JP2009180563A - Explosive inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an explosive inspection device capable of smoothly performing inspection by effectively shielding γ rays. <P>SOLUTION: The explosive inspection device includes a neutron producing tube 11 for irradiating luggage 3 with neutrons; a γ-ray detector 13 for detecting γ rays produced by the irradiating neutron and an explosive determining part for determining the presence of an explosive from the detection result of the γ-ray detector 13. The γ rays emitted from the luggage 3 are cut off by an on-off lid 9 positioned at an open position, when the luggage is installed and forming a hermetically closed space at a closed position at inspection and the peripheral wall part 7. A table on which the luggage 3 is placed and which moves the luggage to the inspection position from an installation position is provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an explosives inspection apparatus that irradiates neutrons and inspects for the presence or absence of explosives with generated γ rays.

  Explosives inspection equipment that inspects the presence of explosives in the specimen by irradiating the specimen such as baggage with fast neutrons and thermal neutrons emitted from pulsed neutrons and detecting the inherent γ rays generated Is known (see Patent Document 1).

JP 2007-187467 A (paragraph [0027] and FIG. 3)

  In this case, it is necessary to effectively shield the γ-rays generated at the time of inspection and perform the inspection smoothly, but there is no specific proposal for this.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the explosives inspection apparatus which can shield a gamma ray effectively and can test | inspect smoothly.

In order to solve the above problems, the explosives inspection apparatus of the present invention employs the following means.
That is, the explosives inspection apparatus according to the present invention includes a neutron generation source that irradiates an inspection object with neutrons, a γ-ray detector that detects γ-rays generated by the irradiated neutrons, and the γ-ray detector. An explosives inspection apparatus comprising an explosives determination unit for determining the presence or absence of explosives from a detection result, wherein the explosives inspection unit is located at an open position when installing the inspection object and a closed space at a closed position at the time of inspection. A container that includes an openable / closable lid to be formed, shields γ rays generated from the inspection object, and a table on which the inspection object is placed and moves the inspection object from the installation position to the inspection position. It is characterized by.

  Γ-rays generated by neutrons irradiated on the inspection object are shielded in a container closed by an opening / closing lid. On the other hand, the inspection object is moved from the installation position to the inspection position by the table. Thereby, an explosive can be inspected safely and smoothly.

  Furthermore, in the explosives inspection apparatus of the present invention, the table is rotatable around a rotation axis intersecting with an axis connecting the neutron generation source and the γ-ray detector at the time of inspection. And

  Because the table can rotate the specimen around the axis of rotation that intersects the axis connecting the neutron source and the γ-ray detector, the explosives present in the specimen are biased Even so, an averaged output can be obtained, and explosives can be detected with high accuracy.

  Furthermore, in the explosives inspection apparatus of the present invention, the table is capable of reciprocating in a tolerance direction intersecting with an axis connecting the neutron generation source and the γ-ray detector at the time of inspection. And

  The table can reciprocate the inspection object in the direction of tolerance that intersects the axis connecting the neutron source and the γ-ray detector, so that the explosives present in the inspection object are biased. Even so, an averaged output can be obtained, and explosives can be detected with high accuracy.

  Furthermore, the explosives inspection apparatus according to the present invention is characterized in that a vacuum evacuation means is provided for evacuating the closed space in the container during the inspection.

  Nitrogen and oxygen in the air present in the container cause background generation for the γ-ray detector. In the present invention, since the sealed space in the container is evacuated during the inspection, the inspection accuracy can be improved by suppressing the generation of the background as much as possible.

  Furthermore, the explosives inspection apparatus of the present invention is characterized by comprising gas replacement means for replacing the gas in the sealed space in the container with a rare gas during the inspection.

Nitrogen and oxygen in the air present in the container cause background generation for the γ-ray detector. In the present invention, since it is replaced with a rare gas that does not cause background generation, the inspection accuracy can be improved.
Note that argon is suitable as the rare gas in consideration of availability and cost.

  Further, the explosives inspection apparatus of the present invention includes a storage container that stores the inspection object and has a scale formed thereon, and a control unit that controls the operation of the table based on an output of an imaging unit that reads the scale. It is characterized by.

  Since the table can be operated by referring to the scale formed on the storage container, the inspection position can be set accurately and the inspection accuracy can be improved.

  Furthermore, in the explosives inspection apparatus of the present invention, the storage container is made of a material that can be seen through by the photographing means.

Since the storage container is made of a material that can be seen through by the imaging means, the inspection object located in the storage container can also be imaged, and the position and dimensions of the inspection object can be accurately acquired. Thereby, the inspection accuracy is further improved.
In addition, as a material of a storage container, organic materials, such as polyethylene, a polyester, and a polypropylene, are preferable. These have the advantage that they are not activated even after repeated use, compared to metal materials such as iron and aluminum.

  According to the present invention, the γ rays are shielded in the container closed by the opening / closing lid, and the inspection object is moved from the installation position to the inspection position by the table, so that the explosive can be inspected safely and smoothly.

Embodiments according to the present invention will be described below with reference to the drawings.
[First embodiment]
FIG. 1 shows an explosives inspection apparatus 1 according to this embodiment.
The explosive inspection apparatus 1 includes a table 5 on which a baggage (inspection object) 3 is placed, a peripheral wall portion 7 provided so as to form an inspection space S therein, and an open / close lid 9 that closes the upper end of the peripheral wall portion 7. It has.
The peripheral wall portion 7 is disposed so as to surround the table 5 by being positioned inside. The peripheral wall part 7 is comprised with the material which absorbs and shields a gamma ray, for example, lead is used suitably. The peripheral wall 7 is provided in a hole excavated downward from the ground G.
A neutron generating tube 11 and a γ-ray detector 13 are installed on the peripheral wall 7. The neutron generating tube 11 and the γ-ray detector 13 are arranged at positions facing each other with the examination space S interposed therebetween.
As shown in FIG. 3, the neutron generating tube 11 generates pulse neutrons n from a neutron generating source 11a at a substantially central position.
The γ-ray detector 13 detects γ-rays emitted from explosives in the baggage 3 by pulsed neutrons generated from the neutron generating tube 11. As the γ-ray detector 13, NaI, Ge, BGO or the like is used.

An opening / closing lid 9 is provided on the upper portion of the peripheral wall 7, and the inspection space S is opened and closed by the opening / closing lid 9. The open / close lid 9 is slidable along the ground G, and reciprocates between the sealed position shown in FIG. 1 and the open position shown in FIG. The opening / closing lid 9 is also made of a material that absorbs and shields γ rays, like the peripheral wall portion 7, and for example, lead is preferably used.
The peripheral wall portion 7 and the opening / closing lid 9 constitute a container that shields γ rays generated from the baggage 3.

The table 5 includes a base part 5a on which the baggage 4 is placed and a shaft part 5b that supports the base part 5a from below.
The table 5 is rotatable about a rotation axis substantially orthogonal to an axis connecting the neutron generator tube 11 and the γ-ray detector 11. Specifically, as shown in FIG. 3, the shaft portion 5b having the same axis as the rotation axis rotates in the direction of arrow R.
The table 5 can be moved up and down in the direction of arrow V. Thus, the table 5 can reciprocate between the inspection position in the inspection space S shown in FIG. 1 and the installation position shown in FIG. Here, the installation position means a position where the baggage is installed on the platform 5a of the table 5 outside the inspection space S.

Although not shown, the explosives inspection apparatus 1 includes an explosive determination unit that determines the presence or absence of explosives from the detection result of the γ-ray detector 13. A known method can be used to determine the presence or absence of explosives. For example, if a chemical substance is identified from the energy corresponding to the peak position of the obtained output and this chemical substance corresponds to an explosive, an explosion may occur. It is determined that an object exists.
Furthermore, the explosives inspection apparatus 1 includes a camera (imaging means) that captures the baggage 3.

The baggage 3 is stored in the storage container 15. The storage container 15 is made of an organic material such as polyethylene, polyester, or polypropylene. These materials have an advantage that they are not activated even after repeated use, compared to metal materials such as iron and aluminum. In this way, if a material such as polyethylene is used, the storage container 15 can be made translucent, so that the baggage 3 located in the storage container 15 can be simultaneously photographed with the camera.
As shown in FIG. 4, a scale L is formed in the storage container 15. Thereby, the position and dimension of the baggage 3 in the storage container 14 can be specifically specified with a camera.

Next, the usage method of the explosives inspection apparatus 1 of the said structure is demonstrated.
First, the baggage 3 is stored in the storage container 15, and the baggage 3 is placed on the table 5 together with the storage container 5 as shown in FIG. 2. As shown in FIG. 2, since the table 5 is raised to the installation position, the baggage 3 can be easily installed outside the storage space S. At this installation position, the position and dimensions of the baggage 3 relative to the storage container 15 are grasped by the camera. Specifically, referring to the scale L shown in FIG. 4, the dimensions of the baggage 3, the center position C, the lower end position P1, the upper end position P2 (see FIG. 5), and the like are acquired.
Thereafter, the table 5 descends, and the baggage 3 is positioned in the inspection space S as shown in FIG. The stop position in the vertical direction of the table 5 is such that the center position C of the baggage acquired by the camera is at the same height as the neutron generation source 11a of the neutron generation tube 11 (see FIG. 5). Thereby, it is possible to irradiate the entire baggage 3 with pulsed neutrons from the center.

Then, pulse neutrons are generated from the neutron generator tube 11, the baggage 3 is irradiated with the pulsed neutrons, and γ-rays generated from the baggage 3 are detected by the γ-ray detector 13. At the time of this inspection, as shown in FIG. 3, the inspection is performed while rotating the table. As a result, even when explosives are present in the baggage 3 in a biased manner, an output integrated in the rotational direction can be obtained, so that detection can be performed without oversight.
The output from the γ-ray detector 13 is obtained, and the explosives determination unit detects whether or not there is a chemical substance peak corresponding to the explosive and determines the presence or absence of the explosive.

  At the time of inspection, not only the table 5 but also the table 5 may be moved up and down. Specifically, from the state where the neutron generation source 11a and the lower end position P1 of the baggage 3 are at the same height position (see FIG. 6), the neutron generation source 11a and the upper end position P2 of the baggage 3 are at the same height position. The table is moved up and down until it reaches a state (see FIG. 7). Thereby, pulse neutrons can be irradiated evenly in the vertical direction of the baggage 3.

As described above, according to the present embodiment, the following operational effects are obtained.
Γ rays generated by the pulsed neutrons irradiated to the baggage 3 are shielded in the inspection space S closed by the opening / closing lid 9. On the other hand, the baggage 3 is moved by the table 5 from the installation position (see FIG. 2) to the inspection position (see FIG. 1). Therefore, explosives can be inspected safely and smoothly.
In addition, since the table 3 is used to rotate the baggage 3 during the inspection, the baggage can be uniformly irradiated with neutrons, and the explosives present in the baggage are unevenly present. Even if it exists, the output integrated in the rotation direction of the baggage 3 can be obtained, and the explosive can be detected with high accuracy.
Further, since the table 5 can be operated by referring to the scale L formed on the storage container 15, the inspection position can be set accurately and the inspection accuracy can be improved.
In addition, since the storage container 15 is made of a material that can be seen through with a camera, it is possible to photograph the baggage located in the storage container 15 and accurately grasp the position of the baggage. Can be further improved.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment is different from the first embodiment in that a vacuum evacuation unit is provided, and the other parts are the same. Therefore, the same components are denoted by the same reference numerals, and the description thereof is omitted.
A vacuum pump 20 for evacuating the inspection space S is provided. The vacuum pump 20 and the inspection space S are connected by an exhaust pipe 22, and an open / close valve 24 is provided in the exhaust pipe 22.
In order to keep the inside of the inspection space S airtight, a seal member 26 is provided between the opening / closing lid 9 and the peripheral wall portion 7. Similarly, the lower wall portion 27 is fixed to the lower end of the peripheral wall portion 7 in order to seal the lower end of the peripheral wall portion 7. A hole through which the shaft portion 5b of the table 5 is inserted is formed in the lower wall portion 27, and a seal member 28 is provided so as to seal the hole.
With the above configuration, the inspection space S can be evacuated during inspection. As a result, nitrogen and oxygen, which cause background generation for the γ-ray detector 13, can be eliminated, so that the inspection accuracy can be improved.

[Third embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. This embodiment is different from the first embodiment in that a gas replacement unit is provided, and the other parts are the same. Therefore, the same components are denoted by the same reference numerals, and the description thereof is omitted. Moreover, the same code | symbol is attached | subjected about the structure which is common in 2nd embodiment, and the description is abbreviate | omitted.
In the inspection space S, a supply pipe 32 for supplying argon gas (rare gas) and an exhaust pipe 36 for exhausting the gas in the inspection space S are provided. An argon gas cylinder 30 is connected to the supply pipe 32 via an open / close valve 34.
With the above configuration, the argon gas can be supplied into the inspection space S, the gas in the inspection space S can be exhausted through the exhaust pipe 36, and the gas in the inspection space S can be replaced with argon gas. Since argon gas does not cause a background for the γ-ray detector 13, the inspection accuracy can be improved.

It is an explosives inspection apparatus concerning a first embodiment of the present invention, and is a schematic sectional side view showing a position at the time of inspection. FIG. 2 is a schematic sectional side view showing an installation position for installing baggage, which is the explosives inspection apparatus of FIG. 1. It is the perspective view which showed a mode that the table rotated and moved up and down with respect to the neutron generator tube. It is the front view which showed the baggage installed in the storage container which can be seen through with a camera. It is the side view which showed the state which made the height center of baggage correspond with the neutron generation source. It is the side view which showed the state which matched the lower end position of the baggage with respect to the neutron generation source. It is the side view which showed the state which matched the upper end position of the baggage with respect to the neutron generation source. It is the schematic sectional side view which showed the explosives test | inspection apparatus concerning 2nd embodiment of this invention. It is the schematic sectional side view which showed the explosives test | inspection apparatus concerning 3rd embodiment of this invention.

Explanation of symbols

1 Explosives Inspection Device 3 Baggage (Inspection)
5 Table 7 Perimeter wall (container)
9 Open / close lid (container)
11 Neutron generator tube (neutron source)
13 γ-ray detector 15 Storage container 20 Vacuum pump (evacuation means)
22 Exhaust pipe (vacuum exhaust means)
30 Argon gas cylinder (gas replacement means)
32 Supply pipe (gas replacement means)
36 Exhaust pipe (gas replacement means)
S inspection space

Claims (7)

A neutron source that irradiates the inspection object with neutrons, a γ-ray detector that detects γ-rays generated by the irradiated neutrons, and an explosive that determines the presence or absence of explosives from the detection results of the γ-ray detector An explosives inspection device comprising a determination unit,
A container that shields γ-rays generated from the inspection object, comprising an open / close lid that forms an open space at the closed position at the time of inspection when the inspection object is installed, and
A table for placing the inspection object and moving the inspection object from the installation position to the inspection position;
An explosives inspection device characterized by comprising:   2. The explosives inspection according to claim 1, wherein the table is rotatable around a rotation axis intersecting with an axis connecting the neutron generation source and the γ-ray detector at the time of inspection. apparatus.   3. The explosion according to claim 1, wherein the table is capable of reciprocating in a tolerance direction intersecting with an axis connecting the neutron generation source and the γ-ray detector at the time of inspection. Inspection equipment.   The explosives inspection apparatus according to any one of claims 1 to 3, further comprising an evacuation unit that evacuates the closed space in the container during the inspection.   The explosives inspection apparatus according to any one of claims 1 to 3, further comprising gas replacement means for replacing a gas in the sealed space in the container with a rare gas during the inspection. A storage container for storing the inspection object and having a scale formed thereon;
Control means for controlling the operation of the table based on the output of the photographing means for reading the scale;
The explosives inspection apparatus according to any one of claims 1 to 5, further comprising:   The explosives inspection apparatus according to claim 6, wherein the storage container is made of a material that can be seen through by the photographing unit.

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