SAXS uses Cu Ka X-ray scattering at very small angles to probe structure in zones of electron density contrast with sizes in the range of 1nm to 100nm. Such structures can include particulate systems, multi-phase systems, pore structures, emulsions, biological and cellular structures and others. Information about size, shape, dispersity, periodicity, interphase boundary area and solution properites can be obtained. Specimens may be solids, films, powders, liguids, gels, crystalline or amorphous. Applications in polymers and biological samples are abundant and well known.