Multiple Screen Detection Systems

• US 20090141860A1
• Filed: 10/31/2008
• Published: 06/04/2009
• Est. Priority Date: 11/01/2007
• Status: Active Grant

• Current Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Original Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Inventors: Hughes, Ronald J., Gray, Steven J., Ryge, Peter
• Granted Patent: US 8,003,949 B2
• Time in Patent Office: Days
• US Class Current: 378/62
• CPC Class Codes: G01T 1/167 Measuring radioactive content of objects, e.g. contamination whole body counters G01T1/163
• CPC Class Codes: G01T 1/2008 using a combination of different types of scintillation detectors, e.g. phoswich

Abstract

The present invention is a detection system and method for using the detection system in radiant energy imaging systems. In particular, the present invention is an improved detection system employing multiple screens for greater detection efficiency. And more particularly, the present invention is a detection system for detecting electromagnetic radiation having an enclosure having four adjacent walls, connected to each other at an angle and forming a rectangle and interior portion of the enclosure, a front side area and a back side area formed from the four adjacent walls and located at each end of the enclosure, at least two screens, that further include an active area for receiving and converting electromagnetic radiation into light, and a photodetector, positioned in the interior portion of the enclosure, having an active area responsive to the light.

Claims

1. A detection system for detecting electromagnetic radiation comprising:

an enclosure having four adjacent walls, connected to each other at an angle and forming a rectangle and interior portion of the enclosure;

a front side area and a back side area formed from the four adjacent walls and located at each end of the enclosure;

at least two screens, wherein each screen further comprises an active area for receiving and converting electromagnetic radiation into light; and

a photodetector, positioned in the interior portion of the enclosure, having an active area responsive to the light.

2. The detection system of claim 1 wherein the enclosure formed from the adjacent walls, front side area, and back side area receives and does not leak electromagnetic radiation.

3. The detection system of claim 1 wherein the interior surface of the adjacent enclosing walls is light reflective.

4. The detection system of claim 1 wherein the front side area is formed from at least one of the plurality of screens.

5. The detection system of claim 1 wherein the active area on each of the plurality of screens comprises a scintillator material.

6. The detection system of claim 4 wherein the scintillator material is calcium tungstate.

7. The detection system of claim 1 wherein the active area of at least one of the plurality of screens is larger than the active area of the photodetector.

8. The detection system of claim 1 wherein the areal density of at least one of the plurality of screens is 80 mg/cm².

9. The detection system of claim 1 wherein the surface geometry of at least one of the plurality of screens is straight or smooth.

10. The detection system of claim 1 wherein the surface geometry of at least one of the plurality of screens is irregular.

11. The detection system of claim 1 wherein the surface geometry of at least one of the plurality of screens is contoured.

12. The detection system of claim 1 wherein the surface geometry of at least one of the plurality of screens is corrugated.

13. The detection system of claim 1 wherein the photodetector is a photomultiplier tube.

14. A radiant energy imaging system comprising:

a radiation source;

a detection system, comprising i) an enclosure having four adjacent walls, connected to each other at an angle and forming a rectangle and interior portion of the enclosure;

ii) a front side area and a back side area formed from the four adjacent walls and located at each end of the enclosure;

iii) at least two screens, wherein each screen further comprises an active area for receiving and converting electromagnetic radiation into light; and

iv) a photodetector, positioned in the interior of the enclosure, having an active area responsive to the light;

an image processor for receiving signals from the photodetector and generating an image; and

a display for displaying the image generated.

15. The radiant energy imaging system of claim 14 wherein the system is a people screening system.

16. The radiant energy imaging system of claim 14 wherein the system is a baggage screening system.

17. A detection system for detecting electromagnetic radiation comprising:

an enclosure having four adjacent walls, connected to each other at an angle and forming a rectangle and interior portion of the enclosure;

a front side area and a back side area formed from the four adjacent walls and located at each end of the enclosure;

a screen located in the front side area, further comprising an active area for receiving and converting electromagnetic radiation into light;

at least one screen located in the interior portion of the enclosure; and

a photodetector, positioned in the interior of the enclosure, having an active area responsive to the light.