Sensing small angle scattering with an X-ray grating interferometer

Abstract

Ultra small angle scattering is a powerful tool for the study of the micro-structure of materials at a length scale below the resolution of standard x-ray detectors. Current methods like Small Angle X-ray Scattering (SAXS) are usually slow and there­fore inadequate to industrial environments. A recently developed x-ray imaging method based on the Talbot-Lau interferometer allows for the full field measurement of the refraction and local small angle scattering of the x-ray beam within the object. The method is compatible with standard x-ray tubes and as such, a good candidate for industrial implementation. In the following manuscript, we report on the use of the x-ray Talbot-Lau interferometer for the measurement of the local small angle scattering power. Two applications relevant to homeland security are presented. First, we show how the measurement of the local small angle scattering power complements the con­ventional absorption-based radiography and helps to distinguish explosives from standard fail objects. Finally, we demonstrate that information can be coded within the scattering pattern of a manufactured marker. Such marker can be placed in critical objects, such as drugs boxes or luxury goods, in order to avoid the circulation of fakes.