JP2009047624A - Radiation detection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation detection apparatus that allows high sensitivity measurement of γ-rays under a high temperature environment and that can also suppress degradation of components. <P>SOLUTION: This radiation detection apparatus includes a cylindrical light-emitting element 1 onto which γ-rays 6 are incident, a cylindrical condensing element 2 for condensing light 7 from the light-emitting element 1; a cylindrical vessel 14 where the cross section is elliptical and inner wall forms a mirror surface, the light-emitting element 1 is installed at or near one focal position of the elliptical mirror surface, and the condensing element 2 is installed at or near the other focal position; a light transmission cable 3, that is connected to the condensing element 2 and leads out the light 7 to the outside; a photodetector 4, that is installed in an environment of a temperature which is lower than that of the light-emitting element 1, is connected to the other end of the light transmission cable 3, and detects the light 7; and a signal processing circuit 5 for converting the detected light 7 into a signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radiation detection apparatus that detects radiation in a high temperature environment.

  A scintillation detector is known as a radiation detection device that detects radiation in a high-temperature environment (see, for example, Patent Document 1).

This scintillation detector includes a scintillator that emits light having an intensity substantially proportional to incident γ-ray energy, a photomultiplier that detects the light and converts it into an electric signal, and a signal processing circuit that processes the electric signal. It is configured. A scintillation detector usually has a structure in which a photomultiplier tube is directly joined to a scintillator in order to increase the amount of received light.
JP-A-56-785

  The conventional scintillation detector described above employs a structure in which a photomultiplier tube is directly joined to the scintillator in order to increase the amount of received light.

  For this reason, when the scintillation detector is installed in a high temperature environment, the photomultiplier tube is affected by the high temperature, and the output signal fluctuates and the components deteriorate. That is, when this scintillation detector is installed in a high temperature environment, the photomultiplier tube is affected by the high temperature, and there is a problem that it is difficult to measure gamma rays with high sensitivity in a high temperature environment.

  In addition, when this scintillation detector is installed in a high temperature environment, there is a problem in that deterioration of components of the radiation detection device is promoted.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a radiation detection apparatus that can measure gamma rays with high sensitivity in a high-temperature environment and can further suppress deterioration of components. To do.

  In order to achieve the above object, in the radiation detection apparatus of the present invention, a cylindrical light emitting element on which radiation is incident, a cylindrical light collecting element for condensing light from the light emitting element, and an elliptical cross section A cylindrical container in which the inner wall forms a mirror surface, the light emitting element is installed at or near one focal position of the elliptical mirror surface, and the light collecting element is installed at or near the other focal position. A light transmission cable connected to the light condensing element to guide the light to the outside, and a light detector installed in a lower temperature environment than the light emitting element and connected to the other end of the light transmission cable to detect the light And a signal processing circuit for converting the detected light into a signal.

  In order to achieve the above object, in the radiation detection apparatus of the present invention, a light emitting element on which radiation is incident, a concave mirror disposed at least at one end of the light emitting element and toward the light emitting surface of the light emitting element, A condensing element that is provided at or near the focal position of the concave mirror and condenses light from the light emitting element, and is installed in a lower temperature environment than the light emitting element and is connected to the other end of the light transmission cable and the light. And a signal processing circuit for converting the detected light into a signal.

  According to the radiation detection apparatus of the present invention, the light emitting element is installed at one focal position of the elliptical cylindrical container or in the vicinity thereof, and the light collecting element is installed at the other focal position or in the vicinity thereof. It is possible to measure gamma rays with high sensitivity below.

  In addition, by connecting a light detector to the condensing element via a light transmission cable and detecting light, the influence of the high temperature environment is greatly limited in the light detector, and deterioration of components can be suppressed.

  Hereinafter, embodiments of a radiation detection apparatus according to the present invention will be described with reference to the drawings. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted.

  FIG. 1 is a block diagram showing the configuration of the radiation detection apparatus according to the first embodiment of the present invention, and FIG. 2 shows the configuration of a modification of the radiation detection apparatus according to the first embodiment of the present invention. It is a perspective view.

  First, the structure of the radiation detection apparatus of 1st Embodiment is demonstrated using FIG. 1, FIG.

  As shown in FIGS. 1 and 2, the radiation detection apparatus includes a cylindrical light-emitting element 1 that is installed in a high-temperature environment and that receives γ-rays 6 or X-rays that are high-energy radiation. And a cylindrical container 14 in which the light emitting element 1 and the light collecting element 2 are built. As an example, a scintillator is used as the light emitting element 1. In addition, as an example, the cylindrical container 14 has an elliptical cross section, and an inner wall forms a mirror surface. The light emitting element 1 is installed at or near one focal position of the elliptical mirror surface, and the other focal position or this The condensing element 2 is installed in the vicinity.

  At the other end of the light transmission cable 3 to which the condensing element 2 is connected, a photodetector 4 that is installed in a lower temperature environment than the light emitting element 1 and detects the light 7 is provided.

  In the present embodiment configured as described above, when the radiation detection apparatus is installed at a measurement place in a high temperature environment, when γ rays 6 or X rays, which are high energy radiation, are incident on the light emitting element 1. The light emitting element 1 emits light 7 by excitation energy. The light 7 from the light emitting element 1 installed at or near one focal position of the cylindrical container 14 having an elliptical cross-sectional shape is reflected by the mirror surface forming the inner wall of the cylindrical container 14, and the other of the cylindrical container 14 Is incident on the condensing element 2 installed at or near the focal position.

  The other end of the light transmission cable 3 connected to the condensing element 2 is connected to a photodetector 4 that is installed in a lower temperature environment than the light emitting element 1 and detects the light 7 from the light transmission cable 3.

  According to the present embodiment, the light emitting element 1 is disposed at one focal position of the cylindrical container 14 or in the vicinity thereof, and the light collecting element 2 is disposed at the other focal position or in the vicinity thereof. It increases the collection efficiency and expands the range of detectable radiation dose, enabling highly sensitive gamma ray measurement in high temperature environments.

  Further, the photodetector 4 is connected to the condensing element 2 via the light transmission cable 3 and the incident light 7 is detected, so that the influence of the high temperature environment is greatly limited in the photodetector 4, and the components Can be prevented.

  Next, a modification of the radiation detection apparatus according to the first embodiment will be described with reference to FIG. FIG. 2 is provided by adding a repeater 8 to the radiation detection apparatus of FIG. 1, and the same or similar parts as in FIG.

  As shown in the figure, a glass wavelength shift fiber 15 that is a wavelength conversion fiber is used as a condensing element. The irradiated light 7 is confined inside the glass wavelength shift fiber 15. The glass wavelength shift fiber 15 is connected to the optical transmission cable 3 via the repeater 8. The light 7 is led out to the outside by the optical transmission cable 3. A light detector 4 (see also FIG. 1) is connected to the other end of the light transmission cable 3.

  According to the present embodiment, the irradiated light 7 is confined inside the glass wavelength shift fiber 15, and the light 7 is led out to the outside by the light transmission cable 3 connected to the glass wavelength shift fiber 15. The photodetector 4 to which the optical transmission cable 3 is connected is greatly limited in the influence of the high temperature environment and can suppress the deterioration of the components.

  FIG. 3 is a front view partially showing the configuration of the radiation detection apparatus according to the second exemplary embodiment of the present invention.

  First, the structure of the radiation detection apparatus of 2nd Embodiment is demonstrated using FIG.

  As shown in the figure, the radiation detection apparatus is installed in a high-temperature environment and a light emitting element 16 on which γ rays 6 are incident, and at least one end of the light emitting element 16 and toward the light emitting surface of the light emitting element 16. And a condensing element 2 that condenses the light 7 from the light emitting element 16 provided at or near the focal position of the concave mirror 9. An optical transmission cable 3 is connected to the condensing element 2. The other end of the light transmission cable 3 is connected to a photodetector 4 (see also FIG. 1) that is installed in a lower temperature environment than the light emitting element 16 and detects the light 7.

  According to the present embodiment, the concave mirror 9 is installed toward the light emitting surface of the light emitting element 1, and the condensing element 2 is installed at or near the position where the focal point of the concave mirror 9 is focused to improve the condensing efficiency of the reflected light 7. By increasing it, the range of detectable radiation dose can be expanded. Further, by detecting the reflected light 7 through the light transmission cable 3, it is possible to measure the highly sensitive γ-ray 6 in a high temperature environment.

  FIG. 4 is a front view partially showing a configuration of a modification of the radiation detection apparatus according to the second exemplary embodiment of the present invention. FIG. 4 is obtained by adding a through hole 9a to the concave mirror 9 of FIG. 3, and the same or similar parts as in FIG.

  As shown in the figure, the radiation detection apparatus is installed in a high-temperature environment and a light emitting element 16 on which γ rays 6 are incident, and at least one end of the light emitting element 16 and toward the light emitting surface of the light emitting element 16. And a condensing element 2 that condenses the light 7 from the light emitting element 16 provided at or near the focal position of the concave mirror 9. A through hole 9 a is opened at the center of the concave mirror 9. The light transmission cable 3 connected to the condensing element 2 is taken out through the through hole 9a. The other end of the light transmission cable 3 is connected to a photodetector 4 (see also FIG. 1) that is installed in a lower temperature environment than the light emitting element 16 and detects the light 7.

  According to the present embodiment, the light transmission cable 3 is taken out via the through hole 9 a opened at the center of the concave mirror 9. For this reason, since the light 7 from the light emitting element 16 is not blocked by the cable, the light collection efficiency can be increased. Further, by detecting the reflected light 7 through the light transmission cable 3, it is possible to measure the highly sensitive γ-ray 6 in a high temperature environment.

  FIG. 5: is sectional drawing which shows the structure of the other modification of the radiation detection apparatus of the 2nd Embodiment of this invention. 5 is obtained by adding a through hole 16a to the light emitting element 16 of FIG. 3, and the same or similar parts as in FIG.

  As shown in the figure, the radiation detection apparatus is installed in a high-temperature environment and a light emitting element 16 on which γ rays 6 are incident, and at least one end of the light emitting element 16 and toward the light emitting surface of the light emitting element 16. And a condensing element 2 that condenses the light 7 from the light emitting element 16 provided at or near the focal position of the concave mirror 9. A through hole 16 a is opened at the central axis of the light emitting element 16. The light transmission cable 3 connected to the condensing element 2 is taken out through the through hole 16a. The other end of the light transmission cable 3 is connected to a photodetector 4 that is installed in a lower temperature environment than the light emitting element 16 and detects the light 7.

  According to the present embodiment, the light transmission cable 3 is taken out to the outside through the through-hole 16a opened in the central axis of the light emitting element 16. For this reason, since it does not open to the concave mirror 9, a condensing efficiency can be improved. Further, by detecting the reflected light 7 through the light transmission cable 3, it is possible to measure the highly sensitive γ-ray 6 in a high temperature environment.

  FIG. 6 is a front view showing a configuration of still another modified example of the radiation detection apparatus according to the second exemplary embodiment of the present invention. FIG. 6 is obtained by adding the joint portion 10 to the light emitting element 16 of FIG. 3, and the same or similar parts as in FIG.

  As shown in the figure, the radiation detection apparatus is installed in a high temperature environment and is provided with a light emitting element 16 on which γ rays 6 are incident, and one end of the light emitting element 16 and toward the light emitting surface of the light emitting element 16. A concave mirror 9 and a condensing element 2 that condenses the light 7 from the light emitting element 1 provided at or near the focal position of the concave mirror 9 are provided. Between the light emitting element 1 and the concave mirror 9, a joint 10 made of a stretchable material is provided.

  According to the present embodiment, by providing the stretchable joint 10 between the light emitting element 16 and the concave mirror 9, damage to the joint surface due to the difference in thermal expansion coefficient between the light emitting element 16 and the concave mirror 9 is prevented. This makes it possible to measure gamma rays with high sensitivity in a high temperature environment.

  FIG. 7 is a front view showing a part of the configuration of the radiation detection apparatus according to the third exemplary embodiment of the present invention.

  FIG. 7 is provided by adding a mirror 11 inside the concave mirror 9 of FIG. 3, and the same or similar parts as in FIG.

  As shown in the figure, the radiation detection apparatus is installed in a high-temperature environment and a light emitting element 16 on which γ rays 6 are incident, and at least one end of the light emitting element 16 and toward the light emitting surface of the light emitting element 16. A concave mirror 9 and a mirror 11 provided at or near the focal position of the concave mirror 9 to collect the light 7 from the light emitting element 16. The light 7 from the mirror 11 passes through a through hole 9 b provided at the center of the concave mirror 9, is collected by a lens 12 provided outside the concave mirror 9, and is incident on the light transmission cable 3.

  According to the present embodiment, the light collected by the concave mirror 9 is reflected by the mirror 11 installed in the vicinity of the focal point, and is incident on the light transmission cable 3 via the through hole 9 b provided in the center of the concave mirror 9. . Thus, the light collection efficiency can be further enhanced by eliminating the attenuation of light when passing through the light collecting element 2. Further, by detecting the reflected light 7 through the light transmission cable 3, it is possible to measure the highly sensitive γ-ray 6 in a high temperature environment.

  FIG. 8 is a front view showing the configuration of the radiation detection apparatus according to the fourth embodiment of the present invention.

  8 is provided with concave mirrors 9 and 13 on both surfaces of the light emitting element 1 of FIG. 3, and the same or similar parts as in FIG.

  As shown in the figure, the radiation detection apparatus is installed in a high temperature environment and a light emitting element 16 on which γ rays 6 are incident, and on both surfaces of the light emitting element 16 and toward the light emitting surface of the light emitting element 16. Concave mirrors 9 and 13, and condensing elements 2 and 2 a that are provided at or near the focal positions of the concave mirrors 9 and 13 and collect the light 7 from the light emitting element 16. The light transmission cables 3 and 3a are connected to the condensing elements 2 and 2a, respectively. The other ends of the light transmission cables 3 and 3 a are connected to a photodetector 4 (see also FIG. 1) that is installed in a lower temperature environment than the light emitting element 16 and detects the light 7.

  According to the present embodiment, the condensing efficiency can be further increased by providing the concave mirrors 9 and 13, the condensing elements 2 and 2 a, and the light transmission cables 3 and 3 a on both surfaces of the light emitting element 1.

  The embodiments of the present invention have been described above. However, the present invention is not limited to the embodiments described above, and departs from the gist of the present invention by combining the configurations of the embodiments. Various modifications can be made without departing from the scope.

The block diagram which shows the structure of the radiation detection apparatus of the 1st Embodiment of this invention. The perspective view which shows the structure of the modification of the radiation detection apparatus of the 1st Embodiment of this invention. The front view which shows a structure of the radiation detection apparatus of the 2nd Embodiment of this invention partially transparently. The front view which shows a part seeing through the structure of the modification of the radiation detection apparatus of the 2nd Embodiment of this invention. Sectional drawing which shows the structure of the other modification of the radiation detection apparatus of the 2nd Embodiment of this invention. The front view which shows a part seeing through the structure of the further another modification of the radiation detection apparatus of the 2nd Embodiment of this invention. The front view which shows a part of structure of the radiation detection apparatus of the 3rd Embodiment of this invention seeing through partially. The front view which shows a structure of the radiation detection apparatus of the 4th Embodiment of this invention partially transparently.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Light emitting element 2, 2a ... Condensing element 3, 3a ... Optical transmission cable, 4 ... Photo detector, 5 ... Signal processing circuit, 6 ... Gamma ray, 7 ... Light, 8 ... Repeater, 9, 13 DESCRIPTION OF SYMBOLS ... Concave mirror, 9a, 9b ... Through-hole, 10 ... Joint part, 11 ... Mirror, 12 ... Lens, 14 ... Cylindrical container, 15 ... Glass wavelength shift fiber, 16 ... Light emitting element, 16a ... Through-hole.

Claims (4)

A cylindrical light emitting element to which radiation is incident;
A cylindrical condensing element for condensing light from the light emitting element;
The cross section is elliptical and the inner wall forms a mirror surface. The light emitting element is installed at or near one focal position of the elliptical mirror surface, and the light collecting element is installed at or near the other focal position. A cylindrical container;
A light transmission cable connected to the condensing element and leading the light to the outside;
A light detector installed in a low temperature environment than the light emitting element and connected to the other end of the light transmission cable to detect the light;
A signal processing circuit for converting the detected light into a signal;
A radiation detection apparatus comprising:   The radiation detection apparatus according to claim 1, wherein the condensing element includes a wavelength conversion fiber that is optically connected to the optical transmission cable. A light emitting element to which radiation is incident;
A concave mirror installed on at least one end of the light emitting element and toward the light emitting surface of the light emitting element;
A condensing element for condensing light from the light emitting element provided at or near the focal position of the concave mirror;
A light detector installed in a low temperature environment than the light emitting element and connected to the other end of the light transmission cable to detect the light;
A signal processing circuit for converting the detected light into a signal;
A radiation detection apparatus comprising:   The radiation detection apparatus according to claim 3, wherein the light transmission cable is taken out of the concave mirror through a through hole opened at a substantially center of the concave mirror.

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