阅读说明：本技术 双模探测方法、控制器和系统 (Dual-mode detection method, controller and system ) 是由 杨祎罡 王学武 张智 李元景 李荐民 于 2018-07-11 设计创作，主要内容包括：本公开提出一种双模探测方法、控制器和系统,涉及射线检测技术领域。本公开的一种双模探测方法包括：根据X射线物体探测数据、X射线无物体探测数据、中子物体探测数据和中子无物体探测数据,确定被测物体对于中子和X射线的微分截面的比值；根据被测物体对于X射线和中子的微分截面的比值与物质类型的对应关系识别物质类型。通过这样的方法,能够实现利用中子和X射线对被测物体的双能探测,利用物质对于中子和X射线的不同的衰减能力得到核素类型,实现识别元素种类,提高探测的精确度。(The disclosure provides a dual-mode detection method, a controller and a system, and relates to the technical field of ray detection. The dual-mode detection method comprises the following steps: determining the ratio of the differential cross section of the measured object to neutrons and X rays according to the X-ray object detection data, the X-ray no-object detection data, the neutron object detection data and the neutron no-object detection data; and identifying the type of the substance according to the corresponding relation between the ratio of the differential cross section of the measured object to the X-ray and the neutron and the type of the substance. By the method, the dual-energy detection of the neutron and the X-ray to the object to be detected can be realized, the nuclide type can be obtained by utilizing different attenuation capacities of the substance to the neutron and the X-ray, the element type can be identified, and the detection accuracy is improved.)

1. A dual mode detection method, comprising:

determining the ratio of the differential cross section of the object to be measured to neutrons and X rays according to X-ray object detection data, X-ray no-object detection data, neutron object detection data and neutron no-object detection data;

and identifying the type of the substance according to the corresponding relation between the ratio of the differential cross section of the measured object to the X-ray and the neutron and the type of the substance.

2. The method of claim 1, wherein,

when an object to be detected is placed between a first detection port of the dual-mode detection device and the X-ray detector, acquiring detection data of the X-ray object according to a detection result of the X-ray detector, and acquiring neutron no-object detection data according to a detection result of the neutron detector;

when an object to be detected is placed between a second detection port of the dual-mode detection device and the neutron detector, acquiring the X-ray object-free detection data according to the detection result of the X-ray detector, and acquiring the neutron object detection data according to the detection result of the neutron detector;

wherein the first detection port emits X-rays and the second detection port emits neutron rays.

3. The method of claim 1 or 2, wherein the dual mode detection device emits electrons simultaneously to an X-ray conversion target and a neutron conversion target through a single electron accelerator, the X-ray conversion target generating X-rays that are emitted from the first detection port, the neutron conversion target generating neutron rays that are emitted from the second detection port.

4. The method of claim 1, wherein the determining a ratio of differential cross-sections of the object under test for neutrons and X-rays comprises:

determining the mass attenuation condition of the measured object to the neutrons according to the neutron object detection data and the neutron no-object detection data;

determining the mass attenuation condition of the object to be measured to the X ray according to the X ray object detection data and the X ray no-object detection data;

and determining the ratio of the differential cross section of the measured object to the neutrons and the X-rays according to the mass attenuation condition of the measured object to the neutrons and the mass attenuation condition of the measured object to the X-rays.

5. The method of claim 1, wherein the determining a ratio of differential cross-sections of the object under test for neutrons and X-rays comprises:

according to the formula

F(n)＝σ _n/σ _X＝(ln(I _n,0/I _n,D))/(ln(I _X,0/I _X,D))

Determining the ratio F (n) of the differential cross-sections of the measured object for neutrons n and X-rays, where σ _nIs the differential cross section, σ, of the object to be measured for neutrons _XIs the differential cross section of the measured object to X-rays, I _n,0For said neutron object-free detection data, I _n,DFor the neutron object detection data, I _X,0For the X-ray object-free detection data, I _X,DData is detected for the X-ray object.

6. The method of claim 1, further comprising:

and determining the relative content of various nuclides in the object to be measured according to the ratio of the differential cross sections of the object to be measured for neutrons and X-rays with different energies.

7. The method of claim 6, wherein the determining the relative content of the various nuclear species numbers in the object under test comprises:

according to the formula

Determining the relative content A of the number of various nuclides ₁～A _kWherein σ is _ni,jIs the differential cross-section of neutron n for the ith energy zone of the jth nuclide, σ _X,jIs a differential cross-section for the X-ray of the jth nuclide, F (n) _i) Is the ratio of the differential cross-section of the measured object for neutrons to X-rays in the i energy region, A _jI is more than or equal to 1 and less than or equal to m, j is more than or equal to 1 and less than or equal to k, and m is the number of neutron energy regionsThe quantity, k, is the number of species, and the number of energy regions is adjusted during the measurement so that m equals k.

8. The method of claim 1, further comprising: and imaging according to the ratio of the differential cross section of the measured object to the X-ray and the neutron.

9. A dual mode detection controller, comprising:

a ratio determination module configured to determine a ratio of differential cross sections of the object under test to neutrons and X-rays from X-ray object detection data, X-ray no-object detection data, neutron object detection data, and neutron no-object detection data;

a substance identification module configured to identify a substance type according to a ratio of differential cross sections of the object under test with respect to X-rays and neutrons.

10. The controller of claim 9, wherein the ratio determination module comprises:

the detection data acquisition unit is configured to acquire X-ray object detection data according to a detection result of an X-ray detector and acquire neutron no-object detection data according to a detection result of a neutron detector when the object to be detected is positioned at the first detection port; when the object to be detected is located at the second detection port, acquiring neutron object detection data according to the detection result of the neutron detector, and acquiring X-ray no-object detection data according to the detection result of the X-ray detector, wherein the first detection port emits X-rays, and the second detection port emits neutron rays;

a ratio operation unit configured to determine a ratio of differential cross sections of the object to be measured with respect to X-rays and neutrons from the X-ray object detection data, the X-ray no-object detection data, the neutron object detection data, and the neutron no-object detection data.

11. The controller of claim 10, wherein the ratio operation unit is configured to:

determining the mass attenuation condition of the measured object to the neutrons according to the neutron object detection data and the neutron no-object detection data;

determining the mass attenuation condition of the object to be measured to the X ray according to the X ray object detection data and the X ray no-object detection data;

determining the ratio of the differential cross section of the measured object to the neutrons and the X-rays according to the mass attenuation condition of the measured object to the neutrons and the mass attenuation condition of the measured object to the X-rays;

and determining the material type of the object to be measured according to the corresponding relation between the ratio of the differential cross sections of the neutrons and the X-rays of the material and the material type.

12. The controller of claim 10, wherein the ratio operation unit is configured to:

according to the formula

F(n)＝σ _n/σ _X＝(ln(I _n,0/I _n,D))/(ln(I _X,0/I _X,D))

Determining the ratio F (n) of the differential cross-sections of the object to be measured for neutrons and X-rays, where σ _nIs the differential cross section, σ, of the object to be measured for neutrons _XIs the differential cross section of the measured object to X-rays, I _n,0For said neutron object-free detection data, I _n,DFor the neutron object detection data, I _X,0For the X-ray object-free detection data, I _X,DData is detected for the X-ray object.

13. The controller of claim 9, wherein the substance identification module is further configured to:

and determining the relative content of various nuclides in the object to be measured according to the ratio of the differential cross sections of the object to be measured for neutrons and X-rays with different energies.

14. The controller of claim 13, wherein the determining the relative content of the various nuclear species numbers in the object under test comprises:

according to the formula

Determining the relative content A of the number of various nuclides ₁～A _kWherein σ is _ni,jIs the differential cross-section of neutrons for the ith energy region of the jth nuclide, σ _X,jIs a differential cross-section for the X-ray of the jth nuclide, F (n) _i) Is the ratio of the differential cross-section of the measured object for neutrons to X-rays in the i energy region, A _jI is more than or equal to 1 and less than or equal to m, j is more than or equal to 1 and less than or equal to k, m is the number of neutron energy regions, k is the number of nuclide species, and the number of energy regions is adjusted to make m equal to k in the measurement process.

15. The controller of claim 9, further comprising:

an imaging module configured to image according to a ratio of differential cross sections of the object under test for X-rays and neutrons.

16. A dual mode detection controller, comprising:

a memory; and

a processor coupled to the memory, the processor configured to perform the method of any of claims 1-8 based on instructions stored in the memory.

17. A computer readable storage medium having stored thereon computer program instructions which, when executed by a processor, implement the steps of the method of any one of claims 1 to 8.

18. A dual mode detection system, comprising:

the dual mode detection controller of any of claims 9-16; and the combination of (a) and (b),

a dual mode detection apparatus, comprising:

a single electron accelerator configured to emit electrons to the X-ray conversion target and the neutron conversion target simultaneously;

the X-ray conversion target is configured to generate X-rays under excitation of the electrons and emit from the first detection port;

the neutron conversion target generates neutron rays configured to generate neutrons upon excitation by the electrons and emits from the second detection port.

19. The system of claim 18, wherein the dual mode detection device comprises at least one of:

an X-ray chopper is arranged between the neutron conversion target and the second detection port;

an X-ray collimator is arranged between the X-ray conversion target and the first detection port; or the like, or, alternatively,

a neutron collimator is included between the neutron conversion target and the second detection port.

20. The system of claim 18 or 19, wherein a line connecting the first detection port and the X-ray conversion target is perpendicular to a line connecting the second detection port and the neutron-ray conversion target.

Technical Field

The disclosure relates to the technical field of ray detection, in particular to a dual-mode detection method, a controller and a system.

Background

Transmission imaging using X-rays generated by an electron accelerator is a conventional technique, which can obtain information on mass and thickness of a substance to be detected, but cannot identify the substance. In order to improve the ability to identify substances and even to enable analysis of isotope information, it is necessary to use two or more types of radiation.

Although some new X-ray imaging detection techniques, such as: the dual-energy X-ray, CT techniques, etc. have improved recognition capabilities, but have still been difficult to overcome the inherent disadvantages of being unable to recognize the element species.

Disclosure of Invention

One object of the present disclosure is to propose a solution for achieving substance class identification using neutron rays and X-rays.

According to an aspect of some embodiments of the present disclosure, a dual mode detection method is provided, including: determining the ratio of the differential cross section of the measured object to neutrons and X rays according to the X-ray object detection data, the X-ray no-object detection data, the neutron object detection data and the neutron no-object detection data; and identifying the type of the substance according to the corresponding relation between the ratio of the differential cross section of the measured object to the X-ray and the neutron and the type of the substance.

Optionally, when the object to be detected is placed between the first detection port of the dual-mode detection device and the X-ray detector, acquiring X-ray object detection data according to a detection result of the X-ray detector, and acquiring neutron object-free detection data according to a detection result of the neutron detector; when the object to be detected is placed between the second detection port of the dual-mode detection device and the neutron detector, acquiring X-ray object-free detection data according to the detection result of the X-ray detector, and acquiring neutron object detection data according to the detection result of the neutron detector; wherein the first detection port emits X-rays and the second detection port emits neutron rays.

Optionally, the dual-mode detection device emits electrons to the X-ray conversion target and the neutron conversion target synchronously through a single electron accelerator, the X-ray generated by the X-ray conversion target is emitted from the first detection port, and the neutron ray generated by the neutron conversion target is emitted from the second detection port.

Optionally, determining the ratio of the differential cross-sections of the object under test for neutrons and X-rays comprises: determining the mass attenuation condition of the measured object to the neutrons according to the neutron object detection data and the neutron non-object detection data; determining the mass attenuation condition of the detected object to the X ray according to the X ray object detection data and the X ray no-object detection data; and determining the ratio of the differential cross section of the measured object to the neutrons and the X-rays according to the mass attenuation condition of the measured object to the neutrons and the mass attenuation condition of the measured object to the X-rays.

Optionally, determining the ratio of the differential cross-sections of the object under test for neutrons and X-rays comprises: according to the formula

F(n)＝σ _n/σ _X＝ln(I _n,0/I _n,D)/ln(I _X,0/I _X,D)

Determining the ratio F (n) of the differential cross sections of the measured object for neutrons n and X-rays, where σ _nIs the differential cross section of the object to be measured, σ, for neutrons _XIs the differential cross section of the object to be measured with respect to X-rays, I _n,0For neutron non-object detection data, I _n,DFor neutron object detection data, I _X,0For X-ray object-free detection data, I _X,DData is detected for the X-ray object.

Optionally, the dual mode detection method further includes: and determining the relative contents of various nuclides in the object to be measured according to the ratio of the differential cross sections of the object to be measured for neutrons and X-rays with different energies.

Optionally, determining the relative content of the number of various nuclides in the object under test comprises: according to the formula

Determining the relative content A of the number of various nuclides ₁～A _kWherein σ is _ni,jIs the differential cross-section of neutron n for the ith energy zone of the jth nuclide, σ _X,jIs a differential cross-section for the X-ray of the jth nuclide, F (n) _i) Is the ratio of the differential cross-section of the measured object for neutrons to X-rays in the i energy region, A _jI is more than or equal to 1 and less than or equal to m, j is more than or equal to 1 and less than or equal to k, m is the number of neutron energy regions, k is the number of nuclide species, and the number of energy regions is adjusted to make m equal to k in the measurement process.

Optionally, the dual mode detection method further includes: imaging is performed according to the ratio of the differential cross-sections of the object to be measured for X-rays and neutrons.

By the method, detection data of X-rays and neutron rays in the states of being attenuated by a detected object and not being attenuated by the detected object can be respectively obtained, the specific value of the differential cross section of the detected object to neutrons and the X-rays is further obtained, the substance type of the detected object is determined according to the corresponding relation between the specific value of the differential cross section of different substances to the neutrons and the X-rays and the substance, so that dual-energy detection of the neutrons and the X-rays to the detected object is realized, the nuclide type is obtained by utilizing different attenuation capacities of the substance to the neutrons and the X-rays, the element type is identified, and the detection accuracy is improved.

According to another aspect of some embodiments of the present disclosure, there is provided a dual mode detection controller, comprising: a ratio determination module configured to determine a ratio of differential cross sections of the object under test to neutrons and X-rays from the X-ray object detection data, the X-ray no-object detection data, the neutron object detection data, and the neutron no-object detection data; and the substance identification module is configured to identify the substance type according to the ratio of the differential cross section of the measured object to the X-ray and the neutron.

Optionally, the ratio determining module comprises: the detection data acquisition unit is configured to acquire X-ray object detection data according to a detection result of the X-ray detector and acquire neutron no-object detection data according to a detection result of the neutron detector when the detected object is positioned at the first detection port; when the object to be detected is positioned at the second detection port, acquiring neutron object detection data according to the detection result of the neutron detector, and acquiring X-ray no-object detection data according to the detection result of the X-ray detector, wherein the first detection port emits X-rays, and the second detection port emits neutron rays; a ratio operation unit configured to determine a ratio of differential cross sections of the object to be measured with respect to the X-rays and the neutrons from the X-ray object detection data, the X-ray no-object detection data, the neutron object detection data, and the neutron no-object detection data.

Optionally, the ratio operation unit is configured to: determining the mass attenuation condition of the measured object to the neutrons according to the neutron object detection data and the neutron non-object detection data; determining the mass attenuation condition of the detected object to the X ray according to the X ray object detection data and the X ray no-object detection data; determining the ratio of differential cross sections of the measured object to the neutrons and the X-rays according to the mass attenuation condition of the measured object to the neutrons and the mass attenuation condition of the measured object to the X-rays; and determining the material type of the object to be measured according to the corresponding relation between the ratio of the differential cross sections of the neutrons and the X-rays of the material and the material type.

Optionally, the ratio operation unit is configured to: according to the formula

F(n)＝σ _n/σ _X＝ln(I _n,0/I _n,D)/ln(I _X,0/I _X,D)

Determining the ratio F (n) of the differential cross sections of the measured object for neutrons and X-rays, where σ _nIs the differential cross section of the object to be measured, σ, for neutrons _XIs the differential cross section of the object to be measured with respect to X-rays, I _n,0For neutron non-object detection data, I _n,DFor neutron object detection data, I _X,0For X-ray object-free detection data, I _X,DData is detected for the X-ray object.

Optionally, the substance identification module is further configured to: and determining the relative contents of various nuclides in the object to be measured according to the ratio of the differential cross sections of the object to be measured for neutrons and X-rays with different energies.

Optionally, determining the relative content of the number of various nuclides in the object under test comprises: according to the formula

Determining the relative content A of the number of various nuclides ₁～A _kWherein σ is _ni,jIs the differential cross-section of neutrons for the ith energy region of the jth nuclide, σ _X,jIs a differential cross-section for the X-ray of the jth nuclide, F (n) _i) Is the ratio of the differential cross-section of the measured object for neutrons to X-rays in the i energy region, A _jI is more than or equal to 1 and less than or equal to m, j is more than or equal to 1 and less than or equal to k, m is the number of neutron energy regions, k is the number of nuclide species, and the number of energy regions is adjusted to make m equal to k in the measurement process.

Optionally, the dual mode detection controller further comprises: an imaging module configured to image according to a ratio of differential cross sections of the object under test for X-rays and neutrons.

According to yet another aspect of some embodiments of the present disclosure, there is provided a dual mode detection controller, including: a memory; and a processor coupled to the memory, the processor configured to perform any of the dual mode detection methods as mentioned above based on instructions stored in the memory.

The dual-mode detection controller can respectively obtain detection data of X rays and neutron rays in the states of being attenuated by a detected object and not being attenuated by the detected object, further obtain the ratio of differential cross sections of the detected object to neutrons and the X rays, and determine the material type of the detected object through the corresponding relation between the ratio of differential cross sections of different materials to the neutrons and the X rays and the material, so that dual-energy detection of the neutrons and the X rays on the detected object is realized, nuclide types are obtained by utilizing different attenuation capacities of the material to the neutrons and the X rays, the element types are identified, and the detection accuracy is improved.

According to yet another aspect of some embodiments of the present disclosure, a computer-readable storage medium is proposed, on which computer program instructions are stored, which instructions, when executed by a processor, implement the steps of any of the dual mode detection methods mentioned above.

By executing the instructions on the computer-readable storage medium, detection data of X rays and neutron rays in the states of being attenuated by a detected object and not being attenuated by the detected object can be obtained, the specific value of the differential cross section of the detected object to neutrons and the X rays is further obtained, the substance type of the detected object is determined according to the corresponding relation between the specific value of the differential cross section of different substances to the neutrons and the X rays and the substance, therefore, dual-energy detection of the neutrons and the X rays to the detected object is achieved, nuclide types are obtained by the different attenuation capacities of the substances to the neutrons and the X rays, the element types are identified, and the detection accuracy is improved.

Further, according to an aspect of some embodiments of the present disclosure, there is provided a dual mode detection system, including: any of the above dual mode detection controllers; and, a dual mode detection apparatus, comprising: a single electron accelerator configured to emit electrons to the X-ray conversion target and the neutron conversion target simultaneously; the X-ray conversion target is configured to generate X-rays under excitation of electrons and emit from the first detection port; the neutron conversion target generates neutron rays configured to generate neutrons under excitation by electrons and emits from the second detection port.

Optionally, the dual mode detection device comprises at least one of the following structures: an X-ray chopper is arranged between the neutron conversion target and the second detection port; an X-ray collimator is arranged between the X-ray conversion target and the first detection port; or, a neutron collimator is included between the neutron conversion target and the second detection port.

Optionally, a line connecting the first detection port and the X-ray conversion target is perpendicular to a line connecting the second detection port and the neutron-ray conversion target.

The dual-mode detection system can detect and obtain X-rays and detection data of neutron rays in the states of being attenuated by a detected object and not being attenuated by the detected object, further obtain the ratio of the differential cross sections of the detected object to neutrons and the X-rays, and determine the material type of the detected object through the corresponding relation between the ratio of the differential cross sections of different materials to the neutrons and the X-rays and the material, thereby realizing dual-energy detection of the neutrons and the X-rays on the detected object, obtaining the nuclide type by utilizing different attenuation capacities of the material to the neutrons and the X-rays, realizing element type identification and improving the detection accuracy.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and not to limit the disclosure. In the drawings:

fig. 1 is a flow chart of some embodiments of a dual mode detection method of the present disclosure.

Fig. 2 is a schematic diagram of some embodiments of a dual mode detection apparatus employed by the dual mode detection method of the present disclosure.

Fig. 3A is a schematic perspective view of some embodiments of a dual mode detection apparatus used in the dual mode detection method of the present disclosure.

Fig. 3B is a schematic cross-sectional diagram of some embodiments of a dual mode detection device employed in the dual mode detection method of the present disclosure.

FIG. 4 is a flow chart of some embodiments of determining the ratio of differential cross-sections of an object under test for neutrons and X-rays in a dual mode detection method of the present disclosure.

FIG. 5 is a flow chart of further embodiments of a dual mode detection method of the present disclosure.

Fig. 6 is a schematic diagram of some embodiments of a dual mode detection controller of the present disclosure.

FIG. 7 is a schematic diagram of some embodiments of a ratio determination module in a dual mode detection controller according to the present disclosure.

FIG. 8 is a schematic diagram of further embodiments of a dual mode detection controller of the present disclosure.

FIG. 9 is a schematic diagram of yet other embodiments of a dual mode detection controller according to the present disclosure.

FIG. 10 is a schematic diagram of some embodiments of dual mode detection systems of the present disclosure.

Detailed Description

The technical solution of the present disclosure is further described in detail by the accompanying drawings and examples.

A flow diagram of some embodiments of a dual mode detection method of the present disclosure is shown in fig. 1.

In step 101, a ratio of differential cross sections of the object to be measured with respect to neutrons and X-rays is determined based on the X-ray object detection data, the X-ray no-object detection data, the neutron object detection data, and the neutron no-object detection data. In some embodiments, the object to be measured may be placed in the X-ray detection region and the neutron detection region respectively for detection while keeping the intensity of the radiation from the X-ray source and the neutron source unchanged, so as to obtain X-ray object detection data, X-ray no-object detection data, neutron object detection data, and neutron no-object detection data.

In step 102, the substance type is identified according to the corresponding relation between the ratio of the differential cross section of the measured object to the X-ray and the neutron and the substance type. In some embodiments, the material type of the object to be measured can be determined by performing a numerical comparison based on pre-stored ratios of differential cross sections of different materials with respect to X-rays and neutrons.

In some embodiments, the ratio of the differential cross section of the object to be detected to the X-ray and the neutron can be imaged, for example, different colors are used for displaying in different ratio value ranges, or a highlight effect is performed on the determined dangerous substance, so that the detection result is visualized, and the user friendliness is improved.

By the method, detection data of X-rays and neutron rays in the states of being attenuated by a detected object and not being attenuated by the detected object can be respectively obtained, the specific value of the differential cross section of the detected object to neutrons and the X-rays is further obtained, the substance type of the detected object is determined according to the corresponding relation between the specific value of the differential cross section of different substances to the neutrons and the X-rays and the substance, so that dual-energy detection of the neutrons and the X-rays to the detected object is realized, the nuclide type is obtained by utilizing different attenuation capacities of the substance to the neutrons and the X-rays, the element type is identified, and the detection accuracy is improved.

In some embodiments, the dual mode detection device as shown in fig. 2 may be employed to acquire detection data. The dual mode detection device 200 may include a first detection port 211, an X-ray detector 212, a second detection port 221, and a neutron detector 222, wherein an X-ray beam emitted from the first detection port 211 is received by the X-ray detector 212, and a neutron beam emitted from the second detection port 221 is received by the neutron detector 222. When the object to be detected is placed between the first detection port 211 and the X-ray detector 212, acquiring X-ray object detection data according to a detection result of the X-ray detector 212, and acquiring neutron no-object detection data according to a detection result of the neutron detector 222; when the object to be measured is placed between the second detection port 221 and the neutron detector 222, X-ray non-object detection data is obtained according to the detection result of the X-ray detector 212, and neutron object detection data is obtained according to the detection result of the neutron detector 222.

By the method, four items of data can be acquired by adopting the operations of one-time switching and two-time detection, and the time for acquiring the data is saved while the material identification is realized.

In some embodiments, to reduce the interference of X-rays with the neutron beam, a structure as shown in fig. 3A and 3B may be used. Fig. 3A is a schematic perspective view of some embodiments of a dual mode detection apparatus used in the dual mode detection method of the present disclosure. The electron linear accelerator 1 works in a pulse mode, electrons generate forward-rushing X-rays after bombarding the X-ray conversion target 2, and a part of the X-rays form an imaging X-ray beam 4 after being shielded by the X-ray collimator 6, penetrate through a measured object 11 and are measured by the X-ray imaging detector 5.

A neutron conversion target 3 is arranged beside the X-ray conversion target 2, and partial X-rays generated by the X-ray conversion target 2 react with the neutron conversion target 3 to generate a neutron beam 7 for neutron imaging. In some embodiments, the extraction direction of the neutron beam 7 is perpendicular to the electron direction striking the X-ray conversion target, and the arrangement is such that the X-ray has a forward momentum, but the 90-degree X-ray intensity is relatively weak, so as to reduce the interference of the X-ray pulse on the neutron beam.

In some embodiments, the high energy electron accelerator may be used to generate X-rays, which may then be neutralizedDaughter transformation targets (e.g. deuterium oxide D) ₂O) to generate a (γ, n) reaction, and neutrons are emitted from a predetermined direction after being moderated and decelerated and reflected by the reflector.

The neutron beam current 7 passes through the object to be measured 11 and is measured by the neutron imaging detector 8. In some embodiments, to improve the measurement environment, it is desirable that a neutron collimator 9 may be disposed between the neutron conversion target 3 and the neutron detector to collimate the neutron beam 7. Furthermore, in some embodiments, an X-ray chopper 10 may be further disposed between the neutron conversion target 3 and the second detection port to reduce the influence of the X-ray pulse on the neutron detector.

In some embodiments, the positional relationship of the X-ray conversion target 2 and the neutron conversion target 3 may be as shown in fig. 3B. The neutron conversion target 3 is positioned on the side surface of the X-ray conversion target 2, and the neutron conversion target and the X-ray conversion target are perpendicular to each other. The curve with arrows in fig. 3B is the X-ray marker and the straight line with a dot head is the neutron marker. It can be seen that after the rays pass through the X-ray chopper 10, the X-rays are removed, leaving a neutron beam to detect the object 11 to be measured.

The dual-mode detection device can simultaneously generate an X-ray beam and a neutron beam by adopting a single electron accelerator, thereby reducing the cost, reducing the volume of the equipment and being convenient for depending on the material type of an object to be lifted in the single equipment.

In one embodiment, the X-ray source can be implemented by electron bombardment of a pulsed linear electron accelerator onto an X-ray conversion target (W-Au composite target), and existing 2.5 MeV-15 MeV accelerators can be used (9MeV, 15MeV accelerators have been successfully used in industrial camera systems).

The neutrons of the source are prepared by X-ray through (gamma, n) reaction, and table 1 shows the photoneutron reaction threshold and cross section of some common nuclides, and it can be seen that the threshold is usually around 7MeV, which is equivalent to the average binding energy of the nuclei. Of these, 9Be and 2H have the lowest thresholds of 1.67MeV and 2.223MeV, respectively. The photoneutron reaction thresholds and cross-sections for different nuclear species can be shown in the following table:

TABLE 1 photoneutron response thresholds and Cross sections of different nuclides

In some embodiments, the relation between the photoneutron reaction cross section and the energy and protection conditions of the accelerator is comprehensively considered, an electron accelerator of 2.5-10 MeV can be adopted, and the accelerators have better performances in technical maturity and cost. Higher energy accelerators are not convenient due to problems that can lead to air activation.

A flow chart of some embodiments of determining the ratio of differential cross-sections of an object under test for neutrons and X-rays in a dual mode detection method of the present disclosure is shown in fig. 4.

In step 401, the mass attenuation of the neutron by the object under test is determined from the neutron object detection data and the neutron no-object detection data.

In step 402, the mass attenuation of the object under test for X-rays is determined from the X-ray object detection data and the X-ray no-object detection data.

In one embodiment, the following is expressed by the formula:

can obtain mu _D,mt _m＝ln(I _n,0/I _n,D) (1)

In the same way, mu _X,mt _m＝ln(I _X,0/I _X,D) (2)

Wherein, I _n,0、I _n,D、I _X,0And I _X,DNeutron no-object detection data, neutron object detection data, X-ray no-object detection data, and X-ray object detection data, mu _nAnd mu _n,mRespectively, neutron linearity, mass attenuation coefficient, mu _XAnd mu _X,mRespectively, X-ray linearity, mass attenuation coefficient, t and t _mRespectively the thickness and mass thickness of the object to be measured.Mu due to Compton scattering of MeV energy photons _n,m、μ _X,mThe energy region can be regarded as a constant approximately.

In step 403, the ratio of the differential cross-sections of the object to be measured for neutrons and X-rays is determined according to the mass attenuation of the object to be measured for neutrons and for X-rays. In one embodiment, the formulas (1) and (2) are combined to obtain

Namely:

coefficient of mass attenuation mu _mIs the differential cross section σ and the atomic mass m _AThe above formula can be further rewritten as:

if so:

then:

it can be seen that the measured value f (n) is determined by both the attenuation of the neutron rays and the attenuation of the X-rays, and that f (n) is determined, regardless of the mass thickness (or thickness) of the object to be measured, only by the differential cross section of the nuclei or atoms of the object to be measured to the neutrons or X-rays, or, so to speak, (given the neutron ray and X-ray energy constraints) f (n) is determined only by the nuclear/atomic properties of the substance, and therefore the type of the substance can be identified by f (n).

By the method, the ratio of the differential cross section of the measured object to the neutrons and the X rays can be obtained through a mathematical calculation mode based on the neutron non-object detection data, the neutron object detection data, the X-ray non-object detection data and the X-ray object detection data, the type of the substance can be conveniently identified through the ratio, and the determination efficiency of the type of the substance is improved.

A flow chart of further embodiments of the dual mode detection method of the present disclosure is shown in fig. 5.

In step 501, the ratio of differential cross-sections of the object under test to neutrons and X-rays is determined based on the X-ray object detection data, the X-ray no-object detection data, the neutron object detection data, and the neutron no-object detection data.

In step 502, the type of the substance is identified according to the correspondence between the ratio of the differential cross-section of the object to be measured for the X-rays and neutrons and the type of the substance.

In step 503, the relative contents of the various nuclides in the object under test are determined based on the ratio of the differential cross-sections of the object under test for neutrons and X-rays of different energies.

In some embodiments, f (n) obtained when using energy-divided neutron imaging may be considered, and has the following formula:

wherein F (n) _1,2…,m) Is F (n) obtained by utilizing ray sources with different energies, m is the energy zone number of neutron energy components, A _1……kThe elements in the right matrix reflect the corresponding f (n) values of different nuclides at different energy regions for the relative contents of the various major nuclides in the object under test. The number of m can be adjusted during the measurement, m can be made k, and then by the formula:

determining the relative content A of the number of various nuclides ₁～A _kWherein σ is _ni,jIs the differential cross-section of neutrons for the ith energy region of the jth nuclide, σ _X,jTo is in response toDifferential cross-section of the X-ray of the jth nuclide, F (n) _i) Is the ratio of the differential cross-section of the measured object for neutrons to X-rays in the i energy region, A _jI is more than or equal to 1 and less than or equal to m, j is more than or equal to 1 and less than or equal to k, m is the number of neutron energy regions, k is the number of nuclide species, and the number of energy regions is adjusted to make m equal to k in the measurement process.

By such a method, the content and composition of each element (nuclide) in the object to be detected can be further known, and the accuracy of detection can be further improved.

A schematic diagram of some embodiments of a dual mode detection controller of the present disclosure is shown in fig. 6. The ratio determination module 61 can determine the ratio of the differential cross section of the object to be measured with respect to neutrons and X-rays according to the X-ray object detection data, the X-ray no-object detection data, the neutron object detection data, and the neutron no-object detection data. In some embodiments, the object to be measured may be placed in the X-ray detection region and the neutron detection region respectively for detection while keeping the intensity of the radiation from the X-ray source and the neutron source unchanged, so as to obtain X-ray object detection data, X-ray no-object detection data, neutron object detection data, and neutron no-object detection data. The substance identification module 62 can identify the substance type according to the correspondence between the ratio of the differential cross section of the object to be measured with respect to the X-rays and the neutrons and the substance type. In some embodiments, the material type of the object to be measured can be determined by performing a numerical comparison based on pre-stored ratios of differential cross sections of different materials with respect to X-rays and neutrons.

The controller can respectively obtain detection data of X rays and neutron rays in the states of being attenuated by a detected object and not being attenuated by the detected object, further obtain the specific value of the differential cross section of the detected object to neutrons and the X rays, and determine the material type of the detected object through the corresponding relation between the specific value of the differential cross section of different materials to the neutrons and the X rays and the material, thereby realizing dual-energy detection of the neutrons and the X rays to the detected object, obtaining the nuclide type by utilizing different attenuation capacities of the material to the neutrons and the X rays, realizing element type identification and improving the detection accuracy.

In some embodiments, the dual-mode detection controller may further include an imaging module 63, which can perform imaging according to a ratio of the measured object to the differential cross section of the X-ray and the neutron, for example, different color display is adopted for different ratio value ranges, or a highlight display effect is performed on a determined hazardous substance, so that a detection result is visualized, and user friendliness is improved.

A schematic diagram of some embodiments of a ratio determination module in a dual mode detection controller of the present disclosure is shown in fig. 7. The detection data acquisition unit 711 can acquire the detection data of the X-ray object according to the detection result of the X-ray detector and acquire the detection data of the neutron-free object according to the detection result of the neutron detector when the object to be detected is located at the first detection port; when the object to be detected is located at the second detection port, neutron object detection data are obtained according to the detection result of the neutron detector, X-ray no-object detection data are obtained according to the detection result of the X-ray detector, wherein the first detection port emits X-rays, and the second detection port emits neutron rays. In some embodiments, the dual mode detection device may be as shown in fig. 2, 3A, 3B. The ratio operation unit 712 determines the ratio of the differential cross section of the object to be measured with respect to the X-ray and the neutron from the X-ray object detection data, the X-ray no-object detection data, the neutron object detection data, and the neutron no-object detection data.

The dual-mode detection controller can acquire four items of data by adopting the operations of one-time switching and two-time detection, and saves the time for acquiring the data while realizing the material identification.

In some embodiments, the ratio determining module may respectively calculate the mass attenuation of the measured object for neutrons and the mass attenuation of the measured object for X-rays in the manner as in the embodiment shown in fig. 4, so as to determine the ratio of the differential cross section of the measured object for neutrons and X-rays. The ratio determination module may also directly utilize equation (3) above to obtain the ratio determination module, which may be f (n).

The dual-mode detection controller can obtain the ratio of the differential section of the measured object to the neutrons and the X rays based on the neutron non-object detection data, the neutron object detection data, the X-ray non-object detection data and the X-ray object detection data in a mathematical calculation mode, so that the type of the substance can be conveniently identified through the ratio, and the determination efficiency of the type of the substance is improved.

In some embodiments, the ratio determining module may further determine the relative content of each nuclide in the object to be detected according to the ratio of the differential cross sections of the object to be detected with respect to neutrons and X-rays of different energies by using the above formula (4), so that the content and composition of each element in the object to be detected can be further known, and the detection accuracy can be further improved.

A schematic structural diagram of an embodiment of the dual mode detection controller of the present disclosure is shown in fig. 8. The dual mode probe controller includes a memory 801 and a processor 802. Wherein: the memory 801 may be a magnetic disk, flash memory, or any other non-volatile storage medium. The memory is for storing instructions in the corresponding embodiments of the dual mode detection method above. Coupled to the memory 801, the processor 802 may be implemented as one or more integrated circuits, such as a microprocessor or microcontroller. The processor 802 is configured to execute instructions stored in the memory, and can implement dual-energy detection of a measured object by using neutrons and X-rays, obtain a nuclide type by using different attenuation capabilities of a substance for neutrons and X-rays, identify an element type, and improve detection accuracy.

In one embodiment, as also shown in fig. 9, the dual mode detection controller 900 includes a memory 901 and a processor 902. The processor 902 is coupled to the memory 901 via a BUS 903. The dual mode detection controller 900 may also be coupled to an external storage 905 for invoking external data via storage interface 904, and may also be coupled to a network or another computer system (not shown) via network interface 906. And will not be described in detail herein.

In the embodiment, the data instruction is stored in the memory, and the instruction is processed by the processor, so that dual-energy detection of the neutron and the X-ray on the object to be detected can be realized, the nuclide type can be obtained by utilizing different attenuation capacities of the substance on the neutron and the X-ray, the element type can be identified, and the detection accuracy can be improved.

In another embodiment, a computer-readable storage medium has stored thereon computer program instructions which, when executed by a processor, implement the steps of the method in the corresponding embodiment of the dual mode detection method. As will be appreciated by one skilled in the art, embodiments of the present disclosure may be provided as a method, apparatus, or computer program product. Accordingly, the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present disclosure may take the form of a computer program product embodied on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

A schematic diagram of some embodiments of the dual mode detection system of the present disclosure is shown in fig. 10. The dual mode detection controller 1001 may be any of the dual mode detection controllers mentioned above. The dual mode detection device 1002 may include a single electron accelerator capable of emitting electrons synchronously to the X-ray conversion target and the neutron conversion target; the X-ray conversion target is configured to generate X-rays under excitation of electrons and emit from the first detection port; the neutron conversion target generates neutron rays configured to generate neutrons under excitation by electrons and emits from the second detection port.

The dual-mode detection system can detect and obtain X-rays and detection data of neutron rays in the states of being attenuated by a detected object and not being attenuated by the detected object, further obtain the ratio of the differential cross sections of the detected object to neutrons and the X-rays, and determine the material type of the detected object through the corresponding relation between the ratio of the differential cross sections of different materials to the neutrons and the X-rays and the material, thereby realizing dual-energy detection of the neutrons and the X-rays on the detected object, obtaining the nuclide type by utilizing different attenuation capacities of the material to the neutrons and the X-rays, realizing element type identification and improving the detection accuracy.

In some embodiments, the dual mode detection apparatus may include an X-ray chopper 10 between the neutron conversion target 3 and the second detection port as shown in fig. 3A, 3B, which can reduce the influence of the X-ray pulse on the neutron detector.

In some embodiments, an X-ray collimator may be included between the X-ray conversion target 2 and the first detection port, and a neutron collimator may be included between the neutron conversion target and the second detection port, so as to achieve the effect of collimating X-ray and neutron beams.

In some embodiments, considering that the X-ray has a forward-impact property and the intensity of the X-ray in the 90-degree direction is relatively weak, a connecting line of the first detection port and the X-ray conversion target is perpendicular to a connecting line of the second detection port and the neutron-ray conversion target, so that the interference of the X-ray pulse on the neutron beam line is weakened.

The present disclosure is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the disclosure. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Thus far, the present disclosure has been described in detail. Some details that are well known in the art have not been described in order to avoid obscuring the concepts of the present disclosure. It will be fully apparent to those skilled in the art from the foregoing description how to practice the presently disclosed embodiments.

The methods and apparatus of the present disclosure may be implemented in a number of ways. For example, the methods and apparatus of the present disclosure may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order for the steps of the method is for illustration only, and the steps of the method of the present disclosure are not limited to the order specifically described above unless specifically stated otherwise. Further, in some embodiments, the present disclosure may also be embodied as programs recorded in a recording medium, the programs including machine-readable instructions for implementing the methods according to the present disclosure. Thus, the present disclosure also covers a recording medium storing a program for executing the method according to the present disclosure.

Finally, it should be noted that: the above examples are intended only to illustrate the technical solutions of the present disclosure and not to limit them; although the present disclosure has been described in detail with reference to preferred embodiments, those of ordinary skill in the art will understand that: modifications to the specific embodiments of the disclosure or equivalent substitutions for parts of the technical features may still be made; all such modifications are intended to be included within the scope of the claims of this disclosure without departing from the spirit thereof.