My first electron density map: A beginner's guide to small angle X-ray diffraction

Small angle X-ray diffraction (SAXD) is a non-destructive, analytical method which reveals nanostructural information on the studied material in the form of its electron density distribution, and when applying furthermore peak-shape analysis allows even to retrieve mechanical properties. This technique bases on observing the diffracted intensity of X-rays from a specimen as a function of the scattering angle, 2. Typically, with SAXD it is possible to visualize the sample structure up to a resolution of few Ångströms (1 Å = 10-10 m). In this short guide, the main steps of data reduction and analysis are illustrated on a synthetic membrane/water system. The chosen system is 1-dimensional (1D) and centrosymmetric, which keeps the data analysis as simple as possible, but nevertheless all principle steps from data acquisition to the determination of the electron density map are given.