ABSTRACT
In a typical SAXS experiment, a two-dimensional (2D) X-ray detector is placed a few meters away from the sample to detect scattered X-rays at small angles. Only a small part of the X-rays are scattered by the sample, while most of the incident X-ray beam (primary beam) travels through the sample. Currently available positionsensitive SAXS detectors can get saturated or spoiled if the primary beam hits the detector, therefore a beamstop must be positioned carefully in front of the detector to receive the whole primary beam. Figure 4.1 shows a schematic drawing of a SAXS setup with a wideangle X-ray scattering (WAXS) option. The basic SAXS setup can be extended and modified to include other methods such as WAXS, fluorescence spectroscopy, infrar ed spectroscopy, and so forth. The sample environment can accommodate setups for various in situ experiments, starting from simple heating and stretching experiments all the way to novel stopped-flow mixing cells or even rheology. In principle, there are no limitations; one only needs to be able to put the X-ray beam through the cell somehow and leave some space for the scattering that comes out.
