JPH11202052A - Directional gamma-ray detection device and detection system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a high directivity by selectively detecting γ-rays arriving from a target even in a state of being surrounted by a γ-ray source. SOLUTION: A first radiation sensor 11 detects γ rays that has entered along a specific incidence direction with high sensitivity, a second radiation sensor 12 detects γ rays that are applied to the first radiation sensor 11 and are scattered forward, and an AND type data-processing device 14 detects that the detection by the first and second radiation sensors 11 and 12 has been simultaneously done.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a directional γ-ray detecting apparatus for providing directivity to γ-ray detection and measuring and detecting the arrival direction and source of radiation and a detection system using the same.

[0002]

2. Description of the Related Art Generally, when detecting gamma rays coming from an object, a directional gamma ray detection device having directivity for gamma ray detection is used by one of the following three methods. I have.

The first type of directional γ-ray detector uses a detector having a shape capable of improving the interaction between γ-rays and a substance in the direction of arrival of γ-rays.

FIG. 16 is a schematic diagram showing a configuration of a detector of such a directional γ-ray detecting device. This detector 1 has a diameter of 2r.
And a columnar (2r << L) sensitive portion having a length L several times that of the above, and can be easily manufactured using, for example, a plastic scintillator. Here, the interaction probability between the γ-ray and the substance is designed such that the absolute value of the diameter 2r is sufficiently shorter than the thickness of the half-value layer for the target γ-ray energy with respect to the γ-ray arriving perpendicular to the longitudinal direction. The length L is designed to be long and a sufficient value is secured for γ-rays arriving along the longitudinal direction while being kept low.

[0005] For example, in the case of a point source, the detector has a sufficiently high reaction rate because the transmission length is L for γ-rays incident from the front at an angle of 0 °. On the other hand, the response rate is low because the transmission length is 2r when the light is incident from the front at 90 degrees. As described above, in the first method, a shape corresponding to the arrival direction of the γ-ray is provided, and the detection sensitivity in the 0-degree direction is relatively improved as compared with the detection sensitivity in the 90-degree direction.

[0006] The directional γ-ray detecting device of the second system is shown in FIG.
As shown in FIG. 7, a switch type detector 2 is used. The Woswitch-type detector 2 has a structure in which a first scintillator 3 and a second scintillator 4 are stacked in two layers and are closely attached to a photocathode of a photomultiplier tube 5. Here, the scintillators 3 and 4 are combinations having different light emission waveforms (light emission decay times). In other words, when the light emission from the two scintillators 3 and 4 is identified by the measurement of the light emission waveform, the γ-rays do not enter from the side surfaces of the scintillators 3 and 4 but enter from the first scintillator 3 side. It is determined that it has been done.

A directional γ-ray detector of the third type uses a taper collimator 6 as shown in FIG. 18, for example, to provide a focusing function in addition to a function of measuring the arrival direction of γ-rays. The tapered collimator 6 has a tapered conical shape, and is installed in front of a scintillation detector in which a large scintillator 7 and a photomultiplier tube 8 at the subsequent stage are combined.

Here, γ coming from the source at the focal point f
The line easily passes through the tapered portion of the tapered collimator 6 and reaches the scintillator 7. On the other hand, γ-rays arriving from a position outside the focal point f are unlikely to reach the scintillator 7. In addition, such a method of giving directivity is used in medical scintillation cameras and the like.

[0009]

However, in the above-described directional γ-ray detecting apparatus, there are problems in each of the first to third systems as described below.

In the case of the first method, in a state surrounded by a γ-ray source, the state is equivalent to a state in which a parallel flux is uniformly incident from the lateral direction regardless of the angle, and the directivity is weakened.
For example, in the 0-degree direction, since the area of the incident surface is small instead of having a long transmission thickness of the length L, the detection efficiency is reduced. On the other hand, the length 2
Since the length L of the incident surface is long instead of having a short transmission thickness of r, the detection efficiency is geometrically improved. Thus, in the background state surrounded by the γ-ray source, there is a problem that the directivity in the 0-degree direction is reduced.

In the case of the second system, since Compton scattered γ-rays of various angles in the first scintillator 3 are detected, it is basically difficult to realize sharp directivity. Further, in addition to a normal circuit such as a preamplifier and a signal detection circuit, a complicated additional circuit for analyzing a pulse waveform is required, so that there is a problem that the cost increases.

In the case of the third method, although simple and reliable, the whole apparatus is large and heavy. For this reason, it is suitable for a stationary type device, but is not suitable for a portable type device which can be installed at an arbitrary place.

The present invention has been made in view of the above-described circumstances, and can selectively detect γ-rays coming from an object even in a state surrounded by a γ-ray source, thereby achieving high directivity. An object of the present invention is to provide a directional γ-ray detection device that can be realized and a detection system using the same.

It is another object of the present invention to provide a directional γ-ray detecting apparatus which can easily realize sharp directivity in principle and which can be realized at low cost, and a detection system using the same. It is in.

Still another object of the present invention is to provide a directional γ-ray detecting device which can be easily installed at an arbitrary place, and a detecting system using the same.

[0016]

The gist of the present invention is that the two radiation sensors are arranged in the direction of arrival of the γ-rays, and the γ-ray detection is effective only when the γ-rays are detected simultaneously by both the radiation sensors. The purpose is to easily realize directivity.

This type can be realized at low cost because a complicated circuit for waveform analysis is not required. Further, since a large-sized member such as a tapered collimator is not required, it can be easily installed at an arbitrary place. Further, it goes without saying that the shape, arrangement position, presence or absence of directivity, and the like of each radiation sensor are arbitrary.

Now, based on the gist of the present invention as described above, the following means are specifically taken. An invention corresponding to claim 1 is a first radiation sensor having directivity for detecting γ-rays incident along a predetermined incident direction with higher sensitivity than γ-rays incident from other directions, and the first radiation sensor. A second radiation sensor that is disposed behind the radiation sensor and detects a forward scattered component of Compton-scattered γ-rays incident on the first radiation sensor, and detection by the first and second radiation sensors. This is a directional γ-ray detection device provided with a simultaneity detecting means for detecting the simultaneousness.

According to a second aspect of the present invention, in the directional γ-ray detecting device according to the first aspect, the second radiation sensor includes a γ-ray incident from a direction in which the first radiation sensor is arranged. This is a directional γ-ray detection device having directivity for detecting a line with higher sensitivity than γ-ray incident from another direction.

Further, according to a third aspect of the present invention, in the directional γ-ray detecting apparatus according to the first or second aspect, one or both of the radiation sensors are γ-ray detectors.
A directional γ-ray detection device includes a scintillator that generates light due to incidence of a line, and an optical waveguide that collects light in the scintillator and provides the same to a subsequent-stage simultaneousness detection unit.

According to a fourth aspect of the present invention, there is provided a directional γ-ray detecting apparatus according to any one of the first to third aspects, wherein the γ-ray detecting apparatus is disposed near the first radiation sensor, A photographing means for photographing a visible image in a direction of arrival of a ray; an indication of a direction of arrival of the gamma ray obtained based on the directivity of the first radiation sensor; and a visible image photographed by the photographing means. This is a directional γ-ray detection device including an image synthesizing unit.

According to a fifth aspect of the present invention, there is provided a directional γ-ray detecting system using the directional γ-ray detecting device according to any one of the first to third aspects, wherein the directional γ A plurality of line detection devices are arranged, a simultaneous detection addition unit that adds together the synchronization detection signals output from the respective directional γ-ray detection devices, and outputs an addition result, and the directional γ-rays. A directional γ-ray detection system comprising: an arrangement direction changing unit for individually changing the arrangement direction of the detection device. The invention corresponding to claim 6 has ring shapes having different radii from each other, and Detects that the first and second radiation sensors for detecting incident γ-rays and the first and second radiation sensors are at the same time. Simultaneous detection means A directional γ ray detection device provided.

Further, the invention according to claim 7 is the directional γ-ray detection device according to claim 6, wherein the first
And the second radiation sensors have the same number of arc detection units each having the same number and a fixed length, and the synchronization detecting means detects that the detections are simultaneously performed with respect to the sets of the detection units having the same relative positions. It is a directional γ-ray detector.

According to an eighth aspect of the present invention, there is provided a plurality of detectors arranged in a plane and opposed to each other in a parallel plate shape, and the incident γ-rays are individually detected by the respective detectors. When each of the first and second radiation sensors, the detection unit in the first radiation sensor, and the detection unit in the second radiation sensor detect γ-rays, each of the detections was performed simultaneously. Γ incident from a predetermined incident direction on the set of parts
Determine whether or not a predetermined set along the incident path of the line,
A directional γ-ray detection device comprising: a combination determination unit that validates a detection result of a predetermined set.

According to a ninth aspect of the present invention, there is provided a directional γ-ray detecting apparatus according to any one of the sixth to eighth aspects, wherein the directional γ-ray detecting apparatus is disposed near the first radiation sensor, A photographing means for photographing a visible image in a direction of arrival of a ray; an indication of a direction of arrival of the gamma ray obtained based on the directivity of the first radiation sensor; and a visible image photographed by the photographing means. This is a directional γ-ray detection device including an image synthesizing unit.

According to a tenth aspect of the present invention, in the directional γ-ray detecting apparatus according to the ninth aspect, the first
A distance measuring unit disposed near the radiation sensor for measuring the focal length of the visible image, and calculating a surface dose rate at a focal position of the visible image based on the focal length measured by the distance measuring unit. A directional γ-ray detection device comprising: a dose rate calculating unit; and a calculation result sending unit that sends the calculation result to the image synthesizing unit so as to display a calculation result by the dose rate calculating unit.

According to an eleventh aspect of the present invention, in the directional γ-ray detection system according to the fifth aspect, the mutual arrangement direction of each directional γ-ray detection device is controlled by the arrangement direction changing means. Scanning the focus positions realized by individually changing, scanning measurement means for recording the measurement data of γ-rays at each focus position, based on each measurement data and scan content obtained by the scan measurement means, A directional γ-ray detection system including a map creating unit that creates a map of measurement results.

According to a twelfth aspect of the present invention, in the directional γ-ray detecting apparatus according to any one of the sixth to eighth aspects, a relative distance between the first and second radiation sensors is provided. Distance changing means for moving any one of the radiation sensors so as to change the distance, and eccentricity for moving any one of the radiation sensors so as to decenter the central axes of the rings of the first and second radiation sensors. Control means, by controlling the distance change means and the eccentricity control means, scans the focal position realized by changing the relative arrangement of each radiation sensor, and measures the γ-ray measurement data at each focal position Directivity γ comprising scanning measurement means for recording, and map creation means for creating a map of each measurement result based on each measurement data and scan content obtained by the scanning measurement means.
It is a line detection device.

According to a thirteenth aspect of the present invention, in the directional γ-ray detecting apparatus according to the eighth aspect, a combination changing means for changing a set of each detection unit of the first and second radiation sensors. By controlling the combination change means, scans the focal position realized by changing the set of each of the detection units, scan measurement means for recording the measurement data of γ-rays at each focus position, and the scan measurement means A directional γ-ray detection device comprising: a map creating unit that creates a map of each measurement result based on each of the obtained measurement data and scan contents.

(Operation) Therefore, in the invention corresponding to claim 1, by taking the above means, the first radiation sensor detects the γ-ray incident along a predetermined incident direction with high sensitivity. Then, the second radiation sensor detects gamma rays incident on the first radiation sensor and scattered forward, and the synchronization detecting means detects that the detections by the first and second radiation sensors are simultaneous. Therefore, even in a state surrounded by a γ-ray source, γ-rays arriving from an object in a predetermined incident direction can be selectively detected, and high directivity can be realized.

In addition, since the two radiation sensors in the incident direction are simultaneously detected, sharp directivity can be easily realized in principle, and a complicated circuit for waveform analysis or the like is not required, thereby reducing cost. In addition, since a large-sized member such as a tapered collimator is not required, it can be easily installed at an arbitrary place.

According to a second aspect of the present invention, the second radiation sensor has a directivity having a high detection sensitivity in the direction in which the first radiation sensor is arranged. In addition, sharper directivity can be realized.

According to a third aspect of the present invention, in one or both of the radiation sensors, the scintillator generates light due to the incidence of γ-rays, and the optical waveguide collects the light in the scintillator. Since this is applied to the later-stage simultaneousness detection means, in addition to the action corresponding to claim 1 or claim 2, an extra scatterer between the two radiation sensors can be eliminated, and the detection sensitivity can be improved. .

According to a fourth aspect of the present invention, the imaging means captures a visible image in the arriving direction of the γ-ray, and the image synthesizing means obtains the γ-ray obtained based on the directivity of the first radiation sensor. Is combined with the visible image photographed by the photographing means, so that the visible image of the γ-ray source can be visually recognized in addition to the operation of any one of claims 1 to 3.

According to a fifth aspect of the present invention, a plurality of directional γ-ray detectors are used, and the simultaneous detection and addition means adds together the synchronous detection signals output from the respective directional γ-ray detectors. Then, the addition result is output, and the arrangement direction changing means individually changes the arrangement direction of each directional γ-ray detection device, so that in addition to the operation of any one of claims 1 to 3,
By intersecting the arrival direction of γ-rays expected by each directional γ-ray detection device at an arbitrary position in space, γ-rays arriving from any position in space can be detected with high sensitivity, and thus spatially Can also improve the directivity.

According to a sixth aspect of the present invention, the first and second radiation sensors are arranged to face each other so as to be parallel to each other to detect γ-rays respectively, and the synchronism detecting means comprises each radiation sensor. Is detected at the same time, even in the state of being surrounded by the γ-ray source, the incident light from the γ-ray source located at the apex of the cone including the ring-shaped first and second radiation sensors Γ-rays can be selectively detected, thereby realizing high directivity.

Further, similarly to the above, sharp directivity can be easily realized in principle, can be realized at low cost, and can be easily installed at any place.

According to a seventh aspect of the present invention, each of the ring-shaped first and second radiation sensors detects each gamma ray in each of the arc-shaped detection units, and the synchronism detection means sets the relative position equal to each other. Since the simultaneous detection is detected for the set of position detection units, in addition to the operation corresponding to claim 6, it is possible to reduce a detection error due to coincidence detection that occurs by chance and improve reliability.

According to an eighth aspect of the present invention, in the first and second radiation sensors, a plurality of detectors arranged in a plane detect γ rays individually, and 1
When the detection unit in the radiation sensor and the detection unit in the second radiation sensor respectively detect γ-rays, the detection unit detects the γ-rays incident from a predetermined incident direction with respect to each set of detection units that were detected simultaneously. It is determined whether or not it is a predetermined pair along the incident path, and the detection result by the predetermined pair is validated. Therefore, even in a state surrounded by a γ-ray source, a cone including each detection unit pair Γ-rays incident from a γ-ray source located at the vertex of the shape can be selectively detected, and thus high directivity can be realized. In addition, similarly to the above, sharp directivity can be easily realized in principle, can be realized at low cost, and can be easily installed at any place.

Further, according to a ninth aspect of the present invention, the imaging means captures a visible image in the arrival direction of the γ-ray, and the image synthesizing means obtains the γ-ray obtained based on the directivity of the first radiation sensor. Is combined with the visible image photographed by the photographing means, so that the visible image of the γ-ray source can be visually recognized in addition to the function of any of claims 6 to 8.

According to a tenth aspect of the present invention, the distance measuring means measures the focal length of the visible image, and the dose rate calculating means measures the focal length of the visible image based on the focal length measured by the distance measuring means. The surface dose rate at the focal position is calculated, and the calculation result sending unit sends the calculation result by the dose rate calculation unit to the image synthesizing unit so as to display the calculation result. Even when the focus is not on the surface of the object, that is, different from the focus of the visible image, the detection result of the γ-rays by both radiation sensors can be converted into the surface dose rate of the captured object.

Further, according to an eleventh aspect of the present invention, the scanning measurement means controls the focal position realized by individually changing the mutual arrangement directions of the directional γ-ray detection devices under the control of the arrangement direction changing means. Scanning, record the measurement data of γ-rays at each focal position, and map creating means creates a map of each measurement result based on each measurement data and scanning content obtained by the scanning measuring means. In addition to the operation corresponding to the item 5, the γ-ray intensity distribution in the space can be measured, and the measurement result can be shown by mapping.

According to a twelfth aspect of the invention, the distance changing means moves one of the radiation sensors so as to change the relative distance between the first and second radiation sensors, and , One of the first and second radiation sensors is moved so as to decenter the center axis of the other ring, and the scanning measuring means is controlled by the distance changing means and the eccentricity controlling means to control each radiation. Scan the focal position realized by changing the relative arrangement of the sensors, record the measurement data of γ-rays at each focal position, and map creation means, each measurement data obtained by the scanning measurement means and the scanning content Create a map of each measurement result based on the
In addition to the actions corresponding to any one of claims 6 to 8, it is possible to measure the γ-ray intensity distribution in space and to show the measurement results in a map form.

Further, according to a thirteenth aspect of the present invention, the scanning measuring means scans a focal position realized by changing a set of each detecting section under the control of the combination changing means, and performs γ-ray irradiation at each focal position. Record the measurement data of
Since a map of each measurement result is created based on each measurement data and scan content obtained by the scan measurement means, in addition to the action corresponding to claim 8, the radiation sensor is not driven mechanically in space. Γ-ray intensity distribution can be measured, and the measurement results can be shown in a map form.

[0045]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a schematic diagram showing a configuration of a directional γ-ray detecting device according to a first embodiment of the present invention. The directional γ-ray detection device 10 includes a first radiation sensor 11, a second radiation sensor 12 disposed behind the first radiation sensor 11, and each radiation sensor 1.
Electronic circuits 13 ₁ , 13 individually connected to
₂ and a logical product data processing device 14 capable of counting the logical product of the outputs of the electronic circuits 13 ₁ and 13 ₂ .

Here, the first radiation sensor 11 corresponds to FIG.
As shown by a solid line, the directional characteristic has a directivity of detecting γ-rays incident along the 0-degree direction on the front with higher sensitivity than γ-rays incident from other directions. it is intended to provide a first electronic circuit 13 _1.

The first radiation sensor 11 is designed to have a relatively high γ-ray detection sensitivity in the forward direction by the first method of the prior art or the like. For example, as the first radiation sensor 11, a gas-filled type or scintillation detector having a sufficiently long length L with respect to the diameter 2r of the sensor can be used. In addition, a thin semiconductor detector or the like with a small shield can be applied.

The second radiation sensor 12 has no directivity, as indicated by the broken line in FIG. The second radiation sensor 12 is arranged so as to be able to detect a forward scatter component in the 0-degree direction of γ-rays that are incident on the first radiation sensor 11 and are Compton-scattered. When the forward scatter component is detected, a detection signal is output. the one that confers a second electronic circuit 13 _2.

For example, as the second radiation sensor 12, in addition to a gas-filled type or a scintillation detector, Cd
Semiconductor detectors having sensitivity to γ rays, such as Te and photodiodes, can be applied.

The first and second electronic circuits 13 ₁ , 13
Reference numeral ₂ denotes a well-known photoelectric conversion circuit provided independently of each other, including a preamplifier and a converter to an electric signal corresponding to the type of each radiation sensor, and other circuits required for signal detection and amplification are applied. It is possible. When each electronic circuit individually receives a detection signal such as a light pulse from each radiation sensor, it performs photoelectric conversion and provides an output of an electric signal to the logical product data processing device 14.

The logical product type data processing device 14 has a function of performing simultaneous counting processing on the outputs of the electronic circuits 13 ₁ and 13 ₂ to calculate γ-ray intensity and the like.

Next, the operation of such a directional γ-ray detector will be described. At the site of a nuclear power plant or the like, γ-rays radiated from equipment are usually 100 keV to 2 MeV
It is about. The γ-rays in this energy region enter the first radiation sensor 11 and are detected, and a detection signal is given to the _first electronic circuit 131. On the other hand, with high probability, the forward scatter component of Compton scattering in the incident direction At around 0 degrees.

The emitted forward scattered component enters the second radiation sensor 12 and is detected, and a detection signal is given to the _second electronic circuit 132.

First and second electronic circuits 13 ₁ , 13
₂ converts the detection signals into electric signals and outputs the electric signals to the logical product data processing device 14.

The logical product type data processing device 14 counts the outputs of the electronic circuits 13 ₁ and 13 ₂ simultaneously to obtain 0
The gamma rays incident from the degree direction are recognized, and the gamma ray intensity is calculated.

As described above, according to the present embodiment, the first
Of the gamma ray incident along a predetermined incident direction with high sensitivity, the second radiation sensor 12
The gamma ray incident on the first radiation sensor 11 and scattered forward is detected, and the logical product type data processing device 14
Of the radiation sensors 11 and 12 at the same time, it is possible to selectively detect γ-rays coming from an object in a predetermined incident direction even in a state surrounded by a γ-ray source. As a result, high directivity can be realized.

Also, two radiation sensors 1 in the incident direction
Because of the configuration for simultaneous detection of 1 and 12, sharp directivity can be easily realized in principle, and a complicated circuit such as a waveform analyzer can be realized at a low cost without being required. Since large members such as are unnecessary, it can be easily installed at an arbitrary place.

(Second Embodiment) FIG. 3 is a schematic diagram showing the configuration of a directional γ-ray detecting device according to a second embodiment of the present invention. Elements similar to those in FIG. The detailed description is omitted, and only different parts are described here. In the following respective embodiments, the duplicated description will be omitted in the same manner.

That is, the directional γ-ray detector 10a according to the present embodiment is a modification of the first embodiment, and achieves a sharper directivity. The radiation sensor 12a has directivity similarly to the first radiation sensor 11.

More specifically, the second radiation sensor 12a
Like the solid line in FIG. 2, it has directivity for detecting γ-rays incident from the direction in which the first radiation sensor 11 is arranged with higher sensitivity than γ-rays incident from other directions.

With such a structure, in the second radiation sensor 12a, the forward scatter component received from the first radiation sensor 11 is detected with high sensitivity, and the γ-ray received from directions other than the incident direction is detected with low sensitivity. Removed. Therefore, the detection range of the forward scatter component can be narrowed, and although the detection probability decreases, sharper directivity can be realized.

(Third Embodiment) FIG. 4 is a schematic diagram showing a configuration of a directional γ-ray detecting device according to a third embodiment of the present invention, and FIG. 5 is applied to this directional γ-ray detecting device. 1 is a schematic diagram showing a cross-sectional configuration of a radiation sensor to be used.

That is, the directional γ-ray detector 10b
Is a specific example of the first or second embodiment, which aims to improve the detection sensitivity by eliminating extra γ-ray scatterers between the radiation sensors 11 and 12. Specifically, FIG.
As shown in (a), each of the radiation sensors 11 and 12 has a scintillator 2 that generates light due to incidence of γ-rays.
And 1, 22, succeeding electronic circuits ₁₃ 1 condenses the light in the scintillator 21, 13 wavelength shifting fiber (optical _waveguide) for providing a ₂ 23 1, and 23 ₂ provided respectively. Note that the optical waveguide is a wavelength-shifted fiber 23 ₁ ,
Is not limited to the optical fiber 23 _2, etc., it may be a light pipe or the like.

More specifically, each of the scintillators 21 and 22
A reflector 24 is applied to the outside, and is housed in a case 25 in close contact with each other. Case 25 has a light shielding function, the first and second optical connectors 26 _1, 26 ₂ is fixed to the end portion of the second scintillator 22 side of the subsequent stage.
Note that the scintillators 21 and 22 are optically disconnected by the reflector 24.

[0066] Each scintillator 21 and 22, respectively wavelength shifting fiber ₂₃ 1, 23 ₂ is inserted to the inside so as not to protrude its tip. Each wavelength shifting fibers 23 _1, 23 ₂ absorbs the scintillation light, and transmit to the proximal end face to emit light of longer wavelength inside.

[0067] The first wavelength shifting fibers 23 _1, tip specular reflector 27 ₁ for improving light collection efficiency is formed in close contact by the first optical connector proximal end through the second scintillator 22 It is attached to the case 25. In addition,
First wavelength shifting fibers 23 _1, the light blocking layer 28 is formed on the outer peripheral region located in the second scintillator 22,
The absorption of the scintillation light of the second scintillator 22 is prevented.

[0068] ₂ second wavelength shifting fibers 23 is similar to that described above specular reflector 27 ₂ adhesion formation at the tip, the proximal end is attached to the case 25 by the second optical connector 26 _2.

The first and second optical connectors 26 ₁ , 26 ₂
One end of the optical fiber 29 _1, 29 ₂ for transmission is mounted detachably from the outside. Each optical fiber 29 ₁ ,
29 ₂ at the other end is connected to each electronic circuit ₁₃ 1, 13 _2.

The electronic circuits 13 ₁ and 13 ₂ correspond to the optical fiber 2
9 _1, 29 light pulses transmitted from the ₂ is intended to be converted to an electrical signal that can be processed by logical data processing unit 14, for example, a photomultiplier tube for converting light into an electric signal,
Known circuits including a photoelectric conversion element such as a photodiode, an amplifier, a signal detection circuit, and the like can be applied.

Next, the operation of such a directional γ-ray detecting device will be described. Now, a first scintillator 21 is used for the first radiation sensor 11 and a second radiation sensor 12 is used.
A second scintillator 22 is used, and both scintillators 21 and 22 are arranged in close contact with each other while being shielded from light.

Here, it is assumed that γ rays are incident on the first scintillator 21. The first scintillator 21 generates scintillation light due to the incidence of γ-rays,
The forward scattered component of the Compton-scattered γ-ray is emitted toward the second scintillator 22.

Similarly, the second scintillator 22 generates scintillation light due to the incidence of the forward scattered component of the γ-ray.

The scintillation light in each of the scintillators 21 and 22 is individually converted into wavelength-shifted fibers 23 ₁ and 23 _2.
And is converted into a long-wavelength light pulse. Each light pulse optical connector ₂₆ 1, 26 ₂ and the optical fiber ₂₉ 1,
29 ₂ via the read onto the electronic circuit ₁₃ 1, 13 _2, as described above, it is treated coincidence.

As described above, according to the present embodiment, the first
And a second radiation sensors 11 and 12 using a scintillator 21, is arranged close to the two scintillators 21, 22, ₂₃ 1, 23 _2, etc. wavelength shifting fibers individually scintillation light in the scintillators 21 and 22 Since reading is performed by the optical waveguide, an extra scatterer can be eliminated from between each of the scintillators 21 and 22, and the detection sensitivity can be improved.

To supplement, the second radiation sensor 12
Compton scattering γ incident from the first radiation sensor 11
Since it detects a ray, it is preferable that a substance serving as a γ-ray scatterer is not interposed between the first and second radiation sensors 11 and 12 as much as possible. In the present embodiment, the structure in which the two scintillators 21 and 22 are in close contact with each other prevents the interposition of the γ-ray scatterer between the radiation sensors 11 and 12.

Further, unlike the conventional case, the scintillation light is not directly received by the photomultiplier tube or the like, so that the light can be read out completely independently, and the measurement accuracy is expected to be improved. Can be.

This embodiment can be applied to both the first and second embodiments, and it is needless to say that the effects of the corresponding embodiments can be obtained.

In this embodiment, as shown in FIG. 5B, the directivity can be improved by deforming the first scintillator 21 into a conical shape. At this time, since the γ-rays received by the second scintillator 22 are lower than the γ-rays received by the first scintillator 21, the length of the second scintillator 22 can be shorter than that of the first scintillator 21.

(Fourth Embodiment) FIG. 6 is a schematic diagram showing a configuration of a directional γ-ray detection system according to a fourth embodiment of the present invention. This directional γ-ray detection system may be any directional γ-ray detection device 10 of the first to third embodiments.
i (10, 10a, 10b), a camera 31 arranged near the directional γ-ray detecting device 10i, and an imaging device 32 for combining both outputs of the directional γ-ray detecting device and the camera.
And a display device 33 for displaying the result of the synthesis by the imaging device 32.

Here, the camera 31 is arranged, for example, as close as possible to the first radiation sensor 11 and has a function of photographing a visible image of a visual field including the arrival direction of γ-rays, and shows the photographing result. It has a function of transmitting a video signal to the imaging device 32.

The imaging device 32 includes the first radiation sensor 1
1 for synthesizing an indication of the arrival direction of γ-rays obtained based on the directivity and a visible image captured by the camera 31, and optionally measuring the γ-ray intensity received from the directional γ-ray detection device 10i. It also has the function of combining the result with the visible image.

Although not shown, the imaging device 32 may include a recording unit, an external control unit, a data transfer unit, and the like, if desired.

Next, the operation of such a directional γ-ray detection system will be described. In the directional γ-ray detection device 10i, the first and second radiation sensors 11 and 12 are arranged along the expected direction of arrival of γ-rays. In addition, the camera 31 captures a visual field range including the expected direction of arrival of the γ-ray.

Here, the directional γ-ray detector 10 i
The coincidence counting result as the line detection result is sent from the logical product type data processing device 14 to the imaging device 32. Further, the camera 31 sends the photographing result to the imaging device 32.

The imaging device 32 indicates an expected direction of arrival of the γ-ray, a visible image obtained from the photographing result received from the camera 32, and a measurement of the γ-ray intensity received from the directional γ-ray detecting device 10i. The result is synthesized, a display image such as a mark indicating the arrival direction of γ-rays is added to the visible image, and γ-ray intensity information is added to create a display image.

The display device 33 displays this display image. As described above, according to the present embodiment, the camera 31 captures a visible image in the direction of arrival of γ-rays,
Combines the indication of the arrival direction of the γ-rays obtained based on the directivity of the first radiation sensor 11 and the visible image captured by the camera 32, so that any of the first to third embodiments is applicable. In addition to the effect of the directional γ-ray detection device 10i, a visible image of the γ-ray source can be visually recognized. Further, if desired, a visible image to which γ-ray intensity information or the like is added can be visually recognized.

(Fifth Embodiment) FIG. 7 is a schematic diagram showing the configuration of a directional γ-ray detection system according to a fifth embodiment of the present invention. To this directional γ-ray detection system, two directional γ-ray detection devices 10i of any mode in the first to third embodiments are applied.

Each directional γ-ray detecting device 10i is arranged along a substantially V-shaped side having a vertex (or a focal point f) at a predetermined position in order to detect γ-rays arriving from a predetermined position. The sensing surfaces or the directions having directivity are arranged so as to see the same focal point f in space. When the source is located at a point f where the lines indicating the directions of arrival identified by the plurality of directional γ-ray detectors 10i intersect, the γ-rays emitted from the source are not included in any of the directional γ-ray detectors 10i. Is also reachable. Therefore, this point f corresponds to the focal point f in a general lens system, and is referred to as the focal point f in this specification.

The outputs of the directional γ-ray detectors 10i are sent to the OR-type data processor 34, respectively.

The logical sum type data processing device 34 performs a counting process by adding the logical sum of the outputs of the two directional γ-ray detecting devices 10i.

Further, the arrangement direction of each directional γ-ray detection device 10i can be changed by an arrangement direction changing unit (not shown). For example, when the arrangement direction is set from the outside, the arrangement direction changing unit rotates one or both of the directional γ-ray detection devices 10i based on the setting contents, and sets the directional γ-ray detection device 10i. This is to change the arrangement direction.

Next, the operation of such a directional γ-ray detection system will be described. Two directional γ-ray detectors 10i
Detects γ-rays arriving from the position of the focal point f, and sends a detection signal to the logical sum type data processing device 34. The OR-type data processing device 34 includes the directional γ-ray detection devices 10i.
, And outputs the added result by adding together the detection signals sent from the respective devices.

As described above, since the two directional γ-ray detectors 10i detect γ-rays for one γ-ray source (focal point f), the sensitivity can be relatively improved.

Further, since the arrangement direction changing unit individually changes the arrangement direction of each directional γ-ray detection device 10i based on, for example, the setting operation of the operator, it is possible to change the position of the focal point f to be measured. it can.

As described above, according to the present embodiment, the first
In addition to the effects of any one of the third to third embodiments, the arrival directions of the γ-rays projected by the two directional γ-ray detectors 10i intersect at an arbitrary position in the space, so that an arbitrary position in the space is obtained. Γ-rays coming from
Directivity can be improved spatially.

The number of directional γ-ray detectors 10i is not limited to two, and any number can be used, and the detection sensitivity can be improved in proportion to the number of used γ-ray detectors.

(Sixth Embodiment) FIG. 8 is a schematic diagram showing a configuration of a directional γ-ray detecting device according to a sixth embodiment of the present invention. This directional γ-ray detection device is a modification of the first embodiment, and aims to improve the directivity for detecting γ-rays coming from an arbitrary focal point f in space.
Specifically, as shown in FIG. 8, first and second rings having ring shapes having different radii are arranged so as to be spaced apart from each other so that the rings are parallel to each other, and detect incident γ-rays. Radiation sensors 41 and 42 are provided. Note that the subsequent stage of each of the radiation sensors 41 and 42 is connected to the logical product data processing device 14 via each of the electronic circuits 13 ₁ and 13 ₂ as described above.

Here, the first radiation sensor 41 is
And has a smaller diameter than that of the radiation sensor 42, and is disposed at the front stage, and does not have directivity of γ-ray detection. The second radiation sensor 42 has a larger diameter than the first radiation sensor 41, and similarly has no directivity for γ-ray detection.

The radiation sensors 41 and 42 are arranged at a distance L so that the center axes of the rings overlap each other. The position of the vertex of the cone including the ring-shaped radiation sensors 41 and 42 corresponds to the effective focal point f.
The electronic circuits 13 ₁ and 13 ₂ and the logical product data processing device 14 are the same as those described above.

Next, the operation of such a directional γ-ray detecting device will be described. As described above, in the case of γ-rays having an energy of 100 keV or more, the forward scatter component of Compton scattering is emitted with a high probability near 0 ° from the incident direction. That is, the γ-rays emitted from near the focal point f
And the forward scatter component is incident on the second radiation sensor 42 with a high probability.

On the other hand, γ radiated from other than the vicinity of the focal point f
Even if the line enters the first radiation sensor 41 and is scattered forward, it does not enter the second radiation sensor 42.

For this reason, the outputs of the ring-shaped radiation detection sensors 41 and 42 are simultaneously counted to obtain the focal point f.
Γ-rays from the vicinity can be detected with relatively high sensitivity.

As described above, according to the present embodiment, the first
And the second radiation sensors 41 and 42 are arranged to face each other so as to be parallel to each other to detect γ-rays, respectively, and the logical product data processing device 14 causes the radiation sensors 41 and 42 via the electronic circuits 13 ₁ and 13 _2. , 42 are detected at the same time, so that they are located at the vertices of a cone including the ring-shaped first and second radiation sensors 41, 42 even in a state surrounded by a γ-ray source. γ-rays incident from a γ-ray source can be selectively detected, and thus high directivity can be realized.

Further, similarly to the above, sharp directivity can be easily realized in principle, can be realized at low cost, and can be easily installed at any place.

(Seventh Embodiment) FIG. 9 is a schematic diagram showing a configuration of a directional γ-ray detecting apparatus according to a seventh embodiment of the present invention. This directional γ-ray detection device is a modification of the sixth embodiment, and includes first and second radiation sensors 41s and 42s.
s is the same number as each other and each is a fixed length arc-shaped detection unit 41
a to 41f and 42a to 42f. The arrangement of the radiation sensors 41s and 42s is the sixth.
This is the same as the embodiment.

The detecting units 41 having the same relative position
For each set a, b,..., f of a to 41f, 42a to 42f,
The logical product type data processing device 14 is connected via electronic circuits 13 ₁ and 13 ₂ . Each logical product type data processing device 1
4 is connected to the input of the logical sum type data processing device 34. Here, the first radiation sensor 41s is configured as shown in FIG.
As shown in (a), the inside of the small-diameter ring is composed of six detectors 41a to 41f divided into six segments.
Each of the detection units 41a to 41f individually detects γ-rays, and FIG.
(B), the has a function of transmitting a detection signal to the first electronic circuit 13 ₁ separately.

Similarly, as shown in FIG. 9A, the second radiation sensor 42s is composed of six detectors 42a to 42f in which the inside of the large-diameter ring is divided into six segments. detects γ rays individually, as shown in FIG. 9 (b), has a function of transmitting a detection signal to the ₂ second electronic circuit 13 separately. Note that the first and second radiation sensors 41s and 42s may be modified to have any other number of detection units as long as they have the same number.

First and second electronic circuits 13 ₁ , 13
₂ are the detection units 41a to 41 at the same relative positions.
f, 42 a to 42 f, each having a function such as the above-described photoelectric conversion, and individually sending outputs to the logical product data processing device 14.

The logical product type data processing device 14 comprises detecting units 41a to 41f, 42a to 4
It is provided for each set of 2f and has a function such as the coincidence counting described above, and sends its output to the logical sum type data processing device 34, respectively.

The logical sum type data processing device 34 includes the sets a to f
It has a function of adding and counting outputs received from the six AND-type data processing devices 14 to 14.

Next, the operation of such a directional γ-ray detecting device will be described. The γ-ray emitted from near the focal point f is the first
And the forward scatter component is incident on the second radiation sensor 42s with high probability. For more information,
The γ-ray arriving from the focal point f is incident on the first and second radiation sensors 41s and 42s at the same relative position.

On the other hand, γ radiated from other than near the focal point f
Even if the line enters the first radiation sensor 41s and scatters forward, the line does not enter the second radiation sensor 42s.

However, the first and second radiation sensors 41
Depending on the dimensions and the positional relationship of s and 42s, there is a possibility that γ-rays scattered from the first radiation sensor 41s other than near 0 degrees and accidentally enter the second radiation sensor 42s exist.

Here, in the directional γ-ray detecting apparatus according to the present embodiment, each of the detectors 41a to 41f having six ring shapes is used.
Since the detection results of the sets a to f of the detection units 41a to 41f and 42a to 42f which are formed from the detection units 41a to 41f and are located at the same relative positions are simultaneously counted, the γ-ray incident accidentally as described above is also detected from the detection results. It can be removed, and the coincidence coincidence component can be reduced.

As described above, according to the present embodiment, the arc-shaped detection units 41a to 41f and 42a to 42a are respectively formed by the first and second ring-shaped radiation sensors 41s and 42s.
f detects γ-rays, and each logical product data processing device 14
Since it is detected that the detection is simultaneously performed with respect to the sets of the detection units having the same relative positions, in addition to the effect of the sixth embodiment, it is possible to reduce a detection error due to coincidence detection that occurs by accident,
Reliability can be improved.

(Eighth Embodiment) FIG. 10 shows an eighth embodiment of the present invention.
A directional γ-ray detection device according to the embodiment will be described. This directional γ-ray detector has 36 detectors arranged in a plane of 6 × 6 and is arranged in parallel and opposed to each other in a parallel plate shape, and the incident γ-rays are individually detected by the respective detectors. First and second radiation sensors 51 and 52 for detecting,
And second position identification devices 53 ₁ and 53 ₂ individually connected to the first and second radiation sensors 51 and 52, and a data processing device 5 connected to both position identification devices 53 ₁ and 53 ₂
4 is provided.

[0118] Here, the first position identification unit 53 ₁ has a function of converting the detection signal of the detection unit to the position coordinates, of the detector of the first radiation sensor 51, detects the γ ray The detected position coordinate signal (x, y) of the detection unit is
4

[0119] Similarly, the second position identification device 53 ₂ has a function of converting the detection signal of the detection unit to the position coordinates, of the detection unit of the second radiation sensor 52, detects the γ ray The detected position coordinate signal (X, Y) of the detection unit is
4 In addition, instead of the position coordinate signal,
Identification information such as a serial number may be used.

[0120] The data processing apparatus 54 when receiving the position coordinate signals simultaneously from the first and second position identification device ₅₃ 1, 53 _2, a detection unit in the first radiation sensor 51 second radiation sensor 52 Of the respective detection units that have simultaneously detected the γ-rays, and the detection unit is a predetermined set along the incident path of the γ-rays incident from a predetermined incident direction. It has a function of determining whether or not the detection result is valid and validating the detection result of a predetermined group.

In the data processing device 14, the distance from the focal point f and the positional relationship between the first and second radiation sensors 51 and 52 are set in advance. For example, as shown in FIG. When there is a geometric relationship that a straight line extending from the position passes through each detection unit at each position coordinate, it can be determined that the line is a predetermined set.

Next, the operation of such a directional gamma ray detecting device will be described. The γ-ray emitted from near the focal point f is the first
And the forward scattered component is incident on each of the detection units of the second radiation sensor 52 with a high probability. Specifically, the γ-ray arriving from the focal point f is converted into a first and a second radiation sensor 51 on a straight line extending from the focal point f.
Simultaneously enter the predetermined set of detection units at 52.

On the other hand, γ radiated from other than near the focal point f
Although the line is simultaneously incident on each set of detection units of the first and second radiation sensors 51 and 52, it is incident on each detection unit of a combination different from the predetermined set corresponding to the focal point f.

Here, in the first radiation sensor 51, each detection section outputs a γ-ray detection signal to the first position identification device 5.
3 gives to _1. The first position identification device 53 ₁ converts the position coordinate signal of the detector the detection signals respectively corresponding, gives the position coordinate signal to the data processing unit 54. Similarly given a second radiation sensor 52 detects signals of the respective detector is γ rays ₂ second position identification device 53, a second position identification device 5
3 ₂ gives the position coordinate signal corresponding to the detection unit to the data processing unit 54.

[0125] The data processing apparatus 54 when receiving the position coordinate signals simultaneously from the first and second position identification device ₅₃ 1, 53 _2, a detection unit in the first radiation sensor 51 second radiation sensor 52 It is recognized that each of the detection units has detected γ-rays at the same time.

Then, the data processing device 54 determines whether or not each of the sets of the detection units that have been detected at the same time is a predetermined set along the incident path of the γ-ray incident from a predetermined incident direction. , The detection result of the predetermined set is validated and stored as a logical sum. Thereby, relatively high sensitivity to γ-rays from near the focal point f can be realized.

As described above, according to the present embodiment, the first
In the second and third radiation sensors 51 and 52, a plurality of detection units arranged in a plane form individually detect γ-rays, and the first and second position identification devices 53 ₁ and 53 _{2 use} the respective radiation sensors. 5
The position coordinate signal of the detection unit that has detected γ-rays within the first and second detectors 52 is supplied to the data processor 54, and when the data processor 54 receives the position coordinate signal from each of the position identification devices 53 ₁ and 53 ₂ simultaneously, Is determined at the same time for each set of detectors, whether or not the set is a predetermined set along the incident path of the γ-ray incident from a predetermined incident direction, and the detection result by the predetermined set is validated. , Even in a state surrounded by a γ-ray source,
Γ-rays incident from a γ-ray source located at the apex of a cone including each set of detection units can be selectively detected, thereby realizing high directivity. In addition, relatively high sensitivity can be realized in proportion to the number of sets of the predetermined detection units.

In addition, as described above, sharp directivity can be easily realized in principle, can be realized at low cost, and can be easily installed at any place.

Note that each of the radiation sensors 51,
Although the detector 52 has 36 detectors of 6 × 6, it is needless to say that the detector 52 may be formed of any other detector having an arbitrary arrangement and number of columns.

(Ninth Embodiment) FIG. 11 shows a ninth embodiment of the present invention.
It is a schematic diagram which shows the structure of the directional gamma ray detection system which concerns on embodiment. This directional γ-ray detection system includes a directional γ-ray detection device 10j of any one of the sixth to eighth embodiments, and a camera 31, an imaging device 32, and a display device similar to those of the fourth embodiment. 33 is applied. Note that the field of view of the camera 31 includes the focal point f.

With the above configuration, similarly to the fourth embodiment, the camera 31 captures a visible image in the direction of arrival of γ-rays, and the imaging device 32 transmits the first radiation sensor (41, 41).
Since the indication of the arrival direction of the γ-rays obtained based on the directivity of 41s or 51) and the visible image taken by the camera 31 are combined, the corresponding directivity γ of the sixth to eighth embodiments is used. In addition to the effects of the line detector, a visible image of the γ-ray source can be visually recognized. Further, if desired, a visible image to which γ-ray intensity information or the like is added can be visually recognized.

Further, in this embodiment, since it is assumed that the focal position of the γ-ray is included in the focal length plane of the image, if necessary, the vicinity of the focal point f is determined based on the focal length information which can be set in advance. The imaging device 32 may be provided with a function of calculating the surface dose rate, the ambient air dose rate, and the like, and combine the calculation result with a visible image as appropriate.

(Tenth Embodiment) FIG. 12 is a schematic diagram showing a configuration of a directional γ-ray detection system according to a tenth embodiment of the present invention. This directional γ-ray detection system is a modification of the ninth embodiment.
Is provided in the vicinity of the radiation sensor (41, 41s or 51), and a remote non-contact type distance meter 55 that measures the focal length of a visible image and gives the measurement result to the imaging device 32a.

Here, the imaging device 32a has a dose rate calculation function for calculating the surface dose rate at the focal position of the visible image based on the focal length measured by the range finder, in addition to the above-described functions such as image synthesis. And a result sending function to be given to the image synthesizing function so as to display the calculation result by the dose rate calculating function.

Next, the operation of such a directional γ-ray detection system will be described. Now, as shown in FIG. 12, the distance from the directional γ-ray detector 10j to the focal point f and the camera 3
It is assumed that the distance from 1 to the focal plane fg of the visible image is different. The distance meter 55 measures the focal length of the visible image, and provides the measurement result to the imaging device 32a. As described above, the imaging device 32a calculates the dose rate at the focal point f obtained from the directional γ-ray detection device 10j based on the focal length f of the visible image obtained from the rangefinder 55, based on the focal plane f of the visible image.
Convert to surface dose rate in g.

The imaging device 32a combines the conversion result with a visible image, and causes the display device 33 to display the combined result.

As described above, according to the present embodiment, the range finder 55 measures the focal length of the visible image, and
2a calculates the surface dose rate of the focal plane fg of the visible image based on the focal length measured by the distance meter 55, and gives the calculated result to the image synthesizing function so as to display the calculation result. The focus f of 10j is not on the surface of the object,
That is, even when the focus is different from the focus of the visible image, the detection result of γ-rays by the directional γ-ray detection device 10j can be converted into the surface dose rate of the photographed object, and the conversion result can be obtained in the ninth embodiment. Can be added to the combined visible image obtained by

In this embodiment, the case where the range finder 55 is added to obtain the focal length of the visible image has been described. However, the present invention is not limited to this, and the case where the camera 31 has a function of measuring the focal length of the visible image is provided. In this case, even if the distance meter 55 is omitted and the measurement function of the camera 31 is used, the present embodiment can be implemented in the same manner and the same effect can be obtained.

(Eleventh Embodiment) FIG. 13 is a schematic diagram showing the configuration of a directional γ-ray detection system according to an eleventh embodiment of the present invention. This directional γ-ray detection system is a modification of the fifth embodiment. In addition to the configuration of the fifth embodiment, the directional γ-ray detection devices 10 i Arrangement direction (Estimated angle θ1,
θ2) is changed individually to scan the position of the focal point f, and the output of the two directional γ-ray detectors 10i at each focal point f is added and counted to create measurement data. Measuring unit 62, a recording unit 63 for recording the measurement data obtained from the measurement unit 62 and the focal position obtained from the scanning unit 61 in synchronization and forming a set, and each measurement data and focus recorded on the recording unit 63. A map creation unit 64 for creating a one- to three-dimensional map of each measurement data based on the position.

Next, the operation of such a directional γ-ray detection system will be described. Now, two directional γ-ray detectors 1
Under the control of the arrangement direction changing unit by the scanning unit 61, 0i is arranged with the expected angles θ1 and θ2 toward the focal point f. Each directional γ-ray detection device 10i detects a γ-ray arriving from the position of the focal point f, and sends a detection signal to the measurement unit 62.

The measuring section 62 is provided for each directional γ-ray detecting device 10.
i, respectively, adds and counts the detection signals sent from i to generate measurement data.
Output to

On the other hand, the scanning section 61 sends the current focus f position to the recording section 63 in synchronization with the output of the measuring section 62. The recording unit 63 records the measurement data obtained from the measurement unit 62 and the focal point f position obtained from the scanning unit 61 in synchronization with each other.

As described above, the measurement of the γ-ray coming from the focal point f at a certain focal position is completed. Next, the scanning unit 61 arranges each directional γ-ray detection device 10i toward another focal point f ′ under the control of the arrangement direction changing unit. The γ-ray coming from the focal point f ′ is detected by each directional γ-ray detecting device 10i, and the detection result is recorded in the recording unit 63 as a set of the measurement data and the focal position as described above.

Similarly, the arrangement direction of the directional γ-ray detector 10i is arbitrarily changed, and the realized focal point f is scanned in a one-dimensional direction, a two-dimensional plane, or a three-dimensional space. The position and its measurement data are recorded.

After the measurement is completed, the map creating section 64 creates a map in one-dimensional direction, two-dimensional plane, or three-dimensional space of each measurement data based on each measurement data and the focal position recorded in the recording section 63. Then, the map is output to a display device or the like (not shown). Note that the map creation unit 64 may create and update a map sequentially during measurement and output the map.

As described above, according to the present embodiment, the scanning unit 61 controls the arrangement directions of the directional γ-ray detectors 10i (the estimated angles θ1, θ2) under the control of the arrangement direction changing unit.
Scan the focal point f position realized by individually changing 2),
The measurement unit 62 adds and counts the outputs of the two directional γ-ray detectors 62 at each focal position to create measurement data, and the recording unit 63 scans the measurement data obtained from the measurement unit 62 with the scanning data. The focal point f position obtained from the unit 61 is recorded in a group in synchronization with each other, and the map creating unit 64 uses the measured data recorded in the recording unit 63 and the focal point position to record the first to third dimensions of each measured data. Is created, in addition to the effect of the fifth embodiment, the γ-ray intensity distribution in the space can be measured, and the measured data can be shown in a map form.

(Twelfth Embodiment) FIG. 14 is a schematic diagram showing the configuration of a directional γ-ray detector according to a twelfth embodiment of the present invention. This directional γ-ray detection device is a modification of the eleventh embodiment, in which each radiation sensor is replaced with each of the ring-shaped radiation sensors 41 and 42 of the sixth (or seventh) embodiment.
(Or 41s, 42s), and the scanning unit 61 is deformed so that the ring-shaped radiation sensors 41, 42 can be scanned, and the measuring unit 62 is replaced with the electronic circuits 13 ₁ , 13 ₂ and the logical product type data processing device. 14 is adopted. Although not shown, each radiation sensor 41s, 4 in ()
When 2s is used, it goes without saying that the measurement unit 62 has the configuration shown in FIG. 9B.

Here, the scanning unit is a ring-shaped radiation sensor 41, 42 (or 41) shown in FIG. 8 (or FIG. 9).
By decentering the relative distance and the ring center position in (s, 42s), the position of the focal point f can be changed to scan in a one-dimensional direction, a two-dimensional plane, or a three-dimensional space. For example, by changing the relative distance between the ring-shaped radiation sensors 41 and 42, the focal point can be moved in the front and rear one-dimensional directions, and by decentering the ring center position, the focal point can be moved in the two-dimensional direction. The focal point f can be moved by driving one or both of the radiation sensors 41 and 42. However, driving the small-diameter first radiation sensor 41 can simplify the configuration and perform position control. It is preferable from the viewpoint of facilitation of the process.

With the above structure, the scanning unit 61
Are the first and second radiation sensors 41, 42 (or 41).
s, 42s), any one of the radiation sensors 41, 42 (or 41s, 42s) is moved to change the relative distance between the first and second radiation sensors 41, 42.
(Or 41s, 42s) so that the center axes of the respective rings are eccentric.
By moving either or both of 2s), the focal position realized by changing the relative arrangement of each radiation sensor 41, 42 (or 41s, 42s) is scanned, and the logical product type data processing device 14 The detection result of each radiation sensor 41, 42 (or 41s, 42s) at each focal position is subjected to coincidence processing to generate measurement data, and the recording unit 63 stores the measurement data obtained from the logical product data processing device 14. And the focal position obtained from the scanning unit 61 are recorded as a set in synchronization with each other, and the map creating unit 62 uses the measured data and the focal position recorded in the recording unit 63 to record each of the measured data 1-3. Since the dimensional map is created, in addition to the effects of the sixth or seventh embodiment, the γ-ray intensity distribution in the space can be measured similarly to the eleventh embodiment, and the measurement results are mapped and shown. It can be.

(Thirteenth Embodiment) FIG. 15 is a schematic diagram showing the configuration of a directional γ-ray detector according to a thirteenth embodiment of the present invention. This directional γ-ray detection device is a modification of the twelfth embodiment, and includes ring-shaped radiation sensors 41,
Instead of 42 (or 41 s, 42 s), parallel plate-shaped radiation sensors 51 and 52 of the eighth embodiment are provided.

With the above-described configuration, similarly to the twelfth embodiment, the focal position f can be changed by decentering the relative distance between the radiation sensors 51 and 52 and the center position of the radiation sensors 51 and 52. , The γ-ray intensity distribution in the space can be measured, and a one- to three-dimensional map of each measurement data can be created.

In this embodiment, each radiation sensor 5
If 1,52 has necessary and sufficient area and positional resolution,
Without changing the mutual position of each radiation sensor 51, 52,
The effective focus position may be changed by changing only the combination of the detection units for simultaneous counting. Accordingly, the γ-ray intensity distribution in the space can be measured without driving the radiation sensors 51 and 52, and a one- to three-dimensional map of each measurement data can be created. In addition, the radiation sensor 51,
A drive mechanism for controlling the position of 52 can be omitted, and the configuration can be simplified.

In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0154]

As described above, according to the present invention, γ
Provided is a directional γ-ray detection device capable of selectively detecting γ-rays arriving from an object even in a state surrounded by a radiation source, thereby realizing high directivity, and a detection system using the same. it can.

In addition, sharp directivity can be easily realized in principle, at low cost, and can be easily installed at any place.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a directional γ-ray detection device according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing directivity of each radiation sensor in the embodiment.

FIG. 3 is a schematic diagram illustrating a configuration of a directional γ-ray detection device according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram showing a configuration of a directional γ-ray detection device according to a third embodiment of the present invention.

FIG. 5 is a schematic diagram showing a cross-sectional configuration of the radiation sensor according to the embodiment.

FIG. 6 is a schematic diagram illustrating a configuration of a directional γ-ray detection system according to a fourth embodiment of the present invention.

FIG. 7 is a schematic diagram showing a configuration of a directional γ-ray detection system according to a fifth embodiment of the present invention.

FIG. 8 is a schematic diagram illustrating a configuration of a directional γ-ray detection device according to a sixth embodiment of the present invention.

FIG. 9 is a schematic diagram illustrating a configuration of a directional γ-ray detection device according to a seventh embodiment of the present invention.

FIG. 10 is a schematic diagram illustrating a configuration of a directional γ-ray detection device according to an eighth embodiment of the present invention.

FIG. 11 is a schematic diagram showing a configuration of a directional γ-ray detection system according to a ninth embodiment of the present invention.

FIG. 12 is a schematic diagram showing a configuration of a directional γ-ray detection system according to a tenth embodiment of the present invention.

FIG. 13 is a schematic diagram showing a configuration of a directional γ-ray detection system according to an eleventh embodiment of the present invention.

FIG. 14 is a schematic diagram showing a configuration of a directional γ-ray detection device according to a twelfth embodiment of the present invention.

FIG. 15 is a schematic diagram showing a configuration of a directional γ-ray detection device according to a thirteenth embodiment of the present invention.

FIG. 16 is a schematic diagram showing a configuration of a detector of a conventional directional γ-ray detection device.

FIG. 17 is a schematic diagram showing a configuration of a detector of a conventional directional γ-ray detection device.

FIG. 18 is a schematic diagram showing a configuration of a detector of a conventional directional γ-ray detector.

[Explanation of symbols]

10, 10a, 10b, 10i, 10j ... directional γ ray detector 11,41,41S, 51 ... first radiation sensor 12,12a, 42,42s, 52 ... second radiation sensor 13 _1, 13 ₂ ... electronic circuit 14 ... logical data processing device 21, 22 ... scintillator 23 _1, 23 2 _... wavelength shifting fiber 24 ... reflector 25 ... case 26 _1, 26 2 _... optical connector 27 _1, 27 2 _... specular reflector 28 ... shielding layer 29 _1, 29 _{2 ... optical fiber 31 ... camera 32, 32a ... imaging apparatus 33 ... display device} 41a to 41f, 42a-42f ... detection unit 53 _1, 53 _{2 ... position identification device} 54 ... data processing unit 55 ... Rangefinder 61 Scanning unit 62 Measurement unit f Focus fg Focus plane θ1, θ2 Estimated angle

Claims (13)

[Claims] 1. A first radiation sensor having directivity for detecting a γ-ray incident along a predetermined incident direction with higher sensitivity than a γ-ray incident from another direction, and a rear of the first radiation sensor. A second radiation sensor that is disposed at the first radiation sensor and detects a forward scattered component of γ-rays that is incident on the first radiation sensor and is Compton-scattered;
A directional γ-ray detection device, comprising: a simultaneity detection unit for detecting that the detections by the second radiation sensor are simultaneous. 2. The directional γ-ray detection device according to claim 1, wherein the second radiation sensor is configured such that γ-rays incident from a direction in which the first radiation sensor is arranged are higher than γ-rays incident from another direction. A directional γ-ray detection device, characterized in that the directional γ-ray detection device has a directivity for detecting the γ-rays with high sensitivity. 3. The directivity γ according to claim 1 or 2.
In the line detection device, any one or both of the radiation sensors is a scintillator that generates light due to the incidence of γ-rays, and condenses the light in the scintillator to give to a subsequent-stage simultaneousness detection unit. A directional γ-ray detecting device, comprising: 4. The directional γ-ray detecting device according to claim 1, wherein the directional γ-ray detecting device is arranged near the first radiation sensor, and captures a visible image in a direction of arrival of the γ-ray. And an image synthesizing unit for synthesizing an indication of an arrival direction of the γ-ray obtained based on the directivity of the first radiation sensor and a visible image captured by the imaging unit. Characteristic directional γ-ray detector. 5. A directional γ-ray detection system using the directional γ-ray detection device according to claim 1, wherein a plurality of the directional γ-ray detection devices are arranged. A simultaneous detection and addition unit that adds together the synchronization detection signals output from the respective directional γ-ray detection devices and outputs an addition result; and individually changes the arrangement direction of the directional γ-ray detection devices. Directional γ-ray detection system, comprising: 6. It has a ring shape of a radius different from each other,
First and second radiation sensors for detecting incident γ-rays, which are arranged so as to be spaced apart from each other so that each ring is parallel, and that detection by the first and second radiation sensors is simultaneous. A directional γ-ray detection device comprising: a simultaneity detection means for detecting. 7. The directional γ-ray detection device according to claim 6, wherein the first and second radiation sensors have a same number of arc-shaped detectors each having the same number as each other, and the synchronization detection. The directional γ-ray detection device is characterized in that the means detects that the detection is simultaneously performed with respect to a set of detection units having the same relative position. 8. A first and a second radiation sensor having a plurality of detectors arranged in a plane and opposed to each other in a parallel plate shape, and detecting incident γ-rays individually by the respective detectors. When the detection unit in the first radiation sensor and the detection unit in the second radiation sensor respectively detect γ-rays, a predetermined incident direction is set for each set of detection units that have been detected simultaneously. Directivity gamma ray detection, comprising: a combination judging means for judging whether or not the combination is a predetermined group along an incident path of gamma rays incident from the camera, and validating a detection result by the predetermined group. apparatus. 9. The directional γ-ray detecting device according to claim 6, wherein the directional γ-ray detecting device is arranged near the first radiation sensor, and captures a visible image in a γ-ray arrival direction. And an image synthesizing unit for synthesizing an indication of an arrival direction of the γ-ray obtained based on the directivity of the first radiation sensor and a visible image captured by the imaging unit. Characteristic directional γ-ray detector. 10. The directional γ-ray detecting device according to claim 9, wherein the distance measuring unit is arranged near the first radiation sensor and measures a focal length of the visible image. Based on the measured focal length, a dose rate calculation unit that calculates a surface dose rate at the focal position of the visible image, and a calculation result that is sent to the image synthesis unit so that the calculation result by the dose rate calculation unit is displayed. A directional γ-ray detection device comprising: a transmission unit. 11. The directional γ-ray detection system according to claim 5, wherein the position of the directional γ-ray detection device is controlled by controlling the arrangement direction changing means to individually change the arrangement direction of each directional γ-ray detection device. Scanning measurement means for scanning and recording measurement data of γ-rays at each focal position, and map creation for creating a map of each measurement result based on each measurement data and scanning content obtained by the scanning measurement means Means for detecting directional γ-rays. 12. The directional γ-ray detection device according to claim 6, wherein one of the radiations changes a relative distance between the first and second radiation sensors. A distance changing unit that moves the sensor; an eccentricity control unit that moves any one of the radiation sensors so as to eccentric the center axes of the rings of the first and second radiation sensors; By the control of the eccentricity control means,
Scanning measuring means for scanning a focal position realized by changing the relative arrangement of each of the radiation sensors and recording measurement data of γ-rays at each focal position; and each measurement data obtained by the scanning measuring means. And a map creating means for creating a map of each measurement result based on the scanning content. 13. The directional γ-ray detecting apparatus according to claim 8, wherein: a combination changing unit that changes a set of each detection unit of the first and second radiation sensors; A scanning measurement unit that scans a focal position realized by changing the set of each of the detection units, and records γ-ray measurement data at each focal position; and each measurement data and scan content obtained by the scanning measurement unit. A directional γ-ray detecting device, comprising: a map creating means for creating a map of each measurement result based on the.