Mobile X-ray inspection system for large objects

• US 5,764,683 A
• Filed: 02/12/1997
• Issued: 06/09/1998
• Est. Priority Date: 02/12/1996
• Status: Expired due to Term

• Current Assignee: American Science and Engineering Incorporated (OSI Systems Incorporated)
• Original Assignee: American Science and Engineering Incorporated (OSI Systems Incorporated)
• Inventors: Tybinkowski, Andrew, Swift, Roderick
• Primary Examiner(s): Wong, Don
• Application Number:
  US08/799,533
• Time in Patent Office: 482 Days
• Field of Search: 378/57, 378/58, 378/86, 378/87, 378/88, 378/193, 378/195, 378/196, 378/197, 378/198
• US Class Current: 378/57
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/04 and forming images of the material
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: G01N 23/20 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials
• CPC Class Codes: G01V 5/22 Active interrogation, i.e. by irradiating objects or goods using external radiation sources, e.g. using gamma rays or cosmic rays
• CPC Class Codes: G01V 5/222 measuring scattered radiation

Abstract

A device for inspecting a cargo container such as a motor vehicle or freight pallet, with penetrating radiation. A source of penetrating radiation is mounted on a moveable bed, thereby allowing a beam of penetrating radiation to sweep the large container. At least one detector is also mounted on the bed, ether on the side of the source or on a boom, so that, as the beam is scanned across the container, the container and any contents of the container are characterized by transmitted or scattered radiation, or both.

Claims

1. A device, for inspecting a cargo container with penetrating radiation, the device comprising:

a. a bed moveable along a first direction having a horizontal component;

b. a source of penetrating radiation, mounted on the bed, for providing a beam;

c. a motorized drive for moving the bed in the first direction; and

d. at least one scatter detector mounted on the bed, the at least one scatter detector having a signal output;

so that the beam is caused to traverse the cargo container as the bed is moved and the at least one scatter detector provides a signal for characterizing the cargo container and any contents of the cargo container.

2. A device according to claim 1, wherein the source of penetrating radiation is an x-ray source.

3. A device according to claim 1, wherein the at least one scatter detector is a backscatter detector.

4. A device according to claim 1, further comprising a transmission detector.

5. A device according to claim 1, wherein the at least one detector is a sidescatter detector.

6. A device according to claim 1, wherein the at least one scatter detector is a forward scatter detector.

7. A device according to claim 1, wherein the beam is a pencil beam scanned repeatedly along a second direction having a vertical component.

8. A device according to claim 1, further comprising:

(e) a boom, movably linked to the bed, the boom having a storage position, substantially fixed with respect to the bed, and an operation position that is transverse to the first direction, as well as an end region; and

(f) a beam catcher attached to the end region of the boom for impeding the further passage of penetrating radiation in the second direction when the boom is in the operation position.

9. A device according to claim 1, wherein the at least one scatter detector has upper and lower elements, the upper element being movably mounted with respect to the lower element, so that in a first position the upper element is transversely disposed with respect to the lower element and in a second position the upper element is substantially collinear with respect to the lower element.

10. A device according to claim 1, wherein the source of penetrating radiation provides a pencil beam that is scanned repeatedly over an angle of regard, the angle having an orientation with respect to the horizontal, the device further comprising:

a steering arrangement for steering the orientation of the angle of regard with respect to the horizontal.

11. A device according to claim 1, further comprising:

(a) a boom, movably linked to the bed, the boom having a storage position, substantially fixed with respect to the bed, and an operation position that is transverse to the first direction, as well as an end region; and

(b) a transmission detector attached to the end region of the boom to respond to penetrating radiation transmitted through the container, so as to provide a signal for forming a transmission image of the container.

12. A device according to claim 1, wherein the source of penetrating radiation includes an x-ray tube operating at a voltage in substantial excess of 200 kV.

13. A device according to claim 1, wherein the source of penetrating radiation includes an x-ray tube operating at a voltage in substantial excess of 350 kV.

14. A method, for producing an X-ray scatter image of a large object, the method comprising:

(e) providing a device having;

(i) a bed moveable along a first direction having a horizontal component;

(ii) a source of penetrating radiation, mounted on the bed, for providing a beam incident upon the large object;

(iii) a motorized drive for moving the bed in the first direction; and

(iv) at least one scatter detector mounted on the bed and having a signal output;

(f) using the motorized drive to move the device past an object so as to cause the object to be scanned; and

(g) processing the signal from the signal output of the scatter detector to form an image of the object.

15. A back scatter image of an object, the image formed by:

(h) providing a device having;

(i) a bed moveable along a direction having a horizontal component;

(ii) a source of penetrating radiation, mounted on the bed, for providing a beam incident upon the large object;

(iii) a motorized drive for moving the bed in the direction having a horizontal component; and

(iv) a scatter detector mounted on the bed and having a signal output;

(i) using the motorized drive to move the device past an object so as to cause the object to be scanned; and

(a) processing the signal from the signal output of the scatter detector to form an image of the object.

16. An image according to claim 15, wherein the object is a motor vehicle.

17. An image according to claim 15, wherein the motor vehicle has at least two pairs of wheels.

18. An image according to claim 15, wherein the object is a trailer.

19. An image according to claim 15, wherein the object is a railroad car.

20. An image according to claim 15, wherein the object is a freight pallet.

21. An image according to claim 15, wherein the object is a sea cargo container.

22. An image according to claim 15, wherein the object is an air cargo container.

23. An image according to claim 15, wherein the x-ray source includes an x-ray tube operating at a voltage in substantial excess of 200 kV.

24. A system for inspecting a cargo container with penetrating radiation, the system comprising:

(a) a vehicle having wheels and an engine for propelling the vehicle on highways;

(b) a source of penetrating radiation, mounted on the vehicle, for providing a beam;

(c) a motorized scan drive, distinct from the engine, for moving the vehicle in a first scan direction; and

(d) at least one scatter detector mounted on the vehicle, the at least one scatter detector having a signal output, so that the beam is caused to traverse the cargo container as the vehicle is moved in a scan direction and the at least one scatter detector provides a signal for characterizing the cargo container and any contents of the cargo container.

25. A system according to claim 24, further comprising a switchable gearbox for switchably coupling the engine and the motorized drive to the wheels.