Traveling X-ray inspection system with collimators
View Patent ↗An X-ray apparatus is provided for inspecting a cargo container. The apparatus includes a moveable platform with an X-ray source and X-ray detector disposed on the platform on opposing sides of a scanning zone where the scanning zone may be moved along a length of the cargo container to scan a volume of the cargo container, said X-ray source being disposed in a spaced-apart relationship with respect to the scanning zone. The X-ray apparatus also includes a precollimator disposed on the X-ray platform between the X-ray source and scanning zone, said precollimator being located proximate the scanning zone and an intermediate collimator disposed midway between the X-ray source and the precollimator, said intermediate collimator having a spaced-apart relationship with respect to the precollimator and to the X-ray source.
1. An X-ray apparatus for inspecting an object, such apparatus comprising:
an X-ray source and X-ray detector disposed on opposing sides of a scanning zone, said X-ray source being disposed in a spaced-apart relationship with respect to the scanning zone;
a first collimator that is disposed between the X-ray source and the scanning zone and that is located proximate the X-ray source, wherein the first collimator is in addition to any collimator that is integral to the X-ray source;
a precollimator disposed between the first collimator and the scanning zone, said precollimator being located proximate the scanning zone; and
at least one intermediate collimator disposed between the first collimator and the precollimator, said intermediate collimator having a spaced-apart relationship with respect to the precollimator and the first collimator and being substantially stationary with respect to the precollimator.
2. The X-ray apparatus as in claim 1 wherein the intermediate collimator further comprises a pair of wings for intercepting backscatter operatively extending from opposing sides of a collimating slot of the intermediate collimator towards the X-ray source.
3. The X-ray apparatus as in claim 2 wherein the pair of wings further comprises a mounting position that is set back from a center line of a collimating entrance of the intermediate collimator by a distance such that the pair of wings intercept at least a portion of an X-ray beam penumbra from a previous collimator.
4. The X-ray apparatus as in claim 3 wherein the pair of wings has a thickness that is sufficient to block at least a substantial majority of radiation that is scattered from an intermediate collimator surface that faces the X-ray source.
5. The X-ray apparatus as in claim 2 wherein the intermediate collimator further comprises an overall width that is at least equal to a collimating entrance of the intermediate collimator, plus twice a setback of the pair of wings, plus twice a thickness of the pair of wings.
6. The X-ray apparatus as in claim 1 wherein the precollimator further comprises a pair of wings for intercepting backscatter operatively extending from opposing sides of a collimating slot of the precollimator towards the X-ray source.
7. The X-ray apparatus as in claim 6 wherein the set back of the pair of wings from the centerline of the collimating entrance of the precollimator further comprises a distance between the wings such that the pair of wings at least substantially intercept a penumbra of an X-ray beam from a previous collimator.
8. The X-ray apparatus as in claim 1 wherein the precollimator further comprises a pair of wings for intercepting backscatter operatively extending from opposing sides of a collimating slot of the precollimator towards the X-ray source and wherein the precollimator has an overall width that is at least equal to a collimating entrance of the precollimator, plus twice a setback of the pair of wings, plus twice a thickness of the pair of wings.
9. The X-ray apparatus as in claim 8 wherein the setback of the pair of wings further comprises a distance between edges of the X-ray beam and the pair of wings to thereby accommodate misalignment of the precollimator.
10. The X-ray apparatus as in claim 1 wherein the detector further comprises a postcollimator that supports a set of detector elements, said postcollimator further comprising a pair of wings for intercepting backscatter operatively extending from opposing sides of a front face of the set of detectors towards the X-ray source.
11. The X-ray apparatus as in claim 10 wherein the postcollimator further comprises a pair of wings for intercepting backscatter operatively extending from opposing sides of a collimating slot of the postcollimator towards the X-ray source and wherein the set back of the pair of wings from the centerline of the collimating entrance of the postcollimator further comprises a distance such that the pair of wings at least substantially intercept an X-ray beam penumbra from a previous collimator.
12. The X-ray apparatus as in claim 11 wherein the setback of the pair of wings further comprises a distance between edges of the X-ray beam and the pair of wings to thereby accommodate misalignment of the postcollimator.
13. The X-ray apparatus as in claim 1 wherein the first collimator comprises a source collimator that is disposed adjacent but not integral to the X-ray source.
14. The X-ray apparatus as in claim 13 wherein the source collimator further comprises a collimating slot with an entrance having a width that is approximately one percent of a distance from a point of origin of X-rays from the X-ray source to the entrance of the source collimator.
15. The X-ray apparatus as in claim 14 wherein the source collimator further comprises a collimating slot with an exit having a width that is less than one percent of a distance from the point of origin of the X-ray source to the exit of the source collimator.
16. The X-ray apparatus as in claim 1 wherein the intermediate collimator further comprises a collimating slot with an entrance having a width that is less than one-half percent of a distance from the X-ray source to the entrance of the intermediate collimator.
17. The X-ray apparatus as in claim 16 wherein the intermediate collimator further comprises the collimating slot with an exit having a width that is about one-third percent of a distance from the X-ray source to the exit of the source collimator.
18. The X-ray apparatus as in claim 1 wherein the precollimator further comprises a collimating slot with an entrance having a width that is about one-tenth percent of a distance from the X-ray source to the entrance of the precollimator.
19. The X-ray apparatus as in claim 18 wherein the precollimator further comprises the collimating slot with an exit having a width that is larger than the entrance.
20. The X-ray apparatus as in claim 1 wherein the precollimator further comprises a collimating slot with an entrance having a width that is about 0.05 percent of a distance from the X-ray source to the entrance of the precollimator.
21. The X-ray apparatus as in claim 1 wherein the first collimator further comprises a collimating slot having an exit having a width that is larger than an entrance to the collimating slot.
22. The X-ray apparatus as in claim 1 wherein the intermediate collimator further comprises a collimating slot having an exit having a width that is larger than an entrance to the collimating slot.
23. A method for inspecting an object, such method comprising the steps of:
providing an X-ray source and X-ray detector on opposing sides of a scanning zone, said X-ray source being disposed in a spaced-apart relationship with regard to the scanning zone;
disposing a first collimator proximal to the X-ray source and between the X-ray source and the scanning zone;
disposing a precollimator between the first collimator and the scanning zone, said precollimator being located proximate the scanning zone;
disposing an intermediate collimator between the first collimator and the precollimator, which intermediate collimator is stationary with respect to the first collimator; and
inspecting the object by transmitting an X-ray beam from the X-ray source to the X-ray detector using the first collimator, the intermediate collimator and the precollimator to control expansion and scatter of the X-ray beam.
24. The method as in claim 23 further comprising providing a pair of wings on opposing sides of a collimator slot of the intermediate collimator to control backscatter.
25. The method as in claim 23 further comprising providing a pair of wings on opposing sides of a collimator slot of the precollimator to control backscatter.