Radiation source position detection method, radiation source position detection system and radiation source position detection probe

• US 20040037394A1
• Filed: 05/20/2003
• Published: 02/26/2004
• Est. Priority Date: 05/20/2002
• Status: Active Grant

• Current Assignee: Japan Aerospace Exploration Agency, Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Japan Aerospace Exploration Agency, Mitsubishi Heavy Industries, Ltd.
• Inventors: Watanabe, Shin, Kuroda, Yoshikatsu, Takahashi, Tadayuki, Masuko, Ryouchi
• Granted Patent: US 6,862,087 B2
• Time in Patent Office: Days
• US Class Current: 378/205
• CPC Class Codes: A61B 2090/392 Radioactive markers
• CPC Class Codes: A61B 6/4429 related to the mounting of source units and detector units
• CPC Class Codes: A61B 6/547 involving tracking of position of the device or parts of the device
• CPC Class Codes: A61B 6/583 using calibration phantoms
• CPC Class Codes: G01T 1/169 Exploration, location of contaminated surface areas
• CPC Class Codes: G01T 1/2907 Angle determination; Directional detectors; Telescopes prospecting by the use of nuclear radiation, e.g. of natural or induced radioactivity G01V5/00

Abstract

A radiation source position detection system is provided, wherein three radiation detectors are arranged at different positions. Based on radiations incident to each of the radiation detectors, curved surfaces where a radiation source exists are calculated. By solving equations of each of the curved surfaces simultaneously, the position of the radiation source is detected.

Claims

1. A method of detecting a radiation source position, comprising:

detecting a radiation from a radiation source at three or more different detection positions;

estimating at least three curved surfaces where the radiation source exists, based on the radiation detected at each of the detection positions; and

acquiring the position of the radiation source based on said each estimated curved surface.

2. A method of detecting a radiation source position according to claim 1,

wherein the radiation is detected by two detection plates arranged in predetermined spaced relation with each other, and said each curved surface is estimated based on the spaced relation and the number of radiations incident to said each detection plate.

3. A method of detecting a radiation source position, comprising:

detecting a radiation from a radiation source at three or more different detection positions;

estimating at least three curved surfaces where the radiation source exists, based on the radiation detected along each incident direction; and

acquiring the position of the radiation source based on said each estimated curved surface.

4. A method of detecting a radiation source position according to claim 3,

wherein the radiation is detected by two detection plates arranged in predetermined spaced relation with each other, and said each curved surface is estimated based on the spaced relation and the number of radiations incident to said each detection plate.

5. A radiation source position detection system comprising:

at least three radiation detectors which are arranged at different positions and detect the incident radiations, respectively;

estimation units which estimate a curved surface where the radiation source exists, based on the radiation detected by said each radiation detector; and

position acquisition units which detect the position of the radiation source, based on each curved surface estimated by each of the estimation units.

6. A radiation source position detection system according to claim 5,

wherein said each radiation detector includes two detection plates which are arranged in predetermined spaced relation with each other and with which the incident radiation is detected, and

said each estimation unit includes an incident ray number detection unit which detects the number of radiations incident to each detection plate;

and a curved surface calculation unit which calculates a curved surface where the radiation source exists, based on the number of the radiations incident to said each detection plate and the distance of the predetermined space.

7. A radiation source position detection system according to claim 6, wherein said each detection plate is composed of a semiconductor or a scintillator.

8. A radiation source position detection system comprising:

radiation detectors which detects an incident radiation along different first, second and third directions, respectively;

estimation units which estimate a first curved surface, a second curved surface and a third curved surface where the radiation source exists, based on each radiation detected along the first, second and third directions, respectively; and

position acquisition units which acquire the position of the radiation source based on each of the curved surfaces estimated by each of the estimation units.

9. A radiation source position detection system according to claim 8;

wherein the radiation detectors each includes a first layer having a first detection plate; and

a second layer arranged in predetermined spaced relation in a front or subsequent stage of the first layer and having second, third and fourth detection plates, the radiation incident from the first direction is detected by a first detection unit comprising the first detection plate and the second detection plate, the radiation incident from the second direction is detected by a second detection unit comprising the first detection plate and the third detection plate, and the radiation incident from the third direction is detected by a third detection unit comprising the first detection plate and the fourth detection plate, and

said each estimation unit detects the number of radiations incident to each detection plate;

estimates the first curved surface where the radiation source exists, based on the number of the radiations incident to said each detection plate configuring the first detection unit and the distance between the first detection plate and the second detection plate;

estimates the second curved surface where the radiation source exists, based on the number of the radiations incident to said each detection plate configuring the second detection unit and the distance between the first detection plate and the third detection plate; and

estimates the third curved surface where the radiation source exists, based on the number of the radiations incident to said each detection plate configuring the third detection unit and the distance between the first detection plate and the fourth detection plate.

10. A radiation source position detection system according to claim 9, wherein each of the first to fourth detection plates is composed of a semiconductor or a scintillator.

11. A radiation source position detection system according to claim 8;

wherein the radiation detectors each includes;

a first detection plate;

a second detection plate arranged in a first spaced relation with the first detection; and

a third detection plate arranged in a second spaced relation with the first detection plate and having a center axis different from that of the first detection plate and the second detection plate, the radiation ray incident from the first direction is detected by a first detection unit comprising the first detection plate and the second detection plate, the radiation ray incident from the second direction is detected by a second detection unit comprising the first detection plate and the third detection plate, and the radiation ray incident from the third direction is detected by a third detection unit comprising the second detection plate and the third detection plate, and

said estimation unit detects the number of radiations incident to each detection plate;

estimates the first curved surface where the radiation source exists, based on the number of the radiations incident to said each detection plate configuring the first detection unit and the distance between the first detection plate and the second detection plate;

estimates the second curved surface where the radiation source exists, based on the number of the radiations incident to said each detection plate configuring the second detection unit and the distance between the first detection plate and the third detection plate; and

estimates the third curved surface where the radiation source exists, based on the number of the radiations incident to said each detection plate configuring the third detection unit and the distance between the second detection plate and the third detection plate.

12. A radiation source position detection system according to claim 11, wherein each of the first to third detection plates is composed of a semiconductor or scintillator.

13. A radiation detection probe for detecting incident radiations along different first, second and third directions, comprising:

a first layer having a first detection plate; and

a second layer arranged in a predetermined spaced relation in a front or subsequent stages of the first layer and having second, third and fourth detection plates,

wherein the incident radiations are detected along the first direction by a first detection unit comprising the first detection plate and the second detection plate, along the second direction by a second detection unit comprising the first detection plate and the third detection plate, and along the third direction by a third detection unit comprising the first detection plate and the fourth detection plate, respectively.

14. A radiation detection probe according to claim 13, wherein each of the first to fourth detection plates is composed of a semiconductor or a scintillator.

15. A radiation detection probe for detecting incident radiations along different first, second and third directions, comprising:

a first detection plate;

a second detection plate arranged in a first spaced relation with the first detection plate; and

a third detection plate arranged in a second spaced relation with the first detection plate and having a shape or a center axis different from that of the first detection plate and the second detection plate,

wherein the incident radiations are detected along the first direction by a first detection unit comprising the first detection plate and the second detection plate, along the second direction by a second detection unit comprising the first detection plate and the third detection plate, and along the third direction by a third detection unit comprising the second detection plate and the third detection plate, respectively.

16. A radiation source position detection probe according to claim 15, wherein each of the first to third detection plates is composed of a semiconductor and a scintillator.