of coherent bremsstrahlung (CB). The effect is well known in x-ray diffraction. As described in previous chapters in EDX from crystals, some background may arise as a result of CB. The CB... 

In order to achieve a coherent discussion of these results it is instructive to consider them against the background of a molecular model of polymer motion, and to do this we have chosen the cooperative model of Adam and Gibbs 17). We shall consider in turn the measured values of activation energy, the effects of cross-linking, and finally multiple... 

If the isotope has no spin, then < b > = < b as < b> = b and there is no incoherent scattering for neutrons. Only coherent scattering contains information on the stmcture of the sample. The incoherent cross section contains no information on interference effects and forms an isotropic (flat) background which must be subtracted off in SANS stmctural investigations. While most of the atoms encountered in neutron scattering from polymers are mainly coherent scatterers (e.g., carbon, oxygen, deuterium), there is one important exception [8,22,23]. In the case of hydrogen (H )... 

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