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US-12618998-B2 - Systems and methods for generating high-energy three-dimensional computed tomography images of bulk materials

US12618998B2US 12618998 B2US12618998 B2US 12618998B2US-12618998-B2

Abstract

A system for inspecting an object, includes: a source of X-ray radiation; a horizontal array of detectors, wherein the source and the array of detectors are positioned substantially on a first plane; a platform configured to rotate as well as translate in a vertical trajectory, wherein the platform is positioned on a second plane between the source and the array of detectors, and wherein the object is disposed on the platform; and a computing device configured to: cause the source to fire a substantially horizontal fan beam in a third plane, wherein the third plane is above a top of the object; acquire calibration data from the array of detectors while the third plane is above the top of the object; cause the platform to simultaneously rotate and raise the object vertically upwards; acquire scan data of the object; and generate a three dimensional scan image of the object.

Inventors

  • Mark Procter

Assignees

  • RAPISCAN HOLDINGS, INC.

Dates

Publication Date
20260505
Application Date
20230913

Claims (20)

  1. 1 . A system for inspecting an object, comprising: a source of X-ray radiation; a horizontal array of detectors, wherein the source and the array of detectors are positioned substantially on a first plane, and wherein the array of detectors has channels or pixels ranging from 1 to 20; a platform configured to rotate and configured to translate in a vertical trajectory, wherein the platform is positioned on a second plane between the source and the array of detectors, wherein the platform is adapted to receive and support the object, and wherein a rate or speed of vertical translational of the platform is based on a radiation dose output of the source being below 0.5 uSv per hour; and a computing device configured to: cause the source to fire a substantially horizontal fan beam of X-rays in a third plane, wherein the third plane is above a top of the object; acquire calibration data from the array of detectors while the third plane is above the top of the object; cause the platform to simultaneously rotate and raise the object vertically upwards; acquire scan data of the object; and use the calibration and scan data to generate a three dimensional scan image of the object.
  2. 2 . The system of claim 1 , wherein the object is a densely packed Unit Load Device or a pallet.
  3. 3 . The system of claim 1 , wherein the source is a LINAC or Betatron configured to operate at an energy ranging from approximately 750 keV and up to 10 MeV.
  4. 4 . The system of claim 1 , wherein the source has a dose output ranging from 0.01 Gy/min to 30 Gy/min.
  5. 5 . The system of claim 1 , wherein the source includes a secondary collimator configured to generate the horizontal fan beam of X-rays.
  6. 6 . The system of claim 1 , wherein the array of detectors is 1 to 6 channels or pixels tall.
  7. 7 . The system of claim 1 , wherein the array of detectors is 8 to 12 channels or pixels tall.
  8. 8 . The system of claim 1 , wherein the system has a magnification of approximately 1.525 and a reconstructed resolution of about 22 mm per slice.
  9. 9 . The system of claim 1 , wherein the system has a throughput of at least 5 units per hour.
  10. 10 . The system of claim 1 , wherein the platform includes a first drive mechanism configured to rotate the object at a first rotational speed and a second drive mechanism configured to rotate the object at a second rotational speed.
  11. 11 . The system of claim 10 , wherein the first rotational speed ranges from about 5 minutes a rotation to 30 seconds a rotation, and wherein the second speed ranges from about 30 seconds a rotation to 0.5 seconds a rotation.
  12. 12 . The system of claim 10 , wherein the platform further includes a corkscrew/scissor lift that raises or lowers the object.
  13. 13 . The system of claim 10 , wherein the platform further includes a hoist that is raised and lowered though a piston assembly for raising or lowering the object.
  14. 14 . A method of inspecting an object using a platform positioned between a source of X-ray radiation and a horizontal detector array, the method comprising: transporting the object over a conveyor to position the object on the platform; triggering the source to fire a horizontally diverging fan beam, wherein a plane of the fan beam is above a top surface of the object; acquiring calibration data using the detector array, wherein the array of detectors has channels or pixels ranging from 1 to 20; causing the platform to rotate as well as rise vertically upwards in order to move the object in a substantially helical trajectory, wherein a rate or speed of vertical movement of the platform is based on a radiation dose output of the source being below 0.5 uSv per hour; acquiring scan data by exposing the moving object to the fan beam; and generating, using the calibration and scan data, a three dimensional scan image of the object.
  15. 15 . The method of claim 14 , wherein the object is a densely packed Unit Load Device or a pallet.
  16. 16 . The method of claim 14 , wherein the source is a LINAC or Betatron configured to operate at an energy ranging from approximately 750 keV and up to 10 MeV.
  17. 17 . The method of claim 14 , wherein the source has a dose output ranging from 0.01 Gy/min to 30 Gy/min.
  18. 18 . The method of claim 14 , wherein the source includes a secondary collimator configured to generate the horizontal fan beam of X-rays.
  19. 19 . The method of claim 14 , wherein the detector array is 1 to 6 channels or pixels tall.
  20. 20 . The method of claim 15 , wherein the detector array is 8 to 12 channels or pixels tall.

Description

CROSS-REFERENCE The present specification relies on U.S. Patent Provisional Application No. 63/375,900, titled “Systems and Methods for Generating High-Energy Three-Dimensional Computer Tomography Images of Bulk Materials” and filed on Sep. 16, 2022, for priority. The above-mentioned application is herein incorporated by reference in its entirety. FIELD The present specification is related generally to the field of X-ray inspection. More specifically, the present specification is related to systems and methods for moving an object vertically in a helical trajectory past a horizontal fan beam of X-rays in order to generate a three-dimensional scan image of the object. BACKGROUND It has become evident in recent years that the approach adopted for inspection of personnel luggage, both “carry on” and “hold” baggage, is insufficient for fully characterizing the contents of larger aviation packages. Unit Load Devices (ULDs) are containers used to load luggage, freight, and mail on wide body aircrafts. ULDs range in size, but are typically no larger than 2 m in width, 1 m in length and about 1.5 m in height. Such large dimensions require X-ray penetration power far greater than that afforded by <200 keV source solutions employed in baggage scanners. Even up to 1 MeV scanning solutions are limited by a penetration capability of <100 mm steel equivalent, which prevents complete inspection of high-density, or highly packed, large ULD type containers. Air Cargo operations also require the use of dual or multi-sided inspection technologies in order to provide operators with a complete visualization of the object under inspection and the potential threat or contraband materials within. This requirement is of particular importance and benefit when considering larger, more heavily packed and dense cargo, where objects can overlap and “clutter” the inspection view from many angles. Indeed, when considering checked baggage, where the most stringent of ECAC (European Civil Aviation Conference) regulations (and equivalent TSA (USA Transportation Security Administration) regulations) are in place, most airports are required to utilize CT (Computed Tomography) imaging technologies. CT imaging for items up to and including those of personnel hold luggage can be achieved using similar energies to those of hand-luggage scanners, or in the energy range of <200 keV. This is due in part to the maximum size of the bags under inspection and in part to the typical low-density materials that people pack into their travel bags—that is, clothing, toiletries, and other typical consumer items. However, for larger consignments that may include much denser and closely packed objects such as, for example, lithium batteries, food stuffs, and electronics equipment, a 200 keV source does not provide sufficient penetration capabilities to adequately image the package. Recently, there has been an increase observed in the shipment of drugs contained within palletized food stuffs, therefore a similar solution to that of the above-described market sector is required to provide complete inspection of palletized freight. ISO guidelines recommend that pallets are no larger in size than 1100 mm×1220 mm×1830 mm (length×width×height). For transportation of relatively high-density fruits, with high packing fractions, a penetration thickness of 1.1 m can correspond to an equivalent steel thickness of upwards of 300 mm. Such penetrative capability requires the use of high-energy solutions in order to achieve the necessary contrast and detection capabilities for inspection. This requirement introduces a number of complexities in the solution that can be adopted to provide 3D imaging capabilities, in addition to driving significant additional cost in the increased technical capability of the imaging solution and the management and shielding of the larger X-ray dose emission. The majority of CT imaging solutions rely on the ability to rotate the X-ray source and detector assemblies at high speed. This works well for low-profile X-ray sources, such as tubes or simple emitter devices, but does not scale well to high-energy sources in the ˜6 MeV range. Similarly, static CT imaging devices, which employ multiple individual X-ray sources, do not provide a comparable solution that can be sought with the much larger and unwieldly MeV solutions. Accordingly, there is a need for an X-ray imaging system and method that incorporates fixed-inspection hardware, while providing a 3D image of the object under inspection. There is also a need for the X-ray imaging system and method to rely upon motion of the object under inspection, eliminating the need to move the inspection hardware and the need to employ multiple X-ray source and detector configurations, as the many angles at which the object is imaged are generated through the motion of the object itself. SUMMARY The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and