Backscatter inspection systems, and related methods

• US 9,851,312 B2
• Filed: 05/07/2014
• Issued: 12/26/2017
• Est. Priority Date: 05/07/2014
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Edwards, William Talion, Georgeson, Gary, Engel, James E., Safai, Morteza
• Primary Examiner(s): Fox, Dani
• Application Number:
  US14/272,177
• Publication Number:
  US 20150323477A1
• Time in Patent Office: 1,329 Days
• CPC Class Codes: G01N 2223/313 filters, rotating filter disc
• CPC Class Codes: G01N 23/203 Measuring back scattering
• CPC Class Codes: G21K 1/10 Scattering devices; Absorbing devices; Ionising radiation filters

Abstract

Inspection systems employing radiation filters with different attenuation characteristics to determine specimen irregularities, and related methods are disclosed. An inspection system includes a radiation emitter configured to emit a radiation beam along a radiation trajectory. Some of the radiation may be reflected by the specimen as backscatter and received by at least one radiation detector of the inspection system along the radiation trajectory. Irregularities and various materials of the specimen may produce backscatter radiation at different energies and/or scatter angles which may be identified by employing radiation filters having different attenuation characteristics. By employing these filters in communication with the radiation emitter and the radiation detector, the backscatter radiation passed through the filters may be measured and integrated at different positions of the radiation beam to produce a composite image of the specimen. In this manner, irregularities and associated materials within the specimen may be more easily identified.

Claims

1. An inspection system, comprising:

a radiation scanner configured to emit a radiation beam along a radiation trajectory;

a plurality of filters comprising at least two filters selectably positionable so that at least one of the at least two filters receives at least a portion of the radiation of the radiation beam backscattered from a specimen and passes attenuated radiation, wherein the at least two filters respectively have different attenuation characteristics;

a radiation detector configured to receive the attenuated radiation and configured to produce detection data associated with an energy intensity of the attenuated radiation; and

a rendering system configured to create a composite image of the specimen disposed along the radiation trajectory using the detection data from the attenuated radiation passed through the at least two filters.

2. The system of claim 1, wherein the plurality of filters are movable with respect to the radiation detector to enable selectable ones of the at least two filters to pass attenuated radiation to the radiation detector.

3. The system of claim 2, wherein in a first arrangement of at least two arrangements the radiation detector is configured to exclusively receive the attenuated radiation from a first filter of the at least two filters.

4. The system of claim 3, wherein in a second arrangement of the at least two arrangements the radiation detector is configured to exclusively receive the attenuated radiation from a second filter of the at least two filters.

5. The system of claim 1, wherein a first filter of the at least two filters comprises aluminum of a thickness less than one millimeter, and a second filter of the at least two filters comprises aluminum of a thickness greater than the thickness of the first filter.

6. The system of claim 2, wherein the at least two filters are selectively positionable in a portion of the radiation trajectory to receive the at least the portion of the radiation backscattered from the specimen.

7. The system of claim 1, wherein the plurality of filters include layered filters which are arranged so that a first radiation detector of the radiation detector receives attenuated radiation solely from a first layered filter of the layered filters, and a second radiation detector of the radiation detector receives attenuated radiation passed through the first layered filter and a second layered filter of the layered filters.

8. The system of claim 1, further comprising a track stage to move the radiation scanner relative to the specimen.

9. The system of claim 1, wherein the plurality of filters are included as part of at least one movable filter mount.

10. A method of inspecting a specimen, comprising:

emitting a radiation beam from a radiation scanner of a backscatter inspection system into a radiation trajectory;

selectively positioning at least two filters of a plurality of filters of the backscatter inspection system so that at least one of the at least two filters receives at least a portion of the radiation of the radiation beam backscattered from the specimen and passes attenuated radiation, wherein the at least two filters respectively have different attenuation characteristics;

receiving the attenuated radiation with a radiation detector of the backscatter inspection system and producing detection data associated with an energy intensity of the attenuated radiation; and

creating a composite image of the specimen with a rendering system of the backscatter inspection system using the detection data produced from the attenuated radiation passed through the at least two filters.

11. The method of claim 10, wherein the selectively positioning comprises moving the at least two filters with respect to the radiation detector to enable selectable ones of the at least two filters to pass attenuated radiation to the radiation detector while the at least two filters are respectively disposed in at least two arrangements.

12. The method of claim 11, wherein the receiving the attenuated radiation comprises the radiation detector exclusively receiving the attenuated radiation from a first filter of the at least two filters in a first arrangement of the at least two arrangements.

13. The method of claim 12, wherein the receiving the attenuated radiation comprises the radiation detector exclusively receiving the attenuated radiation from a second filter of the at least two filters in a second arrangement of the at least two arrangements.

14. A non-transitory computer-readable storage medium containing computer-readable program code that, when executed by operation of one or more computer processors, performs an operation comprising:

instructing a radiation scanner of a backscatter inspection system to emit a radiation beam and along a radiation trajectory;

selectively positioning at least two filters of a plurality of filters of the backscatter inspection system so that at least one of the at least two filters receives at least a portion of the radiation of the radiation beam backscattered from a specimen and passes attenuated radiation, wherein the at least two filters respectively have different attenuation characteristics;

receiving detection data produced from a radiation detector of the backscatter inspection system, the radiation detector producing the detection data based on an energy intensity of the attenuated radiation received by the radiation detector; and

rendering a composite image of the specimen at a rendering system of the backscatter inspection system using the detection data passed through the at least two filters.

15. The computer-readable storage medium of claim 14, wherein the computer-readable program code, when executed by operation of the one or more computer processors, performs further operations comprising:

instructing a movement of the at least two filters with respect to the radiation detector to enable selectable ones of the at least two filters to pass attenuated radiation to the radiation detector while the at least two filters are respectively disposed in at least two arrangements.

16. The computer-readable storage medium of claim 15, wherein the computer-readable program code, when executed by operation of the one or more computer processors, performs further operations comprising:

instructing a movement of the at least two filters to a first arrangement of the at least two arrangements wherein in the first arrangement the radiation detector exclusively receives the attenuated radiation from a first filter of the at least two filters.

17. The computer-readable storage medium of claim 16, wherein the computer-readable program code, when executed by operation of the one or more computer processors, performs further operations comprising:

instructing a movement of the at least two filters to a second arrangement of the at least two arrangements wherein in the second arrangement the radiation detector exclusively receives the attenuated radiation from a second filter of the at least two filters.

18. The computer-readable storage medium of claim 14, wherein the computer-readable program code, when executed by operation of the one or more computer processors, performs further operations comprising:

instructing a movement of the radiation scanner in a direction angled to the radiation beam.