Inspection equipment using small-angle topography in determining an

Abstract

Devices for X-ray topography determine structures and compositions of objects. In accordance with an embodiment of the invention, a scanning system forms images using small angle scattering. A spatial filter selects radiation an object scatters at small angles and blocks other radiation. A coordinate-sensitive detector behind the filter records the scattered radiation. An object image is constructed based on the small-angle scattering information and the compositions of regions of the object are determined from scattering curves for the regions. One embodiment of the invention includes a source of penetrating radiation, a detector system for radiation transmitted through an analyzed object, a detector system for radiation the object scatters at small angles, and a unit for moving the object during scanning. A three-dimensional absorption factor distribution is determined for the object by X-raying the object at different angles. Small-angle scattering curves are obtained for separate volume elements of the object. The scattering curve for a volume element is compared to a data base of scattering curves for known substances to identify the composition of the element. A three-dimensional image of the object's internal structure has the substances composing the object identified. A unit shaping the radiation flux to the object can be two separate sets of collimators. One set forms fan beams for scanning the object and forming an image based on radiation absorption. The other set of collimators forms beams for imaging based on small-angle scattering and includes a series of multislit collimators. The collimators' axes are at different angles with the object motion direction. Each multislit collimator forms flat weakly diverging fan-shaped beams. Two-dimensional coordinate-sensitive detectors with a spatial filter positioned before each of the detectors record the scattered radiation.