Method, apparatus and system for inspecting object based on cosmic ray

Patent metadata

Field	Value
Publication number	US-10613247-B2
Application number	US-201715411348-A
Country	US
Kind code	B2
Filing date	Jan 20, 2017
Priority date	Jan 22, 2016
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

The present application relates to a method, apparatus and system for inspecting an object based on a cosmic ray, pertaining to the technical field of radiometric imaging and safety inspection. The method includes: recording a movement trajectory of an inspected object by using a monitoring device; acquiring information of charged particles in the cosmic ray by using a position-sensitive detector, the information of charged particles comprising trajectory information of the charged particles; performing position coincidence for the movement trajectory and the trajectory information to determine the object; performing trajectory remodeling for the charged particles according to the information of charged particles; and identifying a material inside the moving object according to the trajectory remodeling. According to the present disclosure, pedestrians who are walking and moving are inspected by using the cosmic ray, and nuclear materials, drugs and explosive materials and the like carried by human bodies may be detected.

First claim

The invention claimed is:

1. A method for inspecting an object based on a cosmic ray, comprising:
recording a movement trajectory of an inspected object by using a monitoring device, wherein the monitoring device comprises a plurality of depth camera covering a passageway for detecting and tracking the movement trajectory of the inspected object;
acquiring information of charged particles in the cosmic ray by using a position-sensitive detector, the information of charged particles comprising trajectory information of the charged particles, wherein the information of the charged particles is updated in real time;
performing position coincidence for information of the movement trajectory obtained from the plurality of depth cameras and the trajectory information of the charged particles to determine the object;
performing trajectory remodeling for the charged particles according to the information of charged particles, wherein the performing trajectory remodeling for the charged particles according to the information of charged particles comprises:
calculating a Ratio parameter of an material according to the trajectory information of the charged particles, and estimating an initial atomic number and an initial relative mass number of the material, the Ratio parameter being a ratio between a scattering parameter and a stopping parameter that are exerted by the material on the charged particles;
calculating a radiation length according to a relationship between the initial atomic number and the radiation length and a relationship between the initial relative mass number and the radiation length;
acquiring a thickness of the material according to the radiation length;
calculating the stopping parameter and the scattering parameter of the material according to the initial atomic number, the initial relative mass number and the thickness of the material; and
identifying the material according to the stopping parameter and the scattering parameter, wherein low atomic number materials are identified by using a stopping effect of electrons in the charged particles, and medium to high atomic number materials are identified by using a scattering effect of muons in the charged particles; and

identifying a material inside the moving object according to the trajectory remodeling.

2. The method according to claim 1 , wherein the position-sensitive detector is configured to have the capability of detecting the charged particles of the cosmic ray.

3. The method according to claim 2 , wherein the position-sensitive detector is configured to have the capability of detecting medium to high atomic number materials whose atomic number is greater than that of aluminum, and low atomic number materials whose atomic number is lower than that of aluminum; wherein
the low atomic number materials are identified by using a stopping effect of electrons; and
the medium to high atomic number materials are identified by using a scattering effect of muons.

4. The method according to claim 1 , wherein the position-sensitive detector comprises a GEM detector, an MRPC detector, a drift chamber or a drift tube array.

5. The method according to claim 1 , wherein the position-sensitive detector is configured to act as a portion of a pedestrian inspection system, and the position-sensitive detector is disposed in an inspection passage, wherein an inspected pedestrian passes through the position-sensitive detector.

6. The method according to claim 1 , further comprising: reconstructing a material distribution diagram by using an imaging algorithm according to a corresponding relationship between the stopping parameter, the scattering parameter and material properties, wherein the imaging algorithm comprises PoCA algorithm and/or MLSD-OSEM algorithm.

7. The method according to claim 1 , further comprising: updating material information to perform a next iteration.

8. The method according to claim 1 , further comprising: determining a category characteristic of the material of the moving object according to a corresponding relationship between the stopping parameter, the scattering parameter and material properties, and identifying the material according to a non-parameter inspection method.

9. The method according to claim 1 , wherein in the trajectory remodeling, a plurality of pieces of trajectory information of the charged particles are parallelly processed.

10. The method according to claim 1 , wherein the trajectory information of the charged particles comprises time of incidence, position of incidence, direction of incidence, time of emergence, position of emergence and direction of emergence of the charged particles.

11. The method according to claim 10 , wherein the performing position coincidence for the movement trajectory and the trajectory information to determine the object comprises:
performing a time difference analysis on the time of incidence and the time of emergence; and
coinciding the trajectory information of the charged particles with the time and position of the movement trajectory of the object according to the position of incidence, the position of emergence and the time different analysis.

12. An apparatus for inspecting an object based on a cosmic ray, comprising:
a processor;
a memory for storing instructions executable by the processor;
wherein the processor is configured to:
record a movement trajectory of an inspected object by using a monitoring device;
acquire information of charged particles in the cosmic ray by using a position-sensitive detector, the information of charged particles comprising trajectory information of the charged particles, wherein the information of the charged particles is updated in real time;
perform position coincidence for the movement trajectory and the trajectory information to determine the object;
perform trajectory remodeling for the charged particles according to the information of charged particles, wherein in performing the trajectory remodeling for the charged particles according to the information of charged particles, the processor is configured to:
calculate a Ratio parameter of a material according to the trajectory information of the charged particles and estimate an initial atomic number and an initial relative mass number of the material, the Ratio parameter being a ratio between a scattering parameter and a stopping parameter that are exerted by the material on the charged particles;
calculate a radiation length according to a relationship between the initial atomic number and the radiation length and a relationship between the initial relative mass number and the radiation length;
acquire a thickness of the material according to the radiation length; and
calculate the stopping parameter and the scattering parameter of the material according to the initial atomic number, the initial relative mass number and the thickness of the material, and identify the material according to the stopping parameter and the scattering parameter, wherein low atomic number materials are identified by using a stopping effect of electrons in the charged particles, and medium to high atomic number materials are identified by using a scattering effect of muons in the charged particles; and

identify a material inside the moving object according to the trajectory remodeling,
wherein the monitoring device comprises a plurality of depth camera covering a passageway for detecting and tracking the movement trajectory of the inspected object, and the movement trajectory is obtained from the plurality of depth cameras.

13. A system for inspecting an object based on a cosmic ray, comprising:
a monitoring device, configured to re

Assignees

• Univ Tsinghua
• Nuctech Co Ltd

Inventors

• Kang Kejun
• Chen Zhiqiang
• Li Yuanjing
• Zhao Ziran
• Li Junli
• Wang Xuewu
• Liu Yaohong
• Zeng Zhi
• Gu Jianping
• Liang Song
• Liu Bicheng
• Xu Guangming
• Wang Yongqiang

Classifications

• G01T5/02

  Processing of tracks; Analysis of tracks · CPC title

• G01N2223/205

  natural source · CPC title

• G01T1/167

  Measuring radioactive content of objects, e.g. contamination (whole body counters G01T1/163) · CPC title

• G01T5/002

  using a combination of several movement of track recording devices · CPC title

• G01V5/0091

  Physics · mapped topic