Combined scatter and transmission multi-view imaging system

• US 9,057,679 B2
• Filed: 01/31/2013
• Issued: 06/16/2015
• Est. Priority Date: 02/03/2012
• Status: Active Grant

• Current Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Original Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Inventors: Morton, Edward James
• Primary Examiner(s): Midkiff, Anastasia
• Application Number:
  US13/756,211
• Publication Number:
  US 20140044233A1
• Time in Patent Office: 866 Days
• Field of Search: 378/57, 378/62, 378 86- 92, 378/95, 378/98.8, 378/119, 378/121, 378/146, 378/147, 378149-151, 378/204, 378/210, 250/370.01, 250/370.08, 250/370.09, 250/370.1, 250/370.11, 250/370.12, 250/370.13, 250/370.14, 250/374, 250/382, 250/487.1
• US Class Current: 1/1
• CPC Class Codes: G01N 2201/10 Scanning
• CPC Class Codes: G01N 2201/1047 with rotating optics and moving stage
• CPC Class Codes: G01N 23/04 and forming images of the material
• CPC Class Codes: G01N 23/20008 Constructional details of analysers, e.g. characterised by X-ray source, detector or optical system; Accessories therefor; Preparing specimens therefor monochromators for X- rays using crystals G21K1/06
• CPC Class Codes: G01N 23/20083 by using a combination of at least two measurements at least one being a transmission measurement and one a scatter measurement
• CPC Class Codes: G01V 5/20 Detecting prohibited goods, e.g. weapons, explosives, hazardous substances, contraband or smuggled objects
• 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 5/223 Mixed interrogation beams, e.g. using more than one type of radiation beam
• CPC Class Codes: G01V 5/232 having relative motion between the source, detector and object other than by conveyor G01V5/226 takes precedence
• CPC Class Codes: G01V 5/26 Passive interrogation, i.e. by measuring radiation emitted by objects or goods
• CPC Class Codes: G21K 1/043 changing time structure of beams by mechanical means, e.g. choppers, spinning filter wheels
• CPC Class Codes: H05G 1/70 Circuit arrangements for X-ray tubes with more than one anode; Circuit arrangements for apparatus comprising more than one X ray tube or more than one cathode H05G1/58 takes precedence

Abstract

The present specification discloses a multi-view X-ray inspection system having, in one of several embodiments, a three-view configuration with three X-ray sources. Each X-ray source rotates and is configured to emit a rotating X-ray pencil beam and at least two detector arrays, where each detector array has multiple non-pixellated detectors such that at least a portion of the non-pixellated detectors are oriented toward both the two X-ray sources.

Claims

1. An X-ray inspection system for scanning an object, the inspection system comprising:

a first X-ray source and a second X-ray source, each configured to simultaneously emit rotating X-ray beams for irradiating the object, wherein each of said X-ray beams defines a transmission path;

a detector array comprising at least one transmission detector placed between at least two backscatter detectors, wherein each of said backscatter detectors detects backscattered X-rays emitted by the first X-ray source placed on a first side of the object and wherein the transmission detectors detects transmitted X-rays emitted by the second X-ray source placed on an opposing side of the object; and

at least one controller for controlling each of the first and second X-ray sources to concurrently scan the object in a coordinated, non-overlapping, manner such that the transmission paths of each of said X-ray beams does not cross.

2. The X-ray inspection system as claimed in claim 1 wherein the detector array comprises at least two rectangular profile backscatter detectors and a square profile transmission detector positioned between said at least two rectangular profile backscatter detectors.

3. The X-ray inspection system as claimed in claim 1 wherein the detector array comprises a transmission detector positioned between two backscatter detectors and wherein the detectors are placed within a single plane facing the object begin scanned and the transmission detector has a smaller exposed surface area than each of the backscatter detectors.

4. The X-ray inspection system as claimed in claim 1 further comprising a pair of fixed collimators positioned between the transmission detector and one of said at least two backscatter detectors.

5. The X-ray inspection system as claimed in claim 1 wherein each of the X-ray sources comprises an extended anode X-ray tube, a rotating collimator assembly, a bearing, a drive motor, and a rotary encoder.

6. The X-ray inspection system as claimed in claim 1 wherein each of the first and second X-ray sources comprises:

an extended anode X-ray tube coupled with a cooling circuit, the anode being at ground potential;

a rotating collimator assembly comprising at least one collimating ring with slots cut at predefined angles around a circumference of the collimator, a length of each slot being greater than a width and an axis of rotation of the slot, and the width of the slots defining an intrinsic spatial resolution of the X-ray inspection system in a direction of the scanning;

a bearing for supporting a weight of the collimator assembly and transferring a drive shaft from the collimator assembly to a drive motor;

a rotary encoder for determining an absolute angle of rotation of the X-ray beams; and

a secondary collimator set for improving spatial resolution in a perpendicular scanning direction.

7. The X-ray inspection system as claimed in claim 6 wherein the controller receives speed data comprising a speed of the object and, based upon said speed data, adjusts at least one of a collimator rotation speed of an X-ray source, a data acquisition rate, or an X-ray tube current based upon said speed data.