Development of an ultra-small-angle X-ray scattering instrument for probing the microstructure and the dynamics of soft matter

A Bonse-Hart camera suitable for studying dilute and weakly scattering systems has been developed. The required level of reduction of the parasitic background scattering was realised by replacing channel-cut crystals by a pair of polished and deeply etched parallel crystals. The performance of this ultra-small-angle X-ray scattering instrument is illustrated by means of two examples: the microstructure of a short-range attractive colloidal system; and the growth dynamics of soot particles in a diffusion flame. In addition, the feasibility of performing dynamic X-ray scattering experiments is demonstrated.