Small-angle techniques

Abstract

Small-angle X-ray scattering is discussed in the first part of this chapter. After a description of the general principles of the technique, small-angle scattering by monodisperse and polydisperse systems is considered. Instrumentation, data interpretation and the use of simulations and model calculations are also discussed. In the second part of the chapter, neutron small-angle scattering is described, placing the emphasis on specific differences between the use of X-rays and neutrons. These concern means of contrast variation (by labelling the matrix and/or the scattering object), magnetic and nuclear-spin dependent scattering, and the use of bulky sample environments. Specific techniques using the various means of creating contrast are presented, in particular label triangulation and triple isotopic replacement. Neutron small-angle scattering data can easily be put on an absolute scale, and radiation damage is not an issue. This chapter is also available as HTML from the International Tables Online site hosted by the IUCr.