Abstract

We describe neutron scattering in a space–time frame-complementary to the van Hove picture. Based on the theory of partial coherence from light optics, neutron beams may be represented by correlation volumes, which are defined by the wavelength distribution and by optical elements like guides, slits, choppers or crystals. Size and shape of these tiny volumes (in space and time) determine the volume of coherent interaction within the samples, which are represented by pair correlation functions. The beam correlation volumes also determine the resolution of the experiment and if the signal is proportional to a Fourier transform of the sample correlation function. Here we give a simple approach to this theory with various examples.

Author Keywords: Neutron scattering; Partial coherence; Cittert–Zernike theorem

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