Inspection equipment using small-angle topography in determining an object's internal structure and composition
First Claim
1. A small-angle topography device comprising:
- a source of penetrating radiation;
a collimator that forms scan beams from the penetrating radiation, the collimator being a regular periodic structure consisting of transparent regions alternating with the opaque regions;
a facility for scanning an object through the scan beams to obtain a complete projection of the object;
a spatial filter positioned behind the object, the spatial filter having a regular periodic structure complementary to that of the collimator so that regions of the spatial filter that correspond to the transparent regions of the collimator are opaque to the penetrating radiation the opaque regions of the spatial filter being disposed to block portions of the scan beams that pass through the object without deflection, transparent regions of the spatial filter being disposed to transmit portions of the scan beams that the object deflects at small angles;
a coordinate-sensitive detector positioned to detect radiation that the spatial filter transmits during scanning; and
a processing system that uses measurements from the coordinate-sensitive detector during the scanning, to determine a three-dimensional internal structure of the object.
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Accused Products
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.
121 Citations
31 Claims
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1. A small-angle topography device comprising:
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a source of penetrating radiation; a collimator that forms scan beams from the penetrating radiation, the collimator being a regular periodic structure consisting of transparent regions alternating with the opaque regions; a facility for scanning an object through the scan beams to obtain a complete projection of the object; a spatial filter positioned behind the object, the spatial filter having a regular periodic structure complementary to that of the collimator so that regions of the spatial filter that correspond to the transparent regions of the collimator are opaque to the penetrating radiation the opaque regions of the spatial filter being disposed to block portions of the scan beams that pass through the object without deflection, transparent regions of the spatial filter being disposed to transmit portions of the scan beams that the object deflects at small angles; a coordinate-sensitive detector positioned to detect radiation that the spatial filter transmits during scanning; and a processing system that uses measurements from the coordinate-sensitive detector during the scanning, to determine a three-dimensional internal structure of the object. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A small-angle topography device comprising:
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a source of penetrating radiation forming an incident radiation flux as a plurality of separated beams falling on an object to be analyzed; a spatial filter for the plurality of separate beams, the spatial filter including a plurality of plates behind the object; and a plurality of detector elements in slits formed between the plates. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A device for determining composition and internal structure of an object, comprising:
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a source of penetrating radiation; a collimation system that shapes radiation flux from the source and directs radiation toward the object; a scanning system for moving the object relative to the source; a first detector system that measures undeflected radiation transmitted through the object and identifies a distribution of absorption factor of the object; and a second detector system that measures radiation scattered at small angles, under 1°
, in the object and identifies a plurality of scattering curves for the object. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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22. A device for determining composition and internal structure of an object, comprising:
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a source of penetrating radiation; a collimation system that shapes radiation flux from the source and directs radiation toward the object; a scanning system for moving the object relative to the source; a first detector system that measures undeflected radiation transmitted through the object and identifies a distribution of absorption factor of the object; and a second detector system that measures radiation scattered at small angles in the object and identifies a plurality of scattering curves for the object, wherein the second detector system comprises a two-dimensional coordinate sensitive detector and a spatial filter positioned between the detector and the object, the spatial filter having opaque regions positioned to block radiation transmitted through the object without deflection and transparent regions positioned to transmit to the detector radiation that the object deflects at small angles.
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23. A device for determining composition and internal structure of an object, comprising:
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a source of penetrating radiation; a unit for shaping a radiation flux directed to the object; a plurality of plates that form slits behind the object; a first plurality of detector elements positioned in the slits between the plates to record radiation transmitted undeflected through the object; and a second plurality of detector elements positioned in the slits between the plates to record radiation scattered at small angles in the object wherein the plurality of plates prevent undeflected radiation from reaching the second plurality of detector elements; and a processing system coupled to the first and second pluralities of detector elements, wherein the processing system forms an image of the object based on measurements of recorded radiation transmitted undeflected through the object and scattered at small angles in the object. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31)
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Specification