X-Ray Scanner with Partial Energy Discriminating Detector Array

• US 20140192954A1
• Filed: 01/06/2014
• Published: 07/10/2014
• Est. Priority Date: 01/07/2013
• Status: Active Grant

• Current Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Original Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Inventors: Hanley, Gerard Andrew
• Granted Patent: US 9,823,383 B2
• Time in Patent Office: Days
• US Class Current: 378/57
• CPC Class Codes: G01V 5/224 Multiple energy techniques using one type of radiation, e.g. X-rays of different energies

Abstract

The present specification describes a scanning/inspection system configured as a dual-view system using dual-energy sensitive stacked detectors that are partially populated with multi-energy discriminating detectors for overall enhanced energy resolution and therefore improved discrimination of materials through better estimation of material physical properties such as density and effective atomic number.

Claims

1. A system for screening objects, comprising:

a) a receptacle for holding an object;

b) a conveyor to move the receptacle through an inspection region;

c) a first X-ray source for transmitting X-rays through the object for generating a vertical X-ray projection view of the said object;

d) a second X-ray source for transmitting X-rays through the object for generating a horizontal X-ray projection view of the said object;

e) a first set and a second set of transmission detectors for receiving the X-rays transmitted through the said object; and

f) a third and a fourth set of energy discriminating detectors for receiving the X-rays transmitted through the said object, wherein said third and fourth set of energy discriminating detectors are positioned such that they align with the object within the receptacle.

2. The system of claim 1 wherein the receptacle is a tray further comprising a foam insert that has at least one channel to align the said object for screening.

3. The system of claim 1 wherein the first and second transmission detectors are dual-energy sensitive stacked detectors.

4. The system of claim 1 wherein the third and fourth energy discriminating detectors are fabricated from high-Z semiconductor materials including cadmium-telluride (CdTe), cadmium-zinc-telluride (CZT), mercury iodide (HgI₂), selenium (Se), lead iodide (PbI₂), gallium arsenide (GaAs).

5. The system of claim 1 wherein the said object is a liquid, aerosol, gel (LAG) item.

6. The system of claim 1 further comprising a processor for receiving output signals from said first, second, third and fourth sets of detectors and overlaying said output signals onto a visual image of the said receptacle and object.

7. A method for screening objects, comprising:

a) providing a receptacle to hold and align an object;

b) moving the said receptacle through an inspection region using a conveyor;

c) generating a vertical X-ray projection view of the said object using a first X-ray source;

d) generating a horizontal X-ray projection view of the said object using a second X-ray source;

e) detecting X-rays transmitted through the said object using a first set and second set of transmission detectors; and

f) detecting X-rays transmitted through the said object using a third set and fourth set of energy discriminating detectors which are positioned such that they align with the object within the receptacle.

8. The method of claim 7 wherein the said receptacle is a tray further comprising a foam insert that has at least one channel to align the said object for screening.

9. The method of claim 7 wherein the said first and second set of transmission detectors are dual-energy sensitive stacked detectors.

10. The method of claim 7 wherein the said third and fourth set of energy discriminating detectors are fabricated from high-Z semiconductor materials including cadmium-telluride (CdTe), cadmium-zinc-telluride (CZT), mercury iodide (HgI₂), selenium (Se), lead iodide (PbI₂), gallium arsenide (GaAs).

11. The method of claim 7 wherein the said object is a liquid, aerosol, gel (LAG) item.

12. The method of claim 7 further comprising the step of processing the output signals from said first, second, third and fourth sets of detectors to form a visual image of the sad receptacle and object.

13. A system for screening objects, comprising:

a) a receptacle for holding an object;

b) a conveyor to move the receptacle through an inspection region;

c) an X-ray source for transmitting X-rays through the object for generating an X-ray projection view of the said object;

d) a plurality of transmission detectors for receiving the X-rays transmitted through the said object; and

e) a plurality of energy discriminating detectors for receiving the X-rays transmitted through the said object, wherein said plurality of energy discriminating detectors are positioned such that they align with the object within the receptacle.

14. The system of claim 13 wherein the receptacle is a tray further comprising a foam insert that has at least one channel to align the said object for screening.

15. The system of claim 13 wherein the plurality of transmission detectors are dual-energy sensitive stacked detectors.

16. The system of claim 13 wherein the plurality of energy discriminating detectors are fabricated from high-Z semiconductor materials including cadmium-telluride (CdTe), cadmium-zinc-telluride (CZT), mercury iodide (HgI₂), selenium (Se), lead iodide (PbI₂), gallium arsenide (GaAs).

17. The system of claim 13 wherein the said object is a liquid, aerosol, gel (LAG) item.

18. The system of claim 13 further comprising a processor for receiving output signals from said plurality of detectors and overlaying said output signals onto a visual image of the said receptacle and object.