JPH10232284A - Wavelength shift type radiation sensor and radiation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect particularly a β-ray by reducing thickness, size and position dependence and improving sensitivity. SOLUTION: A plurality of shift fibers 2 are disposed symmetrically along a peripheral edge of a scintillator 21. A photodetector 23 is mounted at a lengthwise direction end face of each fiber 22, and a reflector 24 for returning the light into the fiber is provided at the other end face. Reflectors 22a, 25 for reflecting lights toward inward of the scintillator are provided on an outer surface of the fiber 22 in non-contact with the paired scintillators and an outer surface of a peripheral edge of the scintillator provided with no fiber. Substance having smaller refractive index than that of the scintillator is disposed on a flat surface of the scintillator, and its outside of the surface is covered with a reflecting and shielding material for reflecting the light output from the scintillator inward the scintillator and shielding the light from an exterior.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation detection technique applied to, for example, surface contamination in nuclear facilities and the like, and in particular, to a wavelength shift type radiation sensor for detecting radiation by utilizing a light emission phenomenon and to use the sensor. Radiation detection device.

[0002]

2. Description of the Related Art Conventionally, various types of radiation detectors of this type are known, and a large area scintillator made of plastic is often used as a detector for .beta.-rays having a large range. .

FIGS. 36 to 40 show various conventional examples of such a large-area β-ray detection sensor, which are widely used for surface contamination inspection in nuclear facilities.

The radiation sensor shown in FIG. 36 is of a box shape, and one surface (the upper surface in the figure) of the light collecting box 1 is a light collecting surface and the other 5
The three inner surfaces are all reflective surfaces treated to reflect light. The upper lid portion of the light-collecting box 1 is made of a thin plastic scintillator 2, and the upper part of the plastic scintillator 2 (outside the inner surface of the light-collecting box) is capable of transmitting β-rays and reflects light inward. It is covered with a sheet (not shown) which can be used.

[0005] Then, the scintillator 2
The light generated inside is filled while being reflected inside the light collecting box 1, and is detected by the light detector 3 installed inside the light collecting box 1.

FIG. 37 shows a large-area β-ray detecting device constituted by a gas flow type sensor. This device is one of the common proportional counters that collects the ion pairs that beta rays create in the gas. In this case, the upper surface of the box-shaped container 4 is a light incident window 5 formed of a sheet capable of receiving β-rays and enclosing and holding gas, and the ionizing gas is slowly introduced into the container 4 through the gas pipe 6. It keeps flowing.

Further, what is shown in FIGS. 38 and 39 is as follows.
This is a radiation sensor used in a scintillation calorimeter. In the example of FIG. 38, the wavelength shift fiber 7 is spirally adhered to the flat portion of the flat plastic scintillator 2, and the transmission optical fiber 8 is connected to one longitudinal end face of the wavelength shift fiber 7. The signal is transmitted to a photodetector (not shown). That is, the scintillation light generated by the scintillator 2 encounters the wavelength shift fiber 7 and undergoes fluorescence conversion, and this fluorescence pulse is transmitted by the transparent transmission fiber 8.

Further, the sensor shown in FIG. 39 has a similar function, and a pair of L-shaped resin prism lights made of a pair of L-shaped resins each including a phosphor on the outer peripheral edge of a rectangular plate-shaped plastic scintillator 2. A guide (hereinafter, referred to as a wavelength shift bar) 9 is disposed, and a corner portion where each wavelength shift bar 9 meets is further connected to a photodetector 11 via a second wavelength shift bar 10. The first wavelength shift bar 9 in contact with the scintillator 2 is excited by the scintillation wavelength and emits fluorescence, while the second wavelength shift bar 10 is excited by the fluorescence emitted by the first wavelength shift bar 9, and It emits long wavelength light.

It is assumed that both the sensors shown in FIGS. 38 and 39 are used by alternately stacking the lead plate 12 and the like and the scintillator 2 in multiple layers as shown in FIG.

In these sensors, a cascade shower of electrons (β-rays) and γ-rays occurs as a result of the incidence of GeV-order charged particles, and the scintillator 2 has a multilayer structure.
This shower passes through the inside. Therefore, the scintillator 2 of each layer emits light by a large amount of electrons generated at one time, and it is practical enough even if the amount of condensed light is slightly low.

[0011]

By the way, in a surface contamination inspection of a nuclear facility or the like, a wide range of contamination is measured at a time, a large number of sensors are arranged so as to surround the object to be measured, or These sensors need to be moved by a drive mechanism. For this reason, it has become an important issue to make the sensor itself thinner and smaller and lighter.

The sensors shown in FIGS. 36 and 37 are currently in practical use, and the sensors shown in FIGS. 38 and 39 are used for detecting an electron beam, although their fields are different. In light of the above objects, problems to be solved at the time of application are described below.

In the sensor shown in FIG. 36, first, it is necessary to increase the area of the light receiving portion of the photodetector 3 in order to secure the amount of condensed light. Therefore, in order to obtain practical performance, it is necessary to use a photomultiplier tube having a diameter of about 2 inches. For this reason, the depth of the light-collecting box 1 is inevitably increased, so that the overall size is increased and the weight is increased. In addition, the use of a large photomultiplier tube increases the probability of receiving light, but there is a contradictory condition that dark current noise increases due to a large photocathode.

For this reason, it has been difficult to make the system thinner and smaller than it is now with this method. In addition, the detection sensitivity at a position distant from the sensing surface is low, and it has been difficult to realize uniform sensitivity.

The sensor of FIG. 37 may also be used in a surface contamination inspection device. This type of sensor has high sensitivity and can be made thin, but it is structurally fragile because it seals the gas with a thin film, and it is necessary to provide a gas pipe 6 for flowing gas and a gas cylinder (not shown). ,
A large installation space is required, a complicated structure is required for application to a moving part, and further, there is a major drawback that maintainability is poor.

FIGS. 38 and 39 show a scintillation calorimeter in a high energy physics experiment in a different field from the previous two examples. The previous contamination inspection device used to count each beta ray emitted from a weak radionuclide as a normal beta ray detector, but this calorimeter uses a cascade shower of electrons and gamma rays to penetrate, It is designed to check the transmission state, and at the same time, to detect a large number of electrons (β rays) generated in a burst. For this reason, the amount of light generated is orders of magnitude larger, and the positional dependence of the sensitivity on the detection surface and the omission of counting of one β-ray are not much of a problem. Considerations have been added.

In the sensor shown in FIG. 38, more than half of the generated light is captured inside the scintillator 2 because the outer surface of the scintillator 2 is in contact with the air layer. For this reason, the probability of photons encountering the wavelength-shifting fiber 7 spirally arranged on the surface of the scintillator 2 is very low because it is only equivalent to the contact area with respect to the area of the scintillator, and the light-collection efficiency is low.

In the sensor shown in FIG. 39, the scintillator 2
Since the light that has been captured inside and has reached the outer peripheral edge is subjected to fluorescence conversion by the wavelength shift bar 9, the efficiency up to this point is high, but the second wavelength shift bar 10 is further introduced to change the light transmission direction. Therefore, the fluorescence conversion efficiency and the transmission efficiency are squared. Because of this, the originally weak light is further reduced,
As a result, only a very small amount of light is obtained. Therefore, as shown in FIG. 40, the two wavelength shift bars 10 are actually used in a stacked system. However, in this case, since the arrangement of the two wavelength shift bars 10 is in a cross shape, there is a problem in multilayering. It is conceivable to use the second wavelength shift bar 10 as a fiber for practical use, but as a result, the amount of condensed light is further reduced.

As described above, when the conventional sensor is used as a normal β-ray detector, the amount of condensed light is insufficient.
The sensitivity required for an inspection device cannot be obtained. Further, the optical symmetry is not taken into consideration, so that the amount of condensed light is insufficient, and light cannot be detected depending on the light emission position. As described above, since uniform light-collecting efficiency cannot be achieved over the entire surface, there has been a problem that the position dependency of the β-ray detection sensitivity particularly increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made to reduce the thickness by applying a condensing technique based on fluorescence conversion.
A wavelength shift that can be miniaturized and achieves higher sensitivity than before by the layout design that takes into account optical symmetry, etc., and has a small position dependency, especially effective for practical use for β-ray detection A radiation sensor and a radiation detection device are provided.

[0021]

In order to achieve the above object, according to the first aspect of the present invention, a flat scintillator,
A wavelength-shifting radiation sensor having at least a portion thereof optically in close contact with a peripheral portion of the scintillator and having a wavelength-shifting fiber that absorbs scintillation light and emits light having a long wavelength; The scintillator is constituted by a plurality of symmetrically arranged along the peripheral portion, and a photodetector is attached to one end face in the length direction of each wavelength shift fiber and light is applied to the other end face in the wavelength shift fiber. A reflector is provided for returning the light to the scintillator, and the light is reflected toward the inside of the scintillator on the outer surface of the wavelength-shifting fiber that is not in contact with the scintillator and on the outer surface of the periphery of the scintillator where the wavelength-shifting fiber is not provided. A scintillator having a smaller refractive index than the scintillator on a flat surface of the scintillator. Deploying, further outside of its faces,
The light emitted from the scintillator is reflected to the inside of the scintillator and covered with a reflective / light-shielding material capable of blocking light from the outside. And a wavelength-shifting radiation sensor characterized by being able to transmit light.

In the present invention, more than half of the light generated in the scintillator is captured in the scintillator in the total reflection mode due to the difference in the refractive index between the scintillator and air.
Since the captured scintillation light propagates to the side surface, high-density scintillation light is obtained on the side surface. Two or more bundles of one or more wavelength-shifting fibers are arranged on a part of this side surface, and when scintillation light is applied thereto, as a result, fluorescence conversion occurs inside the wavelength-shifting fiber, and the fluorescence is The light is captured in the wavelength-shifted fiber in the total internal reflection mode and reaches the fiber end face.

By providing a reflector on the side of the scintillator where the wavelength shifting fiber is not mounted, the probability of reflecting light inside the scintillator and encountering the wavelength shifting fiber is increased. Further, the reflector attached to the end face of the wavelength shift fiber to which the photodetector is not connected has a function of reflecting light to one end connected to the photodetector to increase the amount of condensed light. The reflector attached to the portion of the wavelength shifting fiber that is not in contact with the scintillator reflects the scintillation light that has been transmitted through the wavelength shifting fiber without being absorbed and converted by the fluorescence again to the wavelength shifting fiber, thereby improving the fluorescence conversion efficiency. Has the function of enhancing.

The reflective / shielding material covering the surface of the scintillator blocks light entering from the outside and also serves as an entrance window for radiation. Further, it also prevents light radiated into the air without being totally reflected in the scintillator. Has a function of increasing the probability of encountering a wavelength-shifting fiber by being reflected to the scintillator side.

According to the second aspect of the present invention, at least a portion of the scintillator is optically in close contact with the periphery of the scintillator, and the scintillator absorbs scintillation light and emits light having a long wavelength. In the wavelength-shifting radiation sensor having a fiber, the wavelength-shifting fiber includes two or more wavelength-surrounding fibers and surrounds the entire periphery of the scintillator, and a photodetector is provided on one end surface in the longitudinal direction of each wavelength-shifting fiber. A reflector which is attached and provided on the other end face for returning light into the wavelength shift fiber, and which reflects light toward the inside of the scintillator on the outer surface of the wavelength shift fiber which is not in contact with the scintillator. While a body is provided, a substance having a smaller refractive index than that of the scintillator is disposed on a flat surface of the scintillator. And further on the outside of the plane, reflection and capable of blocking the light from the outside as well as reflecting light emitted from the scintillator to the internal side of the scintillators
A wavelength-shifting radiation sensor is provided, wherein a light-shielding material is covered, and the reflection / light-shielding material is capable of transmitting radiation to be measured on at least the radiation incident side of the scintillator.

In the present invention, for example, two or more wavelength shift fibers are used so as to surround the entire periphery of the side surface of the plate-shaped scintillator, and all or a part of each fiber is optically adhered and disposed. Then, a photodetector is attached to one end face of each wavelength shift fiber, and a reflector for returning light into the wavelength shift fiber is provided on the other end face, and the outside that is not in close contact with the scintillator side face of the wavelength shift fiber. Is provided with a reflector that reflects light toward the inside of the scintillator, and a substance having a smaller refractive index than the scintillator is provided on the upper and lower surfaces (wide surfaces) of the scintillator. Further, outside the light, the light emitted from the scintillator is reflected toward the scintillator, and the light is covered with a reflective / light-shielding material capable of blocking light from the outside.

The present invention uses two sets of wavelength-shifting fibers bundled one by one or a plurality of bundles.
Unlike the first aspect, the two sets of wavelength-shifting fibers are in contact with all side surfaces of the flat scintillator, and there is no side surface that is not wavelength-shifted. The function and function are the same as in claim 1.

According to the third aspect of the present invention, at least a part of the flat scintillator is optically connected to the peripheral portion of the scintillator, and the scintillator absorbs the scintillation light and emits light having a long wavelength. A wavelength-shifting radiation sensor having a fiber, wherein the wavelength-shifting fiber is a single fiber, thereby surrounding the entire periphery of the scintillator, and photodetectors are mounted on both end surfaces in the longitudinal direction of the wavelength-shifting fiber. And, on the outer surface of the wavelength-shifted fiber with respect to the non-contact of the scintillator, a reflector that reflects light toward the inside of the scintillator is provided, while on the flat surface of the scintillator, the refractive index is higher than that of the scintillator. Deploy a small substance, and further, outside the surface, the light emitted from the scintillator is inside the scintillator. A wavelength-shifting material, which is capable of transmitting a radiation to be measured on at least the radiation incident side of the scintillator. Type radiation sensor is provided.

In the present invention, all or a part of a set of one or more wavelength-shifting fibers is provided in optically close contact with the entire surface of the flat scintillator so as to surround the entire periphery, and both ends of the wavelength-shifting fiber are provided. A photodetector is mounted on the surface. A reflector that reflects light toward the inside of the scintillator is provided on the outside of the wavelength-shifting fiber that is not in close contact with the side of the scintillator, and a material whose refractive index is smaller than that of the scintillator is provided on the upper and lower surfaces (wide surfaces) of the scintillator. Is provided, and the outside thereof is covered with a reflection / light shielding material capable of reflecting light emitted from the scintillator to the scintillator side and shielding light from the outside.

Therefore, the present invention uses a set of one or a plurality of bundled wavelength-shifted fibers, and has a structure in contact with the entire periphery of the flat scintillator. For this reason, the photodetectors are mounted on both ends of a set of wavelength-shifting fibers, respectively, and the reflection treatment at one end as in claims 1 and 2 is unnecessary. Other functions and functions are as defined in claim 1.

According to the fourth aspect of the present invention, at least a part of the flat scintillator is optically connected to the peripheral portion of the scintillator, and the scintillator absorbs the scintillation light and emits light having a long wavelength. In a wavelength-shifting radiation sensor having fibers, the wavelength-shifting fibers are arranged in two opposing portions of the peripheral edge of the scintillator, and photodetectors are attached to both end surfaces in the longitudinal direction of each wavelength-shifting fiber. And, the outer surface of the scintillator non-contact with the wavelength-shifting fiber, and the outer surface of the peripheral edge of the scintillator where the wavelength-shifting fiber is not provided, while providing a reflector that reflects light toward the inside of the scintillator, On the flat surface of the scintillator,
A substance having a refractive index smaller than that of the scintillator is provided, and furthermore, a reflection / light shielding that reflects light emitted from the scintillator to the inside of the scintillator and shields light from outside, outside the surface thereof. A wavelength-shifting radiation sensor is provided, wherein the reflection / shielding material is capable of transmitting radiation to be measured on at least the radiation incident side of the scintillator.

That is, two or more wavelength-shifting fibers are used on a part of the side surface of the flat scintillator, and all or a part of each of the fibers is disposed in close contact with each other, and light is detected on both end surfaces of each wavelength-shifting fiber. A reflector that reflects light toward the inside of the scintillator is provided on the outside of the wavelength shift fiber that is not in close contact with the side of the scintillator. In addition, a material whose refractive index is smaller than that of the scintillator is provided on the upper and lower surfaces (wide surfaces) of the scintillator, and the light outside the scintillator is reflected to the scintillator side, and the outside light is blocked. Cover with a reflective / light-shielding material that can be used.

According to the present invention, one or a plurality of
A set of wavelength-shifting fibers is used, and the wavelength-shifting fibers are arranged for the scintillator in the same manner as in claim 1, but two photodetectors are provided at each end of the two sets of wavelength-shifting fibers, for a total of four photodetectors. Attach and use. Instead of performing a reflection function at one end of the fiber, the light is directly detected. Claim 1 for other functions and functions
According to.

According to a fifth aspect of the present invention, there is provided a scintillator having a plate-like shape and a wavelength shifter which is at least partially connected to the periphery of the scintillator in an optically intimate manner, absorbs scintillation light and emits light having a long wavelength. In the wavelength-shifting radiation sensor having a fiber, the scintillator is formed in a polygonal shape, the wavelength-shifting fibers are arranged on each edge thereof, and a photodetector is mounted on one end surface of each wavelength-shifting fiber in the longitudinal direction. At the same time, a reflector for returning light into the wavelength shift fiber is provided on the other end surface, and the light is reflected toward the inside of the scintillator on the non-contact outer surface of each wavelength shift fiber with respect to the scintillator. While a reflector is provided, a substance whose refractive index is smaller than that of the scintillator is placed on a flat surface of the scintillator. And a reflective / light-shielding material capable of reflecting light emitted from the scintillator to the inside of the scintillator and shielding light from the outside, and covering the outside of the surface with the scintillator. A wavelength shift type radiation sensor, characterized in that the radiation to be measured can be transmitted at least on the radiation incident side.

That is, all or a portion of each of the number of wavelength shift fibers corresponding to an integral multiple of the number of sides is optically closely attached to a part of the side surface of the flat scintillator, and one end face of each wavelength shift fiber is provided. And a reflector for returning light into the wavelength shift fiber is provided on the other end surface. A reflector that reflects light inward of the scintillator is provided on the outside of the wavelength-shifting fiber that is not in close contact with the side surface of the scintillator, and the upper and lower surfaces (wide surfaces) of the scintillator have a smaller refractive index than the scintillator. Deploy the substance. Further, the outside thereof is covered with a reflective / light-shielding material that can reflect light emitted from the scintillator to the scintillator side and shield external light.

According to the present invention, one or a plurality of
A set of wavelength-shifting fibers is used. Four sets of wavelength-shifting fibers and a photodetector are mounted on all sides of the flat scintillator, and a reflector is attached to one end of each of the wavelength-shifting fibers. The amount of light focused on the detector is increased. Other functions and functions are as defined in claim 1.

According to a sixth aspect of the present invention, in the wavelength shift type radiation sensor according to any one of the first to fifth aspects, the wavelength shift fiber and the photodetector are a transparent optical fiber, a light guide, or a light pipe. Wherein the optical detector is connected independently by means for optical transmission, and the photodetector has an independent configuration for individually receiving optical signals from the wavelength shifting fiber, or a common configuration for collectively receiving optical signals from the wavelength shift fiber. Type radiation sensor is provided.

That is, in the sensor described in any one of claims 1 to 5, a transparent optical fiber for light transmission, a light guide or a light pipe is interposed between the end of the wavelength shift fiber and the photodetector. A structure is added in which the optical signal from the shift fiber end is transmitted to individual independent or common photodetectors.

In the first embodiment, the photodetector is directly attached to the end of the wavelength shift fiber, but in the present invention, the optical transmission path is interposed between the optical detector and the optical transmission line as described above. Other functions and functions are according to claims 1 to 5.

According to a seventh aspect of the present invention, in the wavelength shift type radiation sensor according to the first, fourth or fifth aspect, a prism or a cylinder having a fluorescence function equivalent to that of the wavelength shift fiber is used instead of the wavelength shift fiber. A wavelength shift type radiation sensor comprising a wavelength shift bar made of a transparent resin or glass is provided.

That is, in the sensor described in claims 1, 4, and 5, a prism or a cylinder containing a phosphor having an action equivalent to that of the phosphor contained in the wavelength shift fiber is used instead of the wavelength shift fiber. A wavelength shift bar made of resin or glass is used.

In the present invention, the wavelength-shifted fiber has one or more cladding layers with respect to the core, but an uncladding fiber in which the cladding layer is replaced with surrounding air can be used. In addition, a wavelength shift bar formed by solidifying a phosphor (wavelength shifter) with resin or glass and processing it into a light guide or light pipe shape can be used as a substitute for a wavelength shift fiber.

According to an eighth aspect of the present invention, in the wavelength shift type radiation sensor according to the fifth aspect, a prismatic or cylindrical transparent resin or glass having a fluorescence function equivalent to that of the wavelength shift fiber is used instead of the wavelength shift fiber. A wavelength shift bar comprising: a wavelength shift bar comprising: a wavelength shift bar; and a configuration wherein light from two or more of the wavelength shift bars is combined and guided to a photodetector.

That is, in the sensor described in claim 5,
Instead of a wavelength-shifting fiber, use a wavelength-shifting bar made of resin or glass in the shape of a prism or a cylinder containing a phosphor having the same effect as the phosphor contained in the wavelength-shifting fiber. A light guide having a function of merging light from the shift bar and guiding the light to the photodetector is provided.

In the present invention, a fiber without a clad or a wavelength shift bar can be used instead of the wavelength shift fiber. Since the light guide can be cut or polished into any shape, a light guide that guides light from the two wavelength shift bars to a common photodetector is mounted. Alternatively, the end of the wavelength shift bar itself may be processed into the shape of a merging light guide.

According to a ninth aspect of the present invention, there is provided a radiation detecting apparatus using the wavelength shift type radiation sensor according to any one of the first to eighth aspects, wherein detection signals obtained from two systems of photodetectors are simultaneously output. Provided is a radiation detection apparatus characterized by including identification means for identifying a signal due to radiation when detected, and identifying other signals as signals such as noise of a photodetector.

That is, in the sensors described in claims 1 to 8, when detection signals obtained from two systems of photodetectors are detected simultaneously, the signals are regarded as signals due to radiation, and other signals are regarded as noises of the photodetectors. It also has a device that identifies it as such a signal.

The pulse signal due to the radiation observed by the photodetector is extremely weak, and in some cases, the noise signal of the photodetector is almost equal to the peak value. According to the present invention, all signals of single photons or more including noise are detected from the output signals of the two systems of detectors, and their coincidence is performed. The noise of the two photodetectors is uncorrelated and random, whereas the scintillation light is captured and diffused in the detector and reaches the two wavelength-shifted fibers almost simultaneously.
It will be detected simultaneously by two systems of photodetectors. For this reason, only the signal for which the synchronism is established can be determined as a signal due to the incidence of radiation, and the other signals can be determined as uncorrelated signals, that is, detector noise. When four photodetectors are used, any two, any three, and any four coincidence counts can be taken. It is used in combination with these coincidence circuits.

According to a tenth aspect of the present invention, there is provided a radiation detecting apparatus using the wavelength shift type radiation sensor according to any one of the first to eighth aspects, wherein a pulse peak value of an output signal of each photodetector is used as a threshold. A radiation detector comprising: a comparator for comparing a reference voltage value as a value; and an identifier for identifying a signal lower than the threshold value as noise and a signal exceeding the threshold value as a radiation detection signal. Provide equipment.

That is, in the sensors described in the first to eighth aspects, the pulse peak value of the output signal of each photodetector is compared with a reference voltage value serving as a threshold value, and a signal less than the threshold value is regarded as noise. , A signal exceeding the threshold is identified as a radiation detection signal.

In the present invention, the voltage of the output pulse signal of each photodetector is amplified to a required level, and then the reference voltage value is compared with a threshold value by a voltage comparison circuit or the like. Then, a pulse having a peak value equal to or higher than a certain level is calculated as a signal due to radiation, and if it is lower than the level, it is not counted as noise of the photodetector and the circuit system.

According to an eleventh aspect of the present invention, there is provided a wavelength shift type radiation sensor according to any one of the first to eighth aspects.
A radiation detection device, characterized in that it has means for identifying the type of incident radiation based on the length of its range by combining the presence or absence of independent signals output from these upper and lower sensors. provide.

That is, the sensor having the structure of claims 1 to 8 is configured to be in close contact with the upper and lower two layers, and has a device for identifying the type of incident radiation based on the combination of the presence and absence of upper and lower independent signals.

In the present invention, the radiation incident surface side (upper) is the first layer, and the lower layer is the second layer. The first layer has a thickness that is necessary when a short-range α-ray loses the total energy or an amount of energy close thereto. Therefore, when α rays enter, only the first layer emits light. Since β-rays have higher transmission power on average than α-rays, they penetrate the second layer while partially losing energy in the first layer, and lose all remaining energy in the second layer. The thickness of the second layer is determined so that the incident β-ray loses all energy in the first and second layers. Optically, the first layer and the second layer are separated from each other so as not to be affected by light emission from the other layers.

According to this configuration, when a signal is output only from the first layer, or when a large signal (having a value equal to or higher than the constant peak value) is detected with additional conditions, the signal by the α-ray is used. In other cases, it can be identified as a β-ray signal.

According to the twelfth aspect of the present invention,
The wavelength-shifting radiation sensor described in 4, 5, 6, 7, or 8 is adhered to upper and lower two layers, and a part of a plurality of wavelength-shifting fibers constituting each of these sensors is light from any of the upper and lower two-layer scintillators. It is configured to be in contact with each scintillator so that it can also receive and convert fluorescence, and based on the combination of the presence or absence of the detection signal from this common wavelength shift fiber and the independent signals output from the upper and lower sensors, the incident radiation A means for identifying the type of the radiation based on the length of the range.

That is, claims 1, 2, 4, 5, 6, 7, 8
The detector with the wavelength-shifting fiber is attached to the upper and lower two layers by the action described in (2), and a part of the plural sets of wavelength-shifting fibers used also receives light from any of the upper and lower two-layer scintillators. In addition, a device is disposed so as to be in contact with the scintillator so as to be able to perform fluorescence conversion, and has a device for identifying the type of incident radiation based on a combination of a detection signal from this common portion and the presence or absence of upper and lower independent signals.

In this case, the thicknesses of the first layer and the second layer can be determined in the same manner as in the eleventh aspect. In the eleventh aspect, independent light collecting and signal detecting systems are used in the first and second layers. Here, two sets of wavelength shift fibers or wavelength shift bars are provided for one layer of the scintillator. One is placed in contact with both scintillators in the two layers. When light is detected by this common wavelength-shifting fiber or wavelength-shifting bar, the synchronism with the detection signal of light from the remaining two layers of independent wavelength-shifting fiber or wavelength-shifting bar is checked. It is assumed that radiation was detected in the corresponding layer.

According to this configuration, when a signal is output only from the first layer, or when a large signal (having a certain peak value or more) is detected with additional conditions, a signal based on α rays is used. In other cases, it can be identified as a β-ray signal.

According to a thirteenth aspect of the present invention, there is provided a radiation detecting apparatus using the wavelength-shifting radiation sensor according to any one of the first to eighth aspects, wherein charged particles and Amplifying means for amplifying the output signal from the photodetector, and a comparing means for outputting the amplified signal only when the signal exceeds a certain threshold value. A radiation detection device comprising means for examining a count value of all radiation and a count value for each type of radiation by simultaneous discrimination between an output signal from the comparing means and a delayed output signal of the signal by a delay circuit. provide.

That is, in the sensor described in any one of claims 1 to 8, a layer which reacts with the charged particles and emits light is provided in close contact with the surface of the scintillator on the radiation incident surface side to amplify the output signal and provide a constant threshold value. And a function for checking the synchronism between the output of the voltage comparison circuit that outputs a signal while the delay time of the signal is output and the delay output of the delay circuit that delays the signal in time.

The invention according to claims 11 and 12 has a two-layer detector structure for discriminating .alpha. And .beta. Rays. However, the present invention has only one basic structure, and instead has a radiation incident surface of a scintillator. The side is coated with a scintillator that responds to α-rays.
The thickness to be applied is determined so that α-rays can sufficiently lose energy but β-rays can be transmitted. Light emitted from the applied scintillator or the scintillator serving as a matrix is converted into fluorescence by a wavelength shift fiber or a wavelength shift bar. For this reason, the signal of the two types of light emission is observed in a mixed state in the output of the photodetector. However, changing the type of the scintillator causes a difference in the light emission decay time.

When the output signal of the photodetector is amplified to a peak value within a certain range and converted into a logical output by a voltage comparator,
The pulse width can be longer or shorter according to the emission decay time. Although the pulse width depends to some extent on the peak value, if the difference in the decay time is large, the decay time is the main factor in determining the pulse width, so that the length of the decay time can be identified from the pulse width. The scintillator that emitted light is known by this identification, and it is known whether the light is emitted from the application surface or the mother scintillator, and α and β rays can be identified.

According to a fourteenth aspect of the present invention, in the wavelength-shifting radiation sensor according to any one of the first to eighth aspects, the wavelength-shifting fiber or the wavelength-shifting bar has a non-contact surface with the scintillator instead of a reflector. A wavelength-shifting radiation sensor characterized in that the peripheral portion of the flat scintillator is closely attached.

That is, a structure in which another scintillator is closely attached instead of the reflector provided on the surface not in contact with the scintillator in the first to eighth aspects is provided.

The present invention combines a plurality of scintillators,
The boundary and the end face are constituted by a wavelength shift fiber or a wavelength shift bar, and the detector has an enlarged sensing area.

According to a fifteenth aspect of the present invention, there is provided a radiation detecting apparatus using the wavelength shift type radiation detecting sensor according to the fourteenth aspect, wherein a detection signal obtained from two systems of photodetectors among a plurality of photodetection signals. A radiation detection apparatus characterized in that it is provided with an identification unit that considers a signal due to radiation when are simultaneously detected, and identifies other signals as signals such as noise of a photodetector.

That is, when the detection signals obtained from the two systems of photodetectors among the plurality of photodetection signals exceeding two at the same time are detected at the same time, it is regarded as a signal due to radiation, and other signals are detected. And a device for identifying as a signal such as noise of a photodetector.

The present invention regards the whole as one sensor despite being composed of a plurality of scintillators,
Logic that outputs a signal when radiation enters one of the scintillators is used.

According to a sixteenth aspect of the present invention, there is provided a radiation detecting apparatus using the wavelength shift type radiation detecting sensor according to the fourteenth aspect, wherein a detection signal obtained from two systems of photodetectors among a plurality of photodetection signals. Is detected as a signal due to radiation when they are detected simultaneously, and other signals are identified as signals such as noise of a photodetector, and the scintillator to which the radiation is incident is identified by a combination of the detected wavelength shift fibers. A radiation detection device having a function is provided.

In other words, in claim 14, when a detection signal obtained from two or more photodetectors among a plurality of photodetection signals exceeding two is detected simultaneously, it is regarded as a signal due to radiation, and other signals are detected. It has a function of identifying a signal as a signal such as a noise of a photodetector and a function of identifying a scintillator to which radiation has entered by a combination of wavelength-shifted fibers from which the signal is detected.

The present invention has a structure similar to that of the fifteenth embodiment, which is constituted by a plurality of scintillators, but does not consider the whole as one detector, and is independent for each scintillator when radiation is incident on each scintillator. Use logic that outputs signals.

[0073]

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

First Embodiment (FIGS. 1 to 6) FIG. 1 is a perspective view showing the entire configuration of a wavelength shift type radiation sensor according to the present embodiment, and FIG. 2 is a side view thereof.
3 to 6 are enlarged views showing a plurality of different configuration examples of the connection portion between the scintillator and the wavelength shift fiber.

As shown in FIGS. 1 and 2, this embodiment corresponds to a rectangular plate-shaped scintillator 21 and is optically connected to the peripheral edge of the scintillator 21 in close contact therewith. And a wavelength-shifting fiber 22 that absorbs scintillation light and emits light having a long wavelength. The wavelength-shifting fibers 22 are composed of a plurality of wavelength-shifting fibers 22 symmetrically arranged along the periphery of the scintillator 21, and a photodetector 23 is mounted on one end surface of each wavelength-shifting fiber 22 in the longitudinal direction. A reflector 2 on the other end face for returning light into the wavelength shift fiber 22.
4 are provided. A reflector 22 that reflects light toward the inside of the scintillator is provided on the outer surface of the wavelength shifting fiber 22 that is not in contact with the scintillator and on the outer surface of the periphery of the scintillator where the wavelength shifting fiber 22 is not provided.
a, 25 are provided. A substance having a smaller refractive index than that of the scintillator 21 is provided on the flat surface of the scintillator 21. Further, outside the surface, light emitted from the scintillator 21 is reflected inward of the scintillator and externally. A reflective / light-shielding material 26 capable of blocking light is covered. The reflection / shielding material 26 can transmit the radiation to be measured at least on the radiation incident side (upper surface side) of the scintillator 21.

In the first embodiment, more than half of the light generated in the scintillator 21 is
Due to the difference in the refractive index between the air and the air, the air is captured in the scintillator 21 in the total reflection mode. Since the captured scintillation light propagates to the side surface of the peripheral portion of the scintillator 21, high-density scintillation light is obtained on the side surface. Since one or a plurality of bundled wavelength-shifting fibers 22 are arranged on a part of this side surface, if scintillation light is irradiated here, fluorescence conversion occurs inside the wavelength-shifting fiber 22 as a result. The fluorescence is captured in the wavelength shift fiber 22 in the total reflection mode, and reaches the fiber end face.

In the side of the peripheral portion of the scintillator 21,
By providing the reflector 25 on the side where the wavelength shift fiber 22 is not attached, the scintillator 21 is provided.
Light is reflected inside and the probability of encountering the wavelength shifting fiber 22 can be increased.

The reflector 24 attached to the end face of the wavelength shift fiber 22 to which the photodetector 23 is not connected
By reflecting light to one end connected to the photodetector 23, the amount of light collected can be increased.

A reflector 22a attached to a portion of the wavelength shift fiber 22 that is not in contact with the scintillator 21
By reflecting the scintillation light transmitted through the wavelength shift fiber 22 without being absorbed and converted by the wavelength shift fiber 22 again to the wavelength shift fiber 22, the fluorescence conversion efficiency can be increased.

Further, the reflection / shielding material 26 covering the surface of the scintillator 21 blocks light entering from the outside and also serves as a radiation entrance window.
Even for light emitted into the air without being totally reflected inside,
By reflecting the light toward the scintillator 21 side, the probability of encountering the wavelength shift fiber 22 can be increased.

More specifically, in the sensor of this embodiment, the wavelength shift fiber 22 is disposed on two sides of the four sides of the rectangular flat scintillator 21 and the reflector is disposed on the remaining two sides.
Are mounted, and the boundary between the wavelength shift fiber 22 and the scintillator 21 is optically continuous. By setting the mounting position of the photodetector 23 connected to the end face of the wavelength shift fiber 22 at a diagonal position of the scintillator 21, optical symmetry is obtained, and sensitivity independent of the position can be realized.

As shown in FIG. 2, the entire sensor is covered with a reflective / light-shielding material 26. In addition to the role of shielding light from the outside, light emitted from the scintillator 21 is transmitted to the scintillator 21 side. Return, wavelength shift fiber 2
It also has the role of increasing the probability of encountering 2.

The reflection / shielding material 26 covering the whole is also a radiation entrance window on the upper side of the scintillator 21, so that
In the case where radiation having a low penetrating power is to be measured, it is necessary to form a film capable of transmitting the radiation. The reflectors 25 and 22a to be attached to the side surface of the outer peripheral edge of the scintillator 21 and the end face of the wavelength shift fiber 22 are not limited by such a film thickness or the like. Can be configured. Therefore, the reflectors 22a and 25 are provided at a plurality of positions of one sensor, but are not always made of the same material.

The absorption wavelength of the phosphor contained in the wavelength shift fiber 22 is adjusted to the emission wavelength of the scintillator 21 so that the most efficient fluorescence conversion is performed. Further, not only the wavelength, but also the geometrical conditions for causing the light collected on the side surface of the scintillator 21 to encounter the wavelength shift fiber 22 without being missed are required. This example is shown in FIGS.

As the cross-sectional shape of the wavelength-shifting fiber 22, a round shape, a square shape, or the like can be applied, and the diameter also varies, and different mounting methods are conceivable depending on the scintillator 21 to be used. Hereinafter, the relative relationship between the thickness (diameter or length of one side) of the wavelength shift fiber 22 and the thickness of the scintillator will be described irrespective of the corner or round shape.

FIG. 3 shows an example in which the wavelength shift fiber 22 is thinner than the thickness of the scintillator 21. In this case, the wavelength shift fiber 22 can be attached so as to cover the entire thickness, but it is also possible to collect light with a smaller number. In order to enhance the light collection efficiency, a plurality of wavelength shift fibers 22 are closely attached to each other or separated from each other, and are closely attached to the side surface of the scintillator 21. A reflector 24 is mounted on the rear side of the wavelength shift fiber 22 that is not in close contact with the scintillator 21, and the light that has escaped absorption is returned again to increase the fluorescence conversion efficiency. A space between the reflector 24 and the wavelength shift fiber 22 is filled with a transparent medium 27 having a similar refractive index to the constituent material of the wavelength shift fiber 22.

In the example of FIG. 4, the thickness of the scintillator 21 and the thickness of the wavelength shift fiber 22 are the same, and one wavelength shift fiber 22 is used. In the example of FIG. 5, a plurality of wavelength-shifting fibers 22 similar to the example of FIG. Also in these cases, the wavelength shift fiber 2
The reflector 22 is attached behind the 2.

FIG. 6 shows an example in which the thickness of the wavelength shift fiber 22 is larger than the thickness of the scintillator 21.
2 is configured to exceed the thickness of the scintillator 21. Of course, although not shown, one wavelength shift fiber 2
2 may be larger than the thickness of the scintillator 21.

Second Embodiment (FIG. 7) This embodiment corresponds to the second aspect of the present invention.

The present embodiment differs from the first embodiment in that the number of the wavelength shift fibers 22 is two or more, and they surround the entire periphery of the scintillator 21. A photodetector 23 is mounted on one end face in the length direction of each wavelength shift fiber 22, and a reflector 24 for returning light into the wavelength shift fiber 22 is provided on the other end face. A reflector 22 a that reflects light toward the inside of the scintillator 21 is provided on the outer surface of the wavelength shift fiber 22 that is not in contact with the scintillator. In this embodiment, since the wavelength shift fiber 22 is provided all around the scintillator, the scintillator 2
No reflecting surface is provided on the peripheral edge of No. 1. The other points are substantially the same as the first embodiment. In FIG. 7,
The illustration of the reflective / shielding material (26 in FIGS. 1 and 2) covering the flat surface of the scintillator 21 is omitted. This is the same in the following embodiments.

That is, in the second embodiment, two sets of wavelength shift fibers 22 bundled one by one or a plurality of sets are used so that the two sets of wavelength shift fibers 22 are in contact with the entire periphery of the scintillator 21. And there is no side that is not wavelength shifted. The two corners of the rectangular scintillator 21 are rounded with a curvature larger than the allowable bending radius of the wavelength shift fiber 22, and the wavelength shift fiber 22 is arranged.

According to such a second embodiment, the first
The same operation and effect as in the embodiment can be obtained. Although one set of the wavelength shift fiber 22 occupies two sides, by mounting the photodetector 23 on the diagonal position side, optical symmetry can be achieved, so that good sensitivity and That uniformity is obtained.

Third Embodiment (FIG. 8) This embodiment corresponds to the third aspect of the present invention.

This embodiment is different from the first and second embodiments in that only one wavelength shift fiber 22 is used to surround the entire periphery of the scintillator 21.
And that the photodetector 23 is attached to both end surfaces in the longitudinal direction of the wavelength shift fiber 22.

That is, in the present embodiment, the four corners of the rectangular scintillator 1 are formed into a circular shape having a curvature larger than the allowable bending radius of the wavelength shifting fiber 22, and one (or a set of a plurality of bundled) wavelength shifting is performed. The fiber 22 is arranged so as to make one round so as to be in contact with the entire circumference of the flat scintillator 21. For this reason, the photodetectors 23 are mounted on both ends of the pair of wavelength shift fibers 22, respectively, and the reflection treatment at one end as in the first and second embodiments is not required.

According to the present embodiment, the fluorescence generated in any part of the wavelength shift fiber 22 reaches both ends with a high probability and can be detected. In addition, there is a possibility that the light is propagated in the scintillator 21 and reaches everywhere in the wavelength shift fiber 22, thereby causing fluorescence conversion at a plurality of locations. Since they occur in a very short time, the total amount of light is increased, resulting in uniform and high sensitivity.

Fourth Embodiment (FIG. 9) This embodiment corresponds to the fourth aspect of the present invention.

This embodiment is different from the first to third embodiments in that two wavelength-shifting fibers 22 are disposed on two opposing sides of the periphery of a rectangular plate-shaped scintillator 21.
Photodetectors 23 are attached to both end surfaces in the length direction of each wavelength shift fiber 22, and the outer surface of the wavelength shift fiber 22 that is not in contact with the scintillator and the outer side of the peripheral edge of the scintillator 21 where the wavelength shift fiber 22 is not provided. The point is that reflectors 22a and 24 that reflect light toward the inside of the scintillator 21 are provided on the surface.

That is, the present embodiment uses one (or two sets of bundled plural) wavelength-shifting fibers 22. Similar to the first embodiment, the scintillator 21 is used.
The wavelength shift fibers 22 are arranged at two ends of each of the two sets of wavelength shift fibers 22, for a total of 4 wavelength shift fibers.
It is equipped with a plurality of photodetectors and detects light directly.
Other configurations and functions are substantially the same as those of the first embodiment.

According to the present embodiment, by mounting the photodetectors 23 at both ends of the wavelength shift fiber 22, the optical symmetry can be achieved while increasing the amount of light, so that the sensitivity and the uniformity can be further improved. Can be enhanced.

Fifth Embodiment (FIG. 10) This embodiment corresponds to the sixth aspect of the present invention.

This embodiment is different from the above embodiments in that
The scintillator has a polygonal shape, for example, a quadrangle, and the wavelength shift fibers 22 are arranged on each edge of the scintillator 21, and the photodetector 23 is attached to one end surface in the longitudinal direction of each wavelength shift fiber 22 and the other end surface. And a reflector 24 for returning light into the wavelength shift fiber 22 is provided.

In particular, in the present embodiment, each photodetector 23 is arranged at each corner position of the rectangular scintillator 21,
Optical symmetry can be achieved. Other configurations are substantially the same as those in the above embodiments.

According to the present embodiment, for example, by attaching the wavelength shift fibers 22 to all four sides of the rectangular scintillator 21, high sensitivity can be obtained as in the third embodiment, and each of the photodetectors 23 By providing a positional relationship of being arranged one at each corner of the scintillator 21, optical symmetry can be achieved, thereby improving good sensitivity and improving its uniformity.

Sixth Embodiment (FIGS. 11 to 13) This embodiment corresponds to the sixth aspect of the present invention. In the wavelength-shifting radiation sensor, the wavelength-shifting fiber 22 and the photodetector 23 are connected by means of light transmission including a transparent optical fiber, a light guide, or a light pipe. The photodetector 23 has an independent configuration for individually receiving optical signals from the wavelength shift fiber 22, or a common configuration for collectively receiving optical signals.

That is, in each of the above embodiments, the photodetector 2
3 is directly mounted on the end face of the wavelength shift fiber 22. However, when the thickness of the sensor and the installation space are limited, or when the photodetector 23 needs to be separated from the radiation sensitive part for some reason, the optical transmission between the photodetector 23 and the wavelength shift fiber 22 is performed. It is effective to intervene means that will be the road.

FIGS. 11 to 13 show the wavelength shift fiber 2.
Various types of connection structures of transmission optical fibers interposed between the optical fiber 2 and the photodetector 23 are shown.

In the example of FIG. 11, a wavelength shift fiber 22 and a transmission fiber 28 having the same specifications are connected, and they have the same refractive index and the same numerical aperture. The transmission optical fibers 28 having the same or larger core diameter
In this case, the connection with the lowest loss is possible. If the same specifications cannot be obtained, those having values in the vicinity can be used.

In the example of FIG. 12, when a plurality of wavelength shift fibers 22 are used, the transmission optical fiber 2 is used.
8 and 1: 1.

FIG. 13 shows an example in which a transmission optical fiber 28 having a diameter larger than the core diameter of the wavelength shift fiber 22 is used. A plurality of wavelength shift fibers 22 are collectively connected to the transmission optical fiber 28 having a larger diameter. It is.

FIGS. 14 to 16 show transmission optical fibers 28.
2 illustrates a connection configuration between the photodetector 23 and the power supply.

FIG. 14 shows a case where the end face of the wavelength shift fiber 22 and the light receiving section 29 of the photodetector 23 are connected one-to-one, and FIG. 15 shows a case where a plurality of transmission optical fibers 28 are grouped together. The case where it connects to the light receiving part 29 of two photodetectors 23 is shown.

In the case of a measurement for verifying the mutual time synchronization of detected signals, two or more photodetectors 23
However, when the signal and noise are distinguished by the amount of light, the output of the photodetector 23 can be processed by at least one system. It is effective to increase the amount of light.

FIG. 16 shows a case where a single photodetector 23 has a plurality of light receiving sections 29. That is, the photodetector 23 incorporates a plurality of photodetector elements therein (multi-anode photomultiplier tube), or the light receiving portion itself can detect the position (position-detection type photomultiplier tube). I do. In the case where such a photodetector is used, if a transmission optical fiber 28 is connected to each of the plurality of light receiving sections 29 of one photodetector 23, the function and the operation can be improved as shown in FIG.
However, the number of photodetectors 23 to be connected can be reduced, which is effective for downsizing the device.

Seventh Embodiment (FIGS. 17 and 18) This embodiment relates to the wavelength shift fiber 2 of each of the above embodiments .
In place of 2, a prism (FIG. 17) or a cylinder (FIG. 18) having a fluorescent function equivalent to that of the wavelength shift fiber 22
Wavelength shift bar 30 made of transparent resin or glass
This is for a wavelength-shifting radiation sensor provided with:

That is, the wavelength-shifting fiber 22 has one or more cladding layers for the core. The cladding layer is replaced with surrounding air without a cladding, and the phosphor (wavelength shifter) is made of resin or glass. The wavelength shift bar 30 fixed or solidified in the above and processed into a light guide or light pipe shape can be used as a substitute for the wavelength shift fiber 22.

Such a wavelength shift bar 30 is obtained by processing only a core, that is, a resin or a glass in which a phosphor serving as a wavelength shifter is processed into a column, a prism, or a plate shape. These are different from fibers, and can be any thickness, thickness,
Since it can be processed into a shape, a sufficient thickness required for fluorescence conversion can be easily formed. However, since there is no cladding, it is necessary to devise an air layer around the area. In addition, since the flexibility is lost when the thickness is increased, it is desirable to use an arrangement that is possible even when there is no flexibility.

The examples of FIGS. 17 and 18 show a partial structure of a sensor in which a wavelength shift bar 30 is mounted on a side surface of a scintillator 21 and a reflector 24 is arranged around the bar.
When the wavelength shift bar 30 is used, it is necessary to have an air layer around to satisfy the condition of total reflection. However, light from the scintillator 21 is more likely to be incident when it is in close contact with the wavelength shift bar 30. In order to solve this contradictory condition, the wavelength shift bar 30 is made larger (thicker) than the thickness of the scintillator 21 and has a thickness necessary to absorb almost all of the light entering from the scintillator 21 side. Alternatively, it is effective to use a column. The prism has a higher efficiency of capturing fluorescent light generated inside than the cylinder, and thus can collect light more efficiently.

The scintillator 21 and the wavelength shift bar 30 may be in contact with each other with air as a boundary, or when the thickness and the diameter of the wavelength shift bar 30 are clearly larger than the thickness of the scintillator 21, they may be joined closely. When air is used as a boundary, a combination of forming a groove-like cut in a part of the wavelength shift bar 30 and inserting the scintillator 21 in the groove without using an adhesive or the like is also possible.

The wavelength shift bar 30 is not flexible when it is thick, but has a large trapping efficiency and a large amount of condensed light because of a large difference in refractive index from air, which corresponds to cladding. For this reason, a sensor which does not need to bend and arrange the wavelength shift fiber 22 described in the first, fourth, and fifth embodiments can be effectively applied instead of the wavelength shift fiber 22.

Eighth Embodiment (FIG. 19) This embodiment is provided with a prismatic or cylindrical transparent resin or glass wavelength shift bar 30 having a fluorescent function equivalent to that of the wavelength shift fiber 22. The light from the locations is combined and guided to the photodetector 23.

In the example shown in FIG.
Are processed in advance into a shape in which two meet each other, two sets of the wavelength shift bars 30 are mounted on four sides of the scintillator 21, and the photodetectors 23 are mounted on the merging portions.

According to the configuration of the present embodiment, a sensor having a high light-collecting amount and also having optical symmetry can be realized.

Ninth Embodiment (FIGS. 20 and 21) This embodiment is a radiation detecting apparatus using the wavelength shift type radiation sensor according to any of the above-described first to eighth embodiments. When the detection signals obtained from the photodetectors are detected simultaneously, the detection signals are regarded as signals due to radiation, and identification means for identifying other signals as signals such as noise of the photodetectors is provided.

That is, in the apparatus according to the present embodiment, for example, signals output from two systems of photodetectors are taken into the coincidence counting device, and those having the synchronism are radiation signals and have no synchronism. The object is identified as noise of the photodetector 23 or the circuit which is generated at random.

The apparatus shown in FIG. 20 detects a signal output from the photodetector 23, whether it is a noise or a pulse due to radiation, and outputs logic signals A and B, The system is provided with a coincidence counting device 32 for verifying synchronism by taking a logical product of two or more logical signals A and B, and a counting device 33 for counting its output.

The apparatus shown in FIG. 21 shows a configuration in which four photodetectors 23 are used. 20, the signal detection device 31 and the coincidence counting device 32
And a counter 33, and the coincidence device 9 receives four logic signals A, B, C, and D. in this case,
As the type of logical operation, among the four signals A, B, C, and D,
There are options such as establishment of any two, any three, or all four coincidences. Therefore, in order to be able to discriminate noise and to achieve a high detection probability of a signal due to radiation, the condition that any two coincidences are satisfied is usually appropriate. For example, when the noise count rate of the photodetector 23 is high, the logical operation of three simultaneous operations or four simultaneous operations may be effective. In any case, high-accuracy radiation detection can be performed by counting the logical operation output by the counter 13.

Tenth Embodiment (FIG. 22) This embodiment is a radiation detecting apparatus using the above-mentioned wavelength-shifting radiation sensor, wherein the pulse peak value and the threshold value of the output signal of each photodetector are referred to. It is provided with a comparing means for comparing the voltage value and a signal below the threshold value as noise and a signal exceeding the threshold value as a radiation detection signal.

That is, as shown in FIG. 22, the output pulse signal of each photodetector is voltage-amplified to a required level by the amplifier 34, and a voltage pulse output is obtained. This signal V is input to a comparison device 35 as comparison means, and the reference voltage Vre
is compared to f. As long as the pulse peak value is higher than Vref, a logical output is made, thereby serving as a discriminating means. The logical output is counted by the counting device 36.

By setting Vref slightly higher than the level of the photodetector and the circuit noise, all signals exceeding this can be regarded as signals due to radiation.

In the case where the outputs of the wavelength shift fiber 22 are led together by the transmission optical fiber 28 to one photodetector 3, the synchronization cannot be verified. A signal is obtained. Therefore, the present embodiment can be applied as a particularly effective means in such a configuration.

Eleventh Embodiment (FIGS. 23 and 24) In this embodiment, the above-described wavelength shift type radiation sensor is brought into close contact with the upper and lower two layers, and the presence or absence of independent signals output from these upper and lower sensors is determined. The present invention relates to a radiation detection apparatus having means for identifying the type of incident radiation based on the length of its range.

That is, as shown in FIG. 23, two layers of scintillators 21 are provided, and the wavelength shift fibers 22 are independently mounted on each of the scintillators 21 in any of the first to fifth embodiments. .

As described above, when the sensor on the radiation incident surface side (upper side) is the first layer (U) and the lower sensor is the second layer (L), the first layer (U) Is the thickness required when a short-range α-ray loses the total energy or energy close to it. Therefore, when α-rays enter, only the first layer (U) emits light. Since β rays have higher penetrating power on average than α rays, even the first layer (U) penetrates into the second layer (L) while partially losing energy, and remains in the second layer (L). Loses all energy. The thickness of the second layer (L) is determined so that the incident β-ray loses all energy in the first and second layers. Optically, the first
And the second layer are separated from each other so as not to be affected by light emission in the other layers.

According to this configuration, when a signal is output only from the first layer, or when a large signal (having a value equal to or higher than the constant peak value) is detected by adding further conditions, the signal by the α-ray is used. In other cases, it can be identified as a β-ray signal.

FIG. 24 is a truth table of a combination of a state with signal detection (Τ) and a state without signal detection (F) when the upper sensor is expressed as U and the lower sensor is expressed as L. Numbers 0 to 4 are assigned to the four combinations as states, and determination of the first to third cases in which some signal detection is performed is considered. In the case of state 1, α ray is incident, in the case of states 2, 3, β
It can be identified as line incidence.

As state 1, when it is conceivable that β-rays having a lower energy than expected are incident, the peak value at the upper stage (U) is identified. It is also effective to add a β-ray discrimination method for small signals less than that.

Twelfth Embodiment (FIG. 25) This embodiment is a modification of the eleventh embodiment, and a part of the plurality of wavelength shift fibers constituting each sensor closely contacted with the upper and lower two layers is composed of upper and lower two layers. Combination of the detection signal from this common wavelength shift fiber and the presence / absence of independent signals output from each of the upper and lower sensors, so that the light from each scintillator can be received and converted into fluorescence so as to be in contact with each scintillator. Accordingly, the present invention is directed to a radiation detecting apparatus having a means for identifying the type of incident radiation based on the range of the radiation.

As shown in FIG. 25, one part of the wavelength shift fiber 22 (may be the wavelength shift bar 30) is common to the upper and lower stages (22A), and the other one is independent (22A).
B).

In this case, the thicknesses of the first layer (U) and the second layer (L) can be determined in the same way as in the eleventh embodiment. That is, two sets of wavelength shift fibers 22 are provided for one layer of the scintillator 21, one of which is disposed so as to be in contact with both of the two layers of the scintillator. When the light is detected in the above, the synchronism with the detection signal of the light from the remaining two layers of independent wavelength shift fiber or the wavelength shift bar is checked, and if the synchronization is established, the radiation is detected in the corresponding layer. It is thought that it was.

According to this configuration, when a signal is output only from the first layer (U), or when a large (above a certain peak value) signal is detected with additional conditions, α-ray , And in other cases, a β-ray signal. In other words, if there is a coincidence count on the common side and the upper side, it is regarded as signal detection on the upper side, and FIG.
The U (upper row) referred to in 4 is considered to be T. This way,
The line type determination logic is the same as in the eleventh embodiment.

In the state 1, when it is considered that a β-ray having energy lower than the assumed energy is incident, the peak value of the signal obtained from the system in which only the upper stage (U) is independently arranged is identified, It is also effective to add a discrimination method called α-ray when the high value has a signal equal to or more than a certain value, and β-ray for a small signal less than the α-ray.

Thirteenth Embodiment (FIGS. 26 to 28) In the thirteenth embodiment, a layer which emits light by reaction with charged particles is formed on the surface of the scintillator on the radiation incident surface side by optically contacting the scintillator. Amplifying means for amplifying an output signal from the amplifier, comparing means for outputting the amplified signal only when the signal exceeds a certain threshold value, and an output signal from the comparing means and a delayed output signal of the signal by a delay circuit. The present invention relates to a radiation detecting apparatus provided with means for examining a count value of all radiation and a count value for each type of radiation by simultaneous discrimination.

A description will be given with reference to FIGS.
It is assumed that the wavelength shift fiber 22 is attached to the scintillator 21 by any of the methods described above. A plastic scintillator having an extremely short luminescence decay time (10 ns) is applied to the scintillator 21, and a scintillator 21A which emits light with, for example, α-rays and has an extremely long luminescence decay time on its radiation incident surface for detecting charged particles. For example, ZnS (Ag) (emission decay time 10 μm)
s) is applied. When α rays enter, this ZnS
Light is emitted by the scintillator 21A of the (Ag) layer, and emitted by the plastic scintillator 21 when β-rays or γ-rays enter.

The light from the wavelength shift fiber 22 is sent to the photodetector 23 with the maximum amount of light. The amplifying device 34 amplifies the peak value so that the peak value becomes a voltage level within a certain range. Here, the gain of the amplifying device 34 operates so as to be large for a small signal and small for a large signal. As a result, the output signal is a signal a having a pulse height within a certain range. Becomes The signal a is input to the comparison device 35, and a logical output b is obtained only when the signal a exceeds the reference voltage value. The pulse width of this logical output pulse is short due to the light from the plastic scintillator because the peak value is within a substantially constant range, and ΔnS (Δg)
Light from the light source is significantly longer.

Therefore, as shown in FIG. 27, the logical product of the logical output pulse (b) by the pulse width discriminating device 37 and the logical output pulse (c) delayed by the time Td through the delay device 37 is discriminated by the discriminating device. Take at 39. FIG. 28 shows a timing chart at this time.

In FIG. 28, the delay time Td is larger than the decay time (10 ns) of the plastic scintillator and Z
It is set to a value smaller than that of nS (Ag). If the pulse width is short, the logical product with the delayed pulse is FALSE, but if the pulse is wide, the logical product output is TR
Become a UE.

Therefore, by counting the output of the comparison device 35 and subtracting the logical product output as the α-ray count value, the total count, α-ray and β-ray count values can be obtained. Although a dedicated circuit for discriminating the rise time of a pulse has been practically used, it is complicated and expensive, and can be applied only to a pulse having a sufficient light quantity.

However, in this embodiment, since the purpose is only to discriminate between two types of pulses having greatly different rise times, discrimination can be performed by such an apparatus having a very simple circuit configuration.

Fourteenth Embodiment (FIGS. 29 to 31) In this embodiment, the periphery of another flat scintillator instead of the reflector is closely attached to the non-contact surface of the wavelength shift fiber or the wavelength shift bar to the scintillator. This is for the wavelength shift type radiation sensor. That is, a plurality of scintillators 21 are combined, and their boundaries and end faces are set to the wavelength shift fiber 22 (or the wavelength shift bar 30).
And the sensing area is enlarged.

As shown in FIG. 29, three rectangular plate-like scintillators 1 are joined, a wavelength shift fiber 22 is sandwiched between them, and attached to two sides on both sides. A reflector 24 is provided at one end of each wavelength shift fiber 22.
, And a photodetector 23 is attached to the other end face. In this case, four (a, b, c, and d) photodetectors 23 are used, and optical symmetry is obtained by mounting them at opposing positions.

In some cases, the scintillator 1 is further divided as shown by a broken line in the figure, a wavelength shift fiber 22 is also sandwiched in the longitudinal direction, and four photodetectors 2
3 (e, f, g, h) may be provided. In this way, the structure can be expanded by the required sensing area. According to this, it is possible to increase the area without deteriorating the sensitivity and its position-dependent production.
As shown in FIGS. 30 and 31, also in this case, the transmission optical fiber 30 can connect between the wavelength shift fiber 22 and the photodetector 23. In particular, a large detector has a large weight, so that the advantage of remote electronic circuits is great.

Fifteenth Embodiment (FIGS. 32 and 33) This embodiment is a radiation detection apparatus using the wavelength shift type radiation detection sensor of the fourteenth embodiment, and includes two systems out of a plurality of light detection signals. When the detection signals obtained from the photodetectors are detected at the same time, it is regarded as a signal due to radiation,
The present invention relates to a radiation detection apparatus provided with an identification unit that identifies other signals as signals such as noise of a photodetector.

In this embodiment, although the whole is constituted by a plurality of scintillators 21, the whole is regarded as one sensor, and a logic for outputting a signal when radiation is incident on any of the scintillators 21 is used. .

That is, as shown in FIG. 32, in the present embodiment, a logical operation device 40 and a counting device 41 as identification means are provided, and in the sensor, the photodetectors 23 are a, b, c,
When the light from the d portion is observed, the sum of the logical product of two adjacent wavelength-shifting fibers 21 is identified and counted.

FIG. 33 shows a logical operation device 40 in which three adjacent
It identifies the sum of two logical products.

As described above, by using the logic device 40, even when a plurality of scintillators 21 are combined,
The measurement can be performed as if the entire surface were regarded as one continuous surface.

Sixteenth Embodiment (FIGS. 34 and 35) This embodiment uses the wavelength shift type radiation detection sensor of the fourteenth embodiment, and detects a plurality of light detection signals obtained from two systems of photodetectors. When signals are detected simultaneously, it is regarded as a signal due to radiation, other signals are identified as signals such as noise of the photodetector, etc., and the scintillator to which the radiation is incident is identified by the combination of the detected wavelength shift fiber. This is for a radiation detection device having a function of performing

In this embodiment, a plurality of scintillators 21
Is not considered as a single detector, but logic that outputs an independent signal for each scintillator when radiation enters each of the scintillators is used.

That is, as shown in FIGS. 34 and 35,
In this embodiment, a logical operation device 41 is provided, and the photodetector 23 is provided.
Is observing light from portions corresponding to the a, b, c, d, e, f, g, and h portions, and when the photodetectors 23 around one of the divided scintillators 21 perform simultaneous counting. Is recognized as a signal on the surface, and the incident position of the radiation can be identified as independent position-specific signals equal in number to the number of divisions of the scintillator 21.

[0161]

As described above, according to the present invention, an apparatus for detecting radiation, in particular β-rays, which is small, thin and lightweight, has high sensitivity by being optically symmetric, and has a small position dependency. Can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a wavelength shift type radiation sensor according to a first embodiment of the present invention.

FIG. 2 is a side view of the wavelength shift type radiation sensor shown in FIG.

FIG. 3 is an enlarged view showing a configuration example of a wavelength shift fiber unit according to the first embodiment.

FIG. 4 is an enlarged view showing another configuration example of the wavelength shift fiber unit in the first embodiment.

FIG. 5 is an enlarged view showing still another configuration example of the wavelength shift fiber unit in the first embodiment.

FIG. 6 is an enlarged view showing another configuration example of the wavelength shift fiber section in the first embodiment.

FIG. 7 is a perspective view showing a wavelength shift type radiation sensor according to a second embodiment of the present invention.

FIG. 8 is a perspective view showing a wavelength shift type radiation sensor according to a third embodiment of the present invention.

FIG. 9 is a perspective view showing a wavelength shift type radiation sensor according to a fourth embodiment of the present invention.

FIG. 10 is a perspective view showing a wavelength shift type radiation sensor according to a fifth embodiment of the present invention.

FIG. 11 is a view showing an example of a fiber connection structure as a sixth embodiment of the wavelength shift type radiation sensor according to the present invention.

FIG. 12 is a view showing another example of a fiber connection structure as a sixth embodiment of the wavelength shift type radiation sensor according to the present invention.

FIG. 13 is a diagram showing another example of a fiber connection structure as a sixth embodiment of the wavelength shift type radiation sensor according to the present invention.

FIG. 14 is a diagram showing an example of a connection structure between a fiber and a photodetector as a sixth embodiment of the wavelength shift type radiation sensor according to the present invention.

FIG. 15 is a view showing another example of a connection structure between a fiber and a photodetector as a sixth embodiment of the wavelength shift type radiation sensor according to the present invention.

FIG. 16 is a view showing another example of a connection structure between a fiber and a photodetector as a sixth embodiment of the wavelength shift type radiation sensor according to the present invention.

FIG. 17 is a diagram showing an example of a wavelength shift bar connection structure as a seventh embodiment of the wavelength shift type radiation sensor according to the present invention.

FIG. 18 is a view showing another example of a wavelength shift bar connection structure as a seventh embodiment of the wavelength shift type radiation sensor according to the present invention.

FIG. 19 is a diagram showing a connection structure of a wavelength shift bar as an eighth embodiment of the wavelength shift type radiation sensor according to the present invention.

FIG. 20 is a ninth embodiment of the radiation detecting apparatus according to the present invention.
FIG. 1 is a diagram illustrating a configuration example of an embodiment.

FIG. 21 is a ninth view of the radiation detection apparatus according to the present invention.
FIG. 6 is a diagram illustrating another configuration example of the embodiment.

FIG. 22 is a first diagram illustrating the radiation detection apparatus according to the present invention;
The system diagram which shows 0 embodiment.

FIG. 23 is a first diagram illustrating the radiation detecting apparatus according to the present invention;
FIG. 1 is a configuration diagram showing one embodiment.

FIG. 24 is an operation explanatory view of the system shown in FIG. 23;

FIG. 25 is a first diagram illustrating the radiation detection apparatus according to the present invention;
The block diagram which shows 2nd Embodiment.

FIG. 26 shows a first example of the radiation detecting apparatus according to the present invention.
The system diagram which shows 3rd Embodiment.

FIG. 27 is a diagram showing a continuation of the signal system in FIG. 26;

FIG. 28 is an operation explanatory view of the system shown in FIGS. 25 and 26;

FIG. 29 is a configuration diagram showing a fourteenth embodiment of the wavelength shift type radiation sensor according to the present invention.

FIG. 30 is a diagram showing the fiber connection structure of FIG. 29;

FIG. 31 is a diagram showing the fiber connection structure of FIG. 29;

FIG. 32 shows a first example of the radiation detecting apparatus according to the present invention.
The figure which shows one system example by 5th Embodiment.

FIG. 33 is a first diagram illustrating the radiation detection apparatus according to the present invention;
The figure which shows the other example of a system by 5th Embodiment.

FIG. 34 is a first diagram illustrating the radiation detection apparatus according to the present invention;
The figure which shows one system example by 6th Embodiment.

FIG. 35 is a first view of the radiation detection apparatus according to the present invention.
The figure which shows the other example of a system by 6th Embodiment.

FIG. 36 is a diagram showing an example of a conventional configuration.

FIG. 37 is a diagram showing another conventional configuration example.

FIG. 38 is a diagram showing another conventional configuration example.

FIG. 39 is a diagram showing still another example of the conventional configuration.

FIG. 40 is a diagram for explaining a use state of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Scintillator 22 Wavelength shift fiber 22a, 24, 25 Reflector 23 Photodetector 26 Reflection / light shielding material 27 Transparent medium 28 Transmission optical fiber 29 Light receiving part 30 Wavelength shift bar 31 Signal detection device 32 Simultaneous counting device 33 Counting device 34 Amplifying device 35 comparison device 36 counting device 37 pulse width discriminating device 39 discriminating device 40 logical operation device 41 counting device

Claims (16)

[Claims] 1. A wavelength having a plate-shaped scintillator and a wavelength-shifting fiber which is connected at least partially to the periphery of the scintillator in optically close contact with the scintillator and absorbs scintillation light and emits light having a long wavelength. In the shift type radiation sensor, the wavelength shift fiber is composed of a plurality of wavelength shift fibers symmetrically arranged along the periphery of the scintillator, and a photodetector is mounted on one end surface of each wavelength shift fiber in the longitudinal direction. A reflector is provided on the other end surface for returning light into the wavelength shift fiber, and the outer surface of the wavelength shift fiber is not in contact with the scintillator, and the outer surface of the periphery of the scintillator where the wavelength shift fiber is not provided, A reflector that reflects light toward the inside of the scintillator is provided, while a flat surface of the scintillator is refracted. A substance whose ratio is smaller than that of the scintillator is provided, and a reflection / light-shielding material capable of reflecting light emitted from the scintillator to the inside of the scintillator and shielding light from the outside is further provided on the outside of the surface. The wavelength shift type radiation sensor, wherein the reflection / shielding material is capable of transmitting the radiation to be measured at least on the radiation incident side of the scintillator. 2. A wavelength having a plate-shaped scintillator and a wavelength-shifting fiber which is connected at least partially to the periphery of the scintillator in optically close contact, absorbs scintillation light and emits light having a long wavelength. In the shift type radiation sensor, the wavelength-shifting fibers are two or more and surround the entire periphery of the scintillator with them, and a photodetector is attached to one end surface in the longitudinal direction of each wavelength-shifting fiber and the other end surface. A reflector for returning light into the wavelength shifting fiber is provided, and a reflector that reflects light toward the inside of the scintillator is provided on an outer surface of the wavelength shifting fiber that is not in contact with the scintillator, A substance whose refractive index is smaller than that of the scintillator is provided on a flat surface of the scintillator, and On the outside, a reflective / light-shielding material capable of blocking light from the outside while reflecting light emitted from the scintillator toward the inside of the scintillator,
The reflection / shielding material is capable of transmitting radiation to be measured on at least the radiation incident side of the scintillator, and is a wavelength shift type radiation sensor. 3. A wavelength having a plate-shaped scintillator and a wavelength-shifting fiber that is at least partially optically connected to a peripheral portion of the scintillator and that absorbs scintillation light and emits light having a long wavelength. In the shift type radiation sensor, the wavelength shift fiber is made to be one, thereby surrounding the entire periphery of the scintillator, and a photodetector is attached to both longitudinal end faces of the wavelength shift fiber, and the wavelength shift fiber is attached. A reflector that reflects light toward the inside of the scintillator is provided on the outer surface of the fiber that is not in contact with the scintillator, while a substance having a smaller refractive index than the scintillator is provided on the flat surface of the scintillator. Further, outside the surface, the light emitted from the scintillator is reflected toward the inside of the scintillator, and A wavelength-shifting radiation sensor, wherein a reflection / light-shielding material capable of shielding light from the outside is covered, and the reflection / light-shielding material is capable of transmitting radiation to be measured on at least the radiation incident side of the scintillator. 4. A wavelength having a plate-shaped scintillator and a wavelength-shifting fiber that is at least partially optically connected to a peripheral portion of the scintillator and absorbs scintillation light and emits light having a long wavelength. In the shift type radiation sensor, the wavelength shift fiber is arranged in two opposing portions of the periphery of the scintillator as two fibers,
Photodetectors are attached to both end surfaces in the longitudinal direction of each wavelength-shifting fiber, and the outer surface of the wavelength-shifting fiber with respect to the non-contact with the scintillator, and the outer surface of the peripheral edge of the scintillator where the wavelength-shifting fiber is not provided, While a reflector that reflects light inward of the scintillator is provided, a substance whose refractive index is smaller than that of the scintillator is provided on a flat surface of the scintillator, and a substance exiting from the scintillator is provided outside the surface. Reflected light to the inside of the scintillator and shield the light from the outside by a reflective / light-shielding material, which can transmit the radiation to be measured on at least the radiation incident side of the scintillator. A wavelength-shifting radiation sensor, characterized in that: 5. A wavelength having a plate-shaped scintillator and a wavelength-shifting fiber that is connected at least partially to the peripheral edge of the scintillator in optically close contact, absorbs scintillation light, and emits light with a long wavelength. In the shift type radiation sensor, the scintillator is polygonal, the wavelength shift fibers are arranged on each edge thereof, and a photodetector is attached to one end face in the length direction of each wavelength shift fiber, and the other end face is attached to the other end face. Reflectors for returning light into the wavelength shift fiber are provided respectively,
And on the outer surface of each wavelength-shifted fiber with respect to the non-contact of the scintillator, a reflector that reflects light toward the inside of the scintillator is provided, while on the flat surface of the scintillator, the refractive index is higher than that of the scintillator. A small substance is provided, and a reflective / light-shielding material capable of reflecting light emitted from the scintillator to the inside of the scintillator and blocking light from the outside while covering the outside of the surface is further provided. Is a wavelength-shifting radiation sensor, wherein radiation to be measured can be transmitted at least on the radiation incident side of the scintillator. 6. The wavelength-shifting radiation sensor according to claim 1, wherein the wavelength-shifting fiber and the photodetector are a transparent optical fiber, a light guide,
Or connected by means of light transmission comprising a light pipe, and wherein the photodetector has an independent configuration for individually receiving optical signals from the wavelength shift fiber, or a common configuration for collectively receiving optical signals from the wavelength shift fiber. Wavelength shift type radiation sensor. 7. The wavelength-shifting radiation sensor according to claim 1, wherein the wavelength-shifting fiber is replaced with a prismatic or cylindrical transparent resin or glass having a fluorescent function equivalent to that of the wavelength-shifting fiber. A wavelength shift type radiation sensor comprising a wavelength shift bar. 8. The wavelength shift type radiation sensor according to claim 5, wherein a wavelength shift bar made of a prismatic or cylindrical transparent resin or glass having a fluorescent function equivalent to the wavelength shift fiber is used instead of the wavelength shift fiber. A wavelength-shifting radiation sensor, comprising: light from two or more of the wavelength-shifting bars combined and guided to a photodetector. 9. A radiation detection apparatus using the wavelength shift type radiation sensor according to claim 1, wherein the detection signals obtained from the two systems of photodetectors are detected at the same time. A radiation detection apparatus comprising: identification means that regards signals as radiation and identifies other signals as signals such as noise of a photodetector. 10. A radiation detecting apparatus using the wavelength shift type radiation sensor according to claim 1, wherein a pulse peak value of an output signal of each photodetector and a reference voltage serving as a threshold value. A radiation detecting apparatus comprising: comparing means for comparing a value with a value; and identifying means for identifying a signal less than a threshold value as noise and identifying a signal exceeding the threshold value as a radiation detection signal. 11. The incident radiation according to a combination of the presence and absence of independent signals output from the upper and lower sensors, wherein the wavelength-shifting radiation sensor according to any one of claims 1 to 8 is closely attached to upper and lower layers. A radiation detecting apparatus having means for identifying the type of the object based on the length of the range. 12. The wavelength-shifting radiation sensor according to claim 1, 2, 4, 5, 6, 7, or 8 is adhered to upper and lower two layers, and one of a plurality of wavelength-shifting fibers constituting each of these sensors. The section is configured to be in contact with each scintillator so that light from any of the upper and lower scintillators can be received and converted into fluorescence, and the detection signal from this common wavelength shift fiber and the independent signal output from each of the upper and lower sensors A radiation detection apparatus comprising means for identifying the type of incident radiation based on the range of the incident radiation by a combination of presence and absence of a signal. 13. A radiation detecting apparatus using the wavelength-shifting radiation sensor according to claim 1, wherein the scintillator emits light on the surface on the radiation incident surface side by reaction with charged particles. Amplifying means for amplifying an output signal from the photodetector, optically contacting the layer, a comparing means for outputting the amplified signal only when the signal exceeds a certain threshold, and an output from the comparing means. A radiation detection apparatus comprising means for examining a count value of all radiation and a count value for each type of radiation by simultaneously discriminating a signal and a delayed output signal of the signal by a delay circuit. 14. The scintillator according to claim 1, wherein the non-contact surface of the wavelength shift fiber or the wavelength shift bar with respect to the scintillator is replaced with another flat scintillator instead of the reflector. A wavelength-shifting radiation sensor characterized in that the peripheral edge of the radiation sensor is in close contact. 15. A radiation detection apparatus using the wavelength shift type radiation detection sensor according to claim 14, wherein, among the plurality of light detection signals, detection signals obtained from two systems of photodetectors are detected simultaneously. Is considered to be a signal due to radiation,
A radiation detection apparatus comprising identification means for identifying other signals as signals such as noise of a photodetector. 16. A radiation detection apparatus using the wavelength shift type radiation detection sensor according to claim 14, wherein detection signals obtained from two systems of photodetectors are simultaneously detected among the plurality of photodetection signals. Is considered to be a signal due to radiation,
A radiation detection device having a function of identifying other signals as signals such as noise of a photodetector and identifying a scintillator on which radiation is incident by a combination of wavelength-shifted fibers for which signals have been detected.