JP3827224B2 - Luggage inspection device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a passenger baggage inspection apparatus at an airport or the like, for example, and relates to a baggage inspection apparatus suitable for nondestructively detecting explosives, prohibited drugs, and the like in baggage.
[0002]
[Prior art]
There is a growing need for fast and reliable detection of explosives and forbidden drugs in baggage at airports (eg, Non-Patent Document 1). US Federal Aviation Administration (FAA) guidelines, for example, carry-on baggage , It is said that 0.5 pound (227 g) TNT explosives can be detected in 6 seconds, and specifications with a detection rate of 95% or more and a false alarm rate of 2% or less are desired for explosives detection devices.
[0003]
A typical inspection method is X-ray CT. In X-ray CT, the shape and multidimensional density space distribution information of an inspection object are obtained. Therefore, an object close to the density of explosives can be determined as a dangerous substance. However, since information beyond the density cannot be obtained for the inspection object, it is difficult to reliably identify explosives, and the detection rate or false alarm rate is not sufficient. A method using a nuclear reaction by neutron irradiation has also been proposed. Due to neutron irradiation, different elements such as carbon, nitrogen, and oxygen emit gamma rays having their own energy spectrum. Therefore, by obtaining the spatial distribution of the γ-ray energy spectrum, it is possible in principle to obtain the spatial distribution information of the elemental composition and directly detect explosives.
[0004]
In addition to the method using X-ray CT and the method using neutron irradiation, various inspection methods such as X-ray diffraction, X-ray fluoroscopy with multiple energies, nuclear magnetic resonance and nuclear quadrupole resonance have been proposed. However, none of the inspection methods are reliable alone.
[0005]
By the way, an explosive detection technique combining X-ray CT and neutron inquiry is known (see, for example, Patent Document 1). In this technique, a system having a neutron and gamma ray detector array is used as a neutron inquiry system. The neutron inquiry system includes a plurality of neutron sources and an arrayed two-dimensional γ-ray detector, and sandwiches an inspection object.
[0006]
[Non-Patent Document 1]
“Radio Isotope”, Volume 42, published in 1993 (pages 413 to 422)
[Patent Document 1]
JP 10-510621 Gazette (page 17, Fig. 5 etc.)
[0007]
[Problems to be solved by the invention]
However, the prior art described in Patent Document 1 requires a planar area for both the neutron and γ-ray detector arrays. As for neutrons, a one-dimensional array is mechanically scanned in a direction perpendicular to the array. Here, it is possible to mechanically scan one neutron source in two directions, or to provide a two-dimensional array of neutron sources in advance and omit mechanical scanning. However, the two-dimensional planar area is still necessary for the neutron source. The same applies to the γ-ray detector array, which is a two-dimensional array having the same size as the inspection object. For this reason, the entire inspection apparatus becomes large, and in particular, it is impossible to install the X-ray CT and the neutron inquiry system in combination at the same position in the moving direction of the inspection object, which increases the inspection apparatus size. There is a problem.
[0008]
In the prior art described in Patent Document 1, the concentrations of at least two elements are displayed as information from the neutron inquiry system and X-ray CT. However, the element concentration display has a problem that the detection rate of explosives is not improved.
[0009]
Therefore, the main object of the present invention is to provide a luggage inspection apparatus that can reduce the installation space and improve the detection rate of explosives.
[0010]
[Means for Solving the Problems]
The baggage inspection apparatus of the present invention that has solved the above problems is an inspection apparatus for nondestructively inspecting the contents of a baggage. CT This X-ray imaging apparatus X-ray generator and X-ray detector And neutrons CT neutron generator and γ-ray detector In the direction of baggage transport Vertical On the same cross section The neutron CT identifies the flight direction of neutrons by detecting α particles flying in the opposite direction to the neutrons generated by the neutron generator with an α-ray detector. A neutron CT signal processing device that identifies the flight time of neutrons and the elements that have reacted with neutrons by detecting γ-rays generated by the reaction with a γ-ray detector, and further identifies the positions of the elements in the three-dimensional direction. Yes It was set as the structure to do. The same cross section does not mean literally the same, but includes the vicinity.
[0011]
Moreover, the luggage inspection apparatus of the present invention that has solved the above problems is an inspection apparatus for nondestructively inspecting the contents of a luggage, The γ-ray detector has X-ray shielding. It was set as the structure to do.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a package inspection apparatus according to an embodiment of the present invention will be described in detail. The baggage inspection apparatus according to an embodiment is an explosives detection apparatus for nondestructively inspecting the presence or absence of explosives in baggage at an airport or the like, and includes an X-ray imaging apparatus and neutron CT (Computed Tomography). .
[0013]
≪Composition of explosives detection device≫
An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing an example of an explosive detection device used for baggage inspection. FIG. 2 is a cross-sectional view showing an arrangement structure example of an X-ray generator, an X-ray detector array, a neutron generator, a γ-ray detector, etc. in the explosive detection device. FIG. 3 is a diagram illustrating a configuration example of a main part of the neutron CT. FIG. 4 is a diagram illustrating a display example of the display device.
[0014]
As shown in FIG. 1, an explosive detection device A according to an embodiment includes a conveying means 3 such as a belt conveyor, a device wall 4 covering the explosive detection device A and shielding radiation, an X-ray generator 5, and an X-ray generator 5. Ray detector arrays 6, 7, neutron generator 8, alpha ray detector array 9, gamma ray detector 10, X-ray detection signal processor 11, neutron CT signal processor 12, image processor 13a, display device 13b, The baggage detection sensor 21 and other control devices (not shown) that collectively control the explosives detection device A are configured.
[0015]
As shown in FIG. 2, the explosives detection apparatus A of one embodiment arrange | positions the X-ray generator 5 and the X-ray detector arrays 6 and 7 in the same cross section of the apparatus wall 4 which also shields radiation, In the same cross section, the neutron generator 8 and the γ-ray detector 10 are arranged to shorten the size (length) of the explosives detector A in the depth direction. That is, each device such as the X-ray generator 5 is disposed at a position on the same cross section where each of them does not interfere. Note that a plurality of γ-ray detectors 10 may be arranged as indicated by virtual lines.
[0016]
(X-ray imaging device)
The explosive detection device A according to an embodiment includes an X-ray imaging device and a neutron CT. First, the X-ray generator 5, the X-ray detector arrays 6 and 7, the X-ray detection signal processing device 11, and the image processing device. An X-ray imaging apparatus including 13a and other control devices not shown will be described with reference to FIGS.
[0017]
The X-ray generator 5 shown in FIGS. 1 and 2 has an X-ray tube (not shown). This X-ray tube has a filament hot cathode made of tungsten, for example, and electrons emitted from the filament are accelerated by applying a voltage (several hundred kV) and collide with a target (Mo, W, etc.) that is an anode. X-rays are generated. X-rays are emitted from the X-ray generator 5 by opening an X-ray emission switch (not shown). The emitted X-ray has a fan shape with a certain thickness (for example, 80 ° in the circumferential direction and 5 ° in the direction orthogonal to the circumferential direction). The X-ray emission (irradiation) direction is the direction of X-ray detector arrays 6 and 7 to be described next, and the X-ray generator 5 explodes so that X-rays can be emitted in such a direction. It is attached in the object detection apparatus A.
[0018]
The X-ray detector array 6 shown in FIGS. 1 and 2 is erected on the side of the conveying means 3, and each X-ray detector 6 a, 6 b, 6 c... Faces the detection surface toward the X-ray generator 5. Are arranged vertically. Further, the X-ray detector array 7 is provided on the lower surface of the transport unit 3 so as to be orthogonal to the transport direction of the transport unit 3. The X-ray detector array 7 has a configuration in which X-ray detectors 7 a, 7 b, 7 c... Are arranged in the horizontal direction with the detection surface facing the X-ray generator 5. The X-ray detectors 6a,..., 7a,... Are made of cadmium tellurium (CdTe), for example, a cubic semiconductor element portion of several mm. The X-ray detector arrays 6 and 7 and the X-ray generator 5 are arranged on the same plane in the explosive detection device A (see FIG. 2). Incidentally, the X-ray detector arrays 6 and 7 of this embodiment are one-dimensional arrays, and a two-dimensional transmission image is obtained by the movement of the baggage 1 itself.
[0019]
The X-ray detection signal processing device 11 is connected to the X-ray detectors 6a, 6b, 6c... Constituting the X-ray detector array 6 and the X-ray detectors 7a, 7b. Has been. In the X-ray detection signal processing device 11, the X-ray detection signals detected by the X-ray detectors 6a,.
[0020]
That is, the X-ray detection signal processing device 11 converts the X-ray absorption rate obtained from the X-ray detection signal into the density of the image. Absorption of X-rays by baggage 1 is expressed by the following equation.
[0021]
I = I ₀ exp (-μx)
I: X-ray intensity with baggage 1
I ₀ : X-ray intensity without baggage 1
μ: X-ray absorption coefficient
x: X-ray transmission length in baggage 1
[0022]
Therefore, the logarithm log (I ₀ By converting / I) = μx into, for example, color shading, a two-dimensional spatial distribution of X-ray transmittance can be imaged. In imaging, it is possible to perform data correction due to variations in sensitivity among the X-ray detector arrays 6 and 7 and differences in distance and field of view from the X-ray generator.
[0023]
(Neutron imaging device [neutron CT])
Next, the neutron CT included in the explosives detection apparatus A according to an embodiment will be described. In one embodiment, an inspection device (neutron imaging device) using neutrons combined with an X-ray imaging device is a neutron CT. The neutron CT is a radioisotope issued in the above-mentioned Non-Patent Document 1, that is, 1993. Volume 42, pages 413 to 422 (especially page 419, FIG. 15).
[0024]
First, the principle of neutron CT will be described. The neutron CT in this embodiment uses the following nuclear fusion reaction (DT reaction) as a neutron source.
D + T → α + n
[0025]
Here, D is a deuterium nucleus, T is a tritium nucleus, α is a helium nucleus, and n is a neutron (fast neutron). Alpha particles and neutrons are emitted in opposite directions, approximately 180 degrees, with constant energy of 3.5 MeV and 14 MeV, respectively. In this reaction, neutrons (and alpha particles) are emitted isotropically, and it is impossible to identify the direction of emission before the reaction occurs, or the alpha particle generation position (detection) in the vicinity of the fusion reaction generation region By detecting (monitoring) the position) and the generation time (detection time), it is possible to identify the generation time and flight direction of neutrons emitted in the opposite direction simultaneously with the α particles.
[0026]
Generated neutrons react with elements such as carbon C, nitrogen N, oxygen O, etc. constituting the object to be inspected (for example, explosives), and energy spectrum specific to the element involved in the reaction due to inelastic scattering (n, n ′) γ. Emits gamma rays with. By detecting (monitoring) this γ-ray, the element can be identified. Also, from the difference between the neutron generation time (α particle detection time and α particle flight distance) and γ ray detection time, the flight time of neutrons can be identified, along with the flight direction of neutrons previously determined by α particle detection, Three-dimensional position information and element information can be identified. In this way neutrons Irradiation 3D image by neutron CT image Configure.
[0027]
Next, FIG. 1 shows the configuration of neutron CT including the neutron generator 8, the γ-ray detector 10, the neutron CT signal processor 12, the image processor 13a, the display device 13b, and other control devices (not shown). Description will be given with reference to FIG.
[0028]
As shown in FIG. 3, the neutron generator 8 includes an ion source 14, a target 15, and an α-ray (α particle) detector array 9. The ion source 14 includes deuterium ions (D ⁺ ) Is accelerated to irradiate the target 15 containing tritium T. The target 15 is made of a hydrogen storage alloy or the like that stores tritium (T), and is a target of accelerated deuterium ions. The target 15 collides with the irradiated deuterium ions and the tritium occluded by the target 15, and at the time of the collision, a fusion reaction (DT reaction) between the deuterium ions and the tritium occurs and α particles (α Rays) and neutrons (neutron rays) are generated. In addition, the flight direction (traveling direction) of the generated α particles and neutrons is isotropic.
[0029]
As shown in FIG. 3, the α-ray detector array 9 is provided at a position facing the conveying means 3, that is, the explosive 2 (see baggage 1, FIG. 1) with the target 15 interposed therebetween. The α-ray detector array 9 has a configuration in which the α-ray detectors 9a, 9b,... Are arranged in a direction perpendicular to the transport direction of the transport means 3, as in the X-ray detector array 6 and the like. . The reason why they are arranged side by side is that the flight direction of α particles generated by the DT reaction is isotropic. Incidentally, the passing of the α-ray detector array 9 has such a size that the flight direction can be identified no matter which position in the width direction of the transport means 3 is irradiated with neutrons. That is, if the width of the conveying means 3 is wide, the passing length of the α-ray detector array 9 becomes long. The distance between the target 15 and the α-ray detector array 9 (each α-ray detector 9a, 9b...) Is measured in advance and stored in the neutron CT signal processing device 12.
This α-ray detector array 9 is connected to a neutron signal processing device 12, and the neutron signal processing device 12 is based on the information obtained from the α-ray detector array 9 and the flight direction of neutrons generated simultaneously with the α particles. And the flight time is identified.
[0030]
As the γ-ray detector 10 shown in FIG. 3, several types of semiconductor detectors and scintillators can be used. In this embodiment, a combination of an inexpensive NaI scintillator 16 and a photomultiplier tube 17 is used. Is used. The NaI scintillator 16 here is a crystal having a diameter of 20 cm and a thickness of 10 cm. Since γ-rays generated by the reaction between the elements constituting baggage 1 (explosive 2) and neutrons are emitted isotropically, a plurality of γ-ray detectors 10 are arranged to add signals. The sensitivity of explosive detection can also be improved (see the phantom line portion in FIG. 2).
[0031]
Incidentally, as shown in FIG. 2, the γ-ray detector 10 is covered with an X-ray shield 22 for the following reason. That is, the explosives detection apparatus A of one embodiment is provided with the X-ray generator 5 on the same cross section as the neutron CT apparatus (γ-ray detector 10). For this reason, the γ-ray detector 10 may detect X-rays. Therefore, as shown in FIG. 2, an X-ray shield 22 made of lead or the like is installed to shield X-rays, thereby improving the quality of γ-ray detection by the γ-ray detector 10. By the way, since the X-ray energy of the X-ray generator 5 is several hundred Kev or less, the X-ray detector arrays 6 and 7 intended to detect the X-rays of such energy have high energy of several MeV or more. It does not detect γ rays (γ rays generated by the reaction of neutrons with elements). For this reason, the X-ray detector arrays 6 and 7 need not be shielded. Note that the γ-ray detector 10 is connected to a neutron signal processing device 12, and the neutron CT signal processing device 12 identifies an element that has reacted with neutrons from the detected energy spectrum of γ-rays. Further, the neutron CT signal processing device 12 takes into account the information of the α-ray detector 9 and identifies the position in space of the element that has reacted with the neutron.
[0032]
The neutron CT signal processing apparatus 12 shown in FIG. 1 is connected to each α-ray detector 9a, 9b... And γ-ray detector 10 constituting the α-ray detector array 9 (see FIG. 3 and the like). The neutron CT signal processing device 12 monitors which α-ray detectors 9a, 9b... Detect α particles, and identifies the flight direction of the corresponding neutrons. Further, the flight time of neutrons is identified from the time when the α particles are detected and the detection time of the γ rays generated when the neutrons corresponding to the α particles react with the element. Note that the speed of γ rays, which are electromagnetic waves, is much faster than the flight speed of α particles and neutrons, and the flight speed of α particles and the flight speed of neutrons are almost constant. Can be identified (neutron time-of-flight method).
[0033]
Moreover, the neutron CT signal processing apparatus 12 identifies the element which reacted with the neutron and generate | occur | produced the gamma ray from the energy spectrum of the gamma ray.
[0034]
Then, the neutron CT signal processing device 12 combines these pieces of information to identify position information and element information of an element that has reacted with neutrons to emit γ rays. Further, by detecting a plurality of γ-rays, the carbon / oxygen ratio, nitrogen / oxygen ratio, etc. of the contents of baggage 1 (explosive 2) are calculated. That is, the composition ratio information of three or more elements is calculated.
[0035]
Note that the energy spectrum of γ-rays is specific to each substance, and by comparing the energy spectra of various explosives and non-explosives stored in advance in a database with the energy spectra of γ-rays at each position in a three-dimensional space, 3 The presence or absence of explosives at each position in the dimensional space can be determined (in this embodiment, the neutron CT signal processing device 12 includes such a database).
[0036]
Information obtained by these processes (neutron imaging signals and the like) is displayed as an image on the image processing device 13a and the display device 13b (see FIG. 4).
[0037]
The neutron CT according to this embodiment has a neutron generator 8 and γ-ray detection in order to obtain three-dimensional position information based on α particle detection inside the neutron generator 8 and γ-ray detection time by the γ-ray detector 10. Neither the vessel 10 needs to be a multidimensional array. Further, the closer the neutron generator 8 and the γ-ray detector 10 are to the object to be inspected, the better the detection efficiency, but there is no restriction on the positional relationship between them. Therefore, as shown in FIG. 2, the neutron CT can be installed in the same position as the X-ray imaging device in the moving direction of the inspection object, and the dimensions (particularly long) of the blasting object detection device A can be set. A great merit is obtained that the dimension in the vertical direction) can be reduced.
[0038]
≪Operation of explosives detection device≫
Next, operation | movement of the explosives detection apparatus A of one Embodiment is demonstrated with reference to FIGS. FIG. 5 is a processing flow of a portion related to the neutron CT of the explosives detection device of one embodiment.
[0039]
First, the operation of the X-ray imaging apparatus including the X-ray generator 5, the X-ray detector arrays 6, 7, etc. will be described.
In FIG. 1, explosives 2 are included in baggage 1. The baggage 1 is guided into the explosives detection device A by the transport means 3. The passage of the baggage on the transport means 3 is recognized by the explosives detection device A by the baggage detection sensor 21 using a laser. Inside the explosive detection device A, there are an X-ray generator 5 and X-ray detector arrays 6, 7. X-rays generated from the X generator 5 and transmitted through the baggage 1 are transferred to the X-ray detector array 6 or 6. It is detected by the X-ray detector array 7.
[0040]
In this embodiment, the X-ray detector arrays 6 and 7 are one-dimensional arrays, but a two-dimensional transmission image is obtained by the movement of the baggage 1 itself. Further, by operating the X-ray detector arrays 6 and 7 simultaneously, it is possible to obtain transmission images in two directions at the same time. The measurement signals (X-ray detection signals) of the X-ray detector arrays 6 and 7 are converted into image information by the X-ray detection signal processing device 11 and the image processing device 13a as described above and displayed on the display device 13b. (See FIG. 4).
[0041]
Next, the operation of the neutron CT including the neutron generator 8, the γ-ray detector 10, etc. will be described (see the flow in FIG. 5).
In FIG. 1, as in the case of the X-ray imaging apparatus, the baggage 1 is guided into the explosives detection apparatus A by the transport means 3, and the baggage 1 is recognized by the baggage detection sensor 21 using a laser. There is a neutron generator 8 and a γ-ray detector 10 inside the explosive detection device A, and α particles and neutrons are simultaneously generated from the target 15 by the fusion reaction (DT reaction) by deuterium ion irradiation (S1). Generate and fly in the opposite direction. Note that the flight direction of α particles (and neutrons) is isotropic, and all α particles flying from the relationship with the shape of the α ray detector 9 monitor the α particles (S2). Although not detected by 9, the flight direction of the corresponding neutron is immediately identified by the neutron CT signal processing device 12 when the α particle is detected.
[0042]
The neutron reacts with, for example, an element constituting the explosive 2 in the flight direction to generate γ rays (inelastic scattering (n, n ′) γ). Although γ rays are emitted isotropically, when γ rays are detected by the γ ray detector 10, the neutron CT signal processing device 12 identifies the flight time of neutrons (S3). If γ rays corresponding to the detected α particles are not detected within a predetermined time (including the case where the neutron passes through the baggage 1), the detection of the α particles is reset, and the corresponding α particles are detected. Detecting gamma rays.
[0043]
Next, an element that has reacted with neutrons is identified from the energy spectrum of γ rays (S4). Further, the position in the three-dimensional direction of the element that has reacted with the neutron is identified (S5). Further, by detecting a plurality of γ rays, a carbon / oxygen ratio, a nitrogen / oxygen ratio, and the like are calculated. Then, it is processed by the image processing device 13a and displayed on the display device 13b as shown in FIG.
[0044]
The display by the display device 13b will be described. The X-ray fluoroscopic images 13b1 and 13b2 are two-dimensional spatial distributions showing the difference in X-ray absorption rate by shading. The neutron CT image 13b3 displays the three-dimensional spatial distribution of the types of explosives identified by color classification based on the elemental composition ratio, that is, the composition ratio of carbon / oxygen and nitrogen / oxygen, or by comparison with a database. Further, the neutron CT image 13b3, which is a three-dimensional image, is numerically converted into a two-dimensional image having the same field of view as the X-ray fluoroscopic images 13b1 and 13b2, thereby obtaining a fluoroscopic image of the neutron CT. A composite image 13b4 obtained by superimposing the neutron CT image 13b3 and applying a filter such as edge enhancement is also displayed. The X-ray fluoroscopic images 13b1 and 13b2 are the same as the X-ray fluoroscopic images according to the prior art.
[0045]
That is, in the display device (image display device) 13b of this embodiment, the X-ray detection signal processing device 11, the neutron CT signal processing device 12, and the image processing device 13a process results of object transmission by the X-ray imaging device. Images (X-ray fluoroscopic images 13b1 and 13b2) and an object composition image (neutron CT image 13b3) by a neutron imaging device (neutron CT) are displayed. Further, as a processing result, the fluoroscopic image of the object by the X-ray imaging device and the composition image of the object by the neutron imaging device (neutron CT) are superimposed and synthesized on the display device 13b and displayed as a synthesized image 13b4.
[0046]
Conventionally, the concentration of at least two elements has been displayed as information from the neutron inquiry system and X-ray CT. However, explosives (drugs) are characterized by the element concentration ratio rather than the element concentration, that is, carbon / oxygen or nitrogen / oxygen, and the element detection does not improve the detection rate of explosives. However, in this embodiment, the shape and density image of the inspection object by the X-ray imaging apparatus and the composition image by the neutron CT are displayed individually or superimposed. Thereby, the operator's experience with the conventional X-ray imaging apparatus can be utilized, and at the same time, the presence of a dangerous substance can be impressed on the operator by the composition image. In addition, since the composition image is displayed with a composition ratio of carbon and nitrogen to oxygen, which is characteristic of explosives, explosives can be detected more reliably.
[0047]
Further, according to this embodiment, since the X-ray imaging device and the neutron CT can be installed at the same position (installed on the same plane (on the same cross section)) in the moving direction of the inspection object, the explosives inspection apparatus A Therefore, the explosives detection device A can be installed in a narrow place. Moreover, since the part of neutron CT (neutron generator 9 ...) can be reduced in size, the explosives detection apparatus A can also be reduced in size from this point. Further, since the portion of the neutron CT (neutron generator 9 ...) can be reduced in size, it becomes difficult to interfere with the X-ray imaging device (X-ray generator 5 ...), thereby facilitating the layout. Moreover, since it can be set as the structure which does not have the neutron detector which detects the neutron which reacted with the element and did not generate | occur | produce the gamma ray, the explosives detection apparatus A can be reduced in size also from this point.
[0048]
The present invention described above can be widely modified without being limited to the above-described embodiment. For example, as shown in FIG. 6, the explosives detection apparatus A (X-ray or neutron irradiation) may be operated based on a sequence. In this sequence, the movement of the baggage 1 by the transport means 3 is recognized by the explosives detection device A (control device not shown) by the baggage detection sensor 21. The irradiation time for one piece of baggage 1 is about 5 seconds. That is, if the size of the baggage 1 is about 1 m, the conveying speed of the conveying means 3 may be 0.2 m / s. X-ray and neutron irradiation starts before the baggage 1 reaches the cross section on which the X-ray generator 5 or the like shown in FIG. 2 is arranged (after two seconds detected by the sensor 21). X-ray and neutron irradiation may be performed continuously during the baggage inspection time or intermittently. X-ray, α-ray and γ-ray radiation measurement data processing and image updating can be performed at a cycle of several tens of Hz during baggage inspection.
[0049]
The explosive detection device can be installed at the entrance of a building or the like in addition to an airport. Moreover, although the object of the inspection has been described as an explosive, it can also be applied to the inspection / detection of chemical substances such as narcotics in animals and animals. In addition, any package can be inspected. In one embodiment, the X-ray imaging device (X-ray generator 5, X-ray detector array 6, 7) and neutron CT (neutron generator 8, γ-ray detector 10) are arranged in the same plane. Although the configuration is shown, it may be arranged so as to be shifted (offset) in the front-rear direction of the conveying means without departing from the spirit of the invention.
[0050]
【The invention's effect】
As described above, according to the luggage inspection apparatus of the present invention, Neutron CT identifies alpha particles flying in the opposite direction to the neutrons generated by the neutron generator using an alpha ray detector to identify the flight direction of the neutrons, and the detection of the alpha particles and the reaction of the neutrons with the elements By detecting the generated γ-rays with a γ-ray detector, the flight time of the neutron and the element that reacted with the neutron are identified, and the position of the element in the three-dimensional direction is further identified. Therefore, both the neutron generator and the γ-ray detector need not be multidimensionally arranged. Therefore, X-ray imaging device and neutron CT Transport In the direction On the same vertical section Therefore, the size of the luggage inspection device can be reduced. In addition, since the experience and knowledge of the operator in the conventional X-ray imaging apparatus can be used in the apparatus of the present invention, the usability of the operator is improved, for example, the detection rate of explosives and forbidden drugs is improved. To do. That is, the installation space can be reduced, and at the same time, the detection rate of explosives can be improved.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of an explosives detection device used for baggage inspection according to an embodiment of the present invention.
2 is a cross-sectional view showing an example of an arrangement structure of an X-ray generator, an X-ray detector array, a neutron generator, a γ-ray detector, etc. in the explosive detection device of FIG.
3 is a diagram illustrating a configuration example of a main part of a neutron CT in the explosive detection device of FIG. 1. FIG.
4 is a diagram showing a display example of a display device in the explosives detection device of FIG. 1. FIG.
5 is a processing flow of a portion related to neutron CT of the explosives detection apparatus of FIG.
FIG. 6 is an operation sequence diagram of the explosives detection device according to the embodiment.
[Explanation of symbols]
1 ... Baggage
2. Explosives
3 ... Feeding means
4 ... Equipment wall
5 ... X-ray generator
6,7 ... X-ray detector array
8 ... Neutron generator
9 ... α-ray detector array
l0 ... γ-ray detector
11 ... X-ray detection signal processing apparatus
12 ... Neutron CT signal processor
13a ... Image processing apparatus
13b ... Display device (image display device)

Claims (6)

An inspection apparatus for nondestructively inspecting the contents of a package, comprising an X-ray imaging device and a neutron CT , an X-ray generator and an X-ray detector of the X-ray imaging device , and a neutron of the neutron CT The generator and the γ-ray detector are arranged on the same cross section perpendicular to the carrying direction of the load, and the neutron CT emits α particles flying in the opposite direction to the neutrons generated by the neutron generator. The flight direction of the neutron is identified by detecting with a detector, and the flight time of the neutron is detected with the γ-ray detector by detecting the α particles and detecting γ rays generated by the reaction of the neutrons with the elements. And a neutron CT signal processing device that identifies the element that has reacted with the neutron and further identifies the position of the element in a three-dimensional direction . The luggage inspection apparatus includes an image display device connected to the X-ray imaging device and the neutron CT . The image display device includes a transmission image of the object by the X-ray imaging device and a composition image of the object by the neutron CT. The package inspection device according to claim 1 , wherein each of the items is displayed. In the cargo inspection system, the image display apparatus, and the object of the transmitted image obtained by the X-ray imaging apparatus, and displaying by combining the composition image of the object by the neutron CT, claim 1 or claim 2. The luggage inspection apparatus according to 2. In the cargo inspection system, the composition image of the object by the neutron CT is characterized in that a composition ratio information of three or more elements, baggage inspection apparatus according to claim 2 or claim 3. The luggage inspection apparatus according to claim 4 , wherein the three or more elements include oxygen, nitrogen, and carbon. The luggage inspection apparatus according to claim 1, wherein the γ-ray detector has an X-ray shield.

Images