X-ray inspection using spatially and spectrally tailored beams

• US 7,010,094 B2
• Filed: 05/31/2002
• Issued: 03/07/2006
• Est. Priority Date: 02/10/2000
• Status: Expired due to Fees

• Current Assignee: American Science and Engineering Incorporated (OSI Systems Incorporated)
• Original Assignee: American Science and Engineering Incorporated (OSI Systems Incorporated)
• Inventors: Grodzins, Lee, Rothschild, Peter, Swift, Roderick D.
• Primary Examiner(s): Glick, Edward J.
• Assistant Examiner(s): Kiknadze, Irakli
• Application Number:
  US10/161,037
• Publication Number:
  US 20030016790A1
• Time in Patent Office: 1,376 Days
• Field of Search: 378/57, 378/58, 378/147, 378/156, 378/157, 378/160, 378/145, 378/146, 378/148, 378/150, 378/158, 378/19, 378/98.8, 250/358.1
• US Class Current: 378/157
• CPC Class Codes: G01N 23/02 by transmitting the radiation through the material
• CPC Class Codes: G01N 23/04 and forming images of the material
• 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
• CPC Class Codes: G01V 5/224 Multiple energy techniques using one type of radiation, e.g. X-rays of different energies
• CPC Class Codes: G21K 5/10 with provision for relative movement of beam source and object to be irradiated

Abstract

A system and method for inspecting an object, the system and method comprising a source for generating a penetrating radiation beam for irradiating the object, the beam having, for each instant of time, an instantaneous energy spectrum of intensity, a shaper for modulating the generated beam, thereby creating a shaped beam, the shaper comprising at least a first section and a second section, the first section attenuating the intensity of a portion of the generated beam by a first attenuation factor and the second section attenuating the intensity of another portion of the generated beam by a second attenuation factor, and at least one detector for detecting the shaped beam after the shaped beam interacts with the object. The source may scan a beam across an object while the source and at least one detector are moving on a platform capable of highway travel or on an inspection module movable with respect to the object.

Claims

1. A graduated collimating aperture for providing a beam of increasing average energy as a function of distance measured from a central axis, the collimating aperture comprising a plurality of concentric areas, each of the areas defined in a plane substantially perpendicular to the central axis, such that any specified area is characterized by an opacity to the beam exceeding that of any area interior to the specified area.

2. The graduated collimating aperture according to claim 1, wherein at least one of the plurality of concentric areas is the surface of an x-ray attenuating material.

3. The graduated collimating aperture according to claim 1, wherein the plurality of concentric areas includes a central area of substantially no attenuation.

4. The graduated collimating aperture according to claim 1, wherein a subset of the plurality of concentric areas comprise, surfaces of frames of radially increasing opacity.

5. An inspection system for inspecting an object, the system comprising:

a. a source for generating a penetrating radiation beam for irradiating the object, the beam having, at each instant of time, an instantaneous power spectrum of intensity as a function of energy;

b. a shaper for modulating the generated beam, thereby creating a shaped beam, the shaper comprising at least a first section and a second section, the first section attenuating the intensity of a portion of the generated beam by a first attenuation factor and the second section attenuating the intensity of another portion of the generated beam by a second attenuation factor;

c. a scanner for scanning the first and second sections of the penetrating radiation beam with respect to the inspected object and

d. at least one detector for detecting the shaped beam after the shaped beam interacts with the object

wherein the shaper spatially separates the shaped beam into a first beam and a second beam, the first beam including the portion of the generated beam attenuated in the first section of the shaper and the second beam including the portion of the generated beam attenuated in the second section of the shaper.

6. The inspection system according to claim 5, wherein the at least one detector detects the first beam after the first beam interacts with the object, further comprising a second detector for detecting the second beam after the second beam interacts with the object.

7. The inspection system according to claim 6, wherein the at least one detector further detects photons of energies in the first beam exceeding a first fiducial energy and wherein the second detector further detects photons of energies in the second beam exceeding a second fiducial energy.