JPS58206995A - Radiant ray detector - Google Patents

Abstract

PURPOSE:To prevent deterioration of detection accuracy of a multi-channel type photodiode and the whole radiant ray detector, by forming a light output face of a scintillator element positioned at both ends to the same shape as the photodetecting face of a corresponding photodetector. CONSTITUTION:The light output face (bottom face) of scintillator elements 5A, 5E is notched toward the bottom face from the side so that its shape becomes same as the photodetecting face of photodetectors 3A, 3E. According to such a constitution, even if X-rays of the same X-ray quantity are made incident, fluorescent light generated by the scintillator elements 5A, 5E can be led completely to the photodetecting face of the photodetectors 3A, 3E, therefore, decrease of detection accuracy of an X-ray detector 1 can be prevented. Also, since an area of the light output face of the scintillator elements 5A, 5E is made small, the photodetecting face of the photodetectors 3A, 3E is available as it is small and it is unnecessary to lengthen the length of the longitudinal direction of a semiconductor layer 2, therefore, even if plural X-ray detectors 1 are arrayed one-dimensionally, the X-ray incident face of each scintillator can be arrayed at the same pitch, and deterioration of detection accuracy of the whole X-ray detector 1 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention belongs to the technical field of radiation detectors having a scintillator and a multi-channel photodiode.

[Technical background of the invention and its problems]

Radiation tomography devices For example, 6th generation or 4th generation X-ray CT devices have an In recent years, solid-state scintillation detectors that combine a scintillator and a photodiode have become widely used instead of gas ionization chambers, which have traditionally been the mainstream. This is because diodes can be mounted in high density, so it is possible to meet the requirement that the array pitch of the detection elements must be made as small as possible in order to obtain a high-resolution 01 image.

As shown in FIG. 1, the X-ray detector 1 includes a plurality of light receiving elements on a semiconductor layer 2.3. (-3E is arranged in the - dimension.
The multi-channel photodiode 6 formed as shown in FIG.
5E. For reasons of manufacturing the multi-channel photodiode (6σ), it was necessary to provide a certain area on the semiconductor layer 2 from the cut edges thereof as a non-sensitive area. Further, in the multi-channel photodiode 6, the light receiving elements 3A to 3B are formed so that the spacing between the beak and each light receiving element 6A%E is equal, and the scintillation elements 5A to 5E are arranged in the same manner. It has a rectangular parallelepiped shape and is connected to the light receiving elements 67 to 6E in the photodiode 6 with the same pitch.
Each surface of the light-receiving element 5 other than the bonding surface with the light-receiving element 5E is coated with a reflective material 6 to prevent crosstalk.

However, in the X-ray detector 1 having the above configuration, among the scintillator elements 5A to 5EO arranged in the − dimension, the scintillator elements 5A and 5E located at both ends completely guide the emitted fluorescence to the light receiving elements 3A and 5E. Since it cannot move, the same X1 is applied to each scintillator element 5A-5E! Despite the incident amount, the light receiving elements 5A located at both ends,
Light receiving element 3B-3 where the output signal from 5E is located inside
Since the output signal is smaller than the output signal from D, there is a drawback that the detection accuracy of the multi-channel photodiode is reduced.

In order to eliminate the above-mentioned drawbacks, as shown in FIG. 2, in order to make the light-receiving surfaces n of each of the light-receiving elements 6A to 6E formed on the semiconductor layer 2 the same, and to secure a sufficient dead area,
Light receiving elements 5A located at both ends.

A roadway 2A between the edge of the light-receiving surface of 6E and the edge of the semiconductor layer 2.

A x7 detector 1 using a multi-channel photodiode 3 in which 2B is larger than the distance between the light-receiving surfaces of each of the light-receiving elements 5A to 5E has also been proposed.

However, the X-ray detector 1 shown in FIG. 2 has scintillator elements 5, located at both ends of the top.

5E is a light-receiving element located at both ends of the light emitting source! ? A, 6E, so if a plurality of X-ray detectors 1 are arranged in one dimension, the scintillator element located at the end of the xm detector 1 and the adjacent X-ray detector 61
The distance between the scintillator elements located at the ends of the X-ray detector 1 becomes larger than the mutual distance between the scintillator elements located inside the
Another drawback is that the pitch of the scintillator elements throughout the X-ray detector is no longer equal, reducing the detection accuracy of the X-ray detector as a whole.

In addition, in FIG. 1 and FIG. 2, the arrow X is X? PM
Indicates the direction of travel.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a radiation detector in which the detection accuracy of the multi-channel photodiode does not deteriorate, and the detection accuracy of the radiation detector as a whole does not deteriorate. This is the purpose.

[Summary of the invention]

The outline of the present invention for achieving the above object is that each scintillator element whose Ha emitting surface is stiff and has the same shape, and each light receiving element arranged and formed in the longitudinal direction on a semiconductor layer, In a radiation detector made by bonding so that each radiation incident surface of the scintillator element is arranged one-dimensionally at the same pitch, the light receiving surfaces of the light receiving elements located at both ends in the longitudinal direction are aligned with the light receiving surfaces of the light receiving elements located inside from both ends. It is characterized in that it is formed smaller than the light-receiving surface of the element, and the light output surfaces of the scintillator elements located at both ends are formed in the same shape as the light-receiving surfaces of the light-receiving elements located at both ends.

[Embodiments of the invention]

FIG. 6 is a schematic sectional view showing an embodiment of the present invention.

As shown in FIG. 6, a radiation detector, for example, an X-ray detector 1, which is an embodiment of the present invention, differs from the X-ray detector 1 shown in FIG. scintillator elements 5A to 5J (of which /ζ, 1II
The shapes of the light output surfaces (bottom surfaces) of the scintillator elements 5A and 5E located at the ends of the light receiving elements 3. (,3E
The scintillator elements 5A and 5E are cut out from the side surface to the bottom surface so that the light receiving surface is the same as the light receiving surface. Of course, the scintillator elements 5A and 5 at both ends
All surfaces other than the light output surface of E are coated with an original reflective material 6, and scintillator elements 5A and 5EO) are coated with the light output surface and the light receiving elements A located at both ends.
The light-receiving surface of E is bonded with a strange adhesive, even an adhesive for Lt glass.

In addition, in Figure 5 I, the parts indicated by the same numbers as in Figures 1 and 2 are the same parts as in Figures 1 and 2. Since the X-ray detector 1 is configured as follows.

Even if XH of the same XHJit is incident, the fluorescence emitted by each scintillator element 5A to 5E, especially the scintillator elements 5A and 5E located at both ends, is completely transferred to the light receiving surface of the light receiving element sA, sp: located at both ends. Therefore, a decrease in detection accuracy of the X-ray detector 1 can be prevented. Moreover, the scintillator elements 5A located on both sides,
Since the area of the light output surface of 5E is made small, the light receiving surfaces of light receiving elements 3A and 6EcD located at both ends can be kept small accordingly.

As shown in the X-ray detector 1 shown in Fig. 2, it is not necessary to increase the longitudinal length of the semi-integrated body layer 2, so the plurality of X-ray detectors 1 shown in Fig. 6 can be arranged in one dimension. Even if they are arranged, the X-ray incident surfaces of the respective scintillator elements can be arranged at the same pitch, and it is possible to prevent deterioration of the detection accuracy of the entire X-ray detector.

Although one embodiment of the present invention has been described above in detail, the present invention is not limited to the embodiment described above, and can be implemented with appropriate modifications within the scope of the gist of the invention.

For example, scintillator elements 5A (5E
) is not limited to the shape of the above embodiment, but may be a hexahedron with a trapezoidal cross section in the longitudinal direction as shown in FIG. A pig-curved surface may be formed between the surface and the longitudinal side surface adjacent to the surface.

〔Effect of the invention〕

According to this invention, even if the light-receiving surfaces of the light-receiving elements located at both ends of the longitudinal arrangement are smaller than the light-receiving surfaces of the light-receiving elements located inside, the detection accuracy of the radiation detector is prevented from deteriorating. be able to. Moreover, the scintillator elements with the same radiation incident surface are arranged at the same pitch, and the semiconductor layer is not unnecessarily long in the longitudinal direction, so the radiation detector is made by arranging the radiation detectors in one dimension. As a whole, scintillator elements can be arranged one-dimensionally at the same pitch, and a decrease in detection accuracy as a whole can be prevented.

[Brief Description of the Drawings] Figures 1 and 2 are cross-sectional views showing a conventional radiation detector, Figure 6 is a cross-sectional view showing an embodiment of the present invention, and Figures 4 and 5 are cross-sectional views of a conventional radiation detector. Other embodiments of the invention (this is a schematic perspective view showing a scintillator element used here) 6 1... Radiation detector, 2... Semiconductor layer, 6
...Multi-channel photodiode arrays
3A to 3E... Light receiving element, 4. Adhesive s 57
~5E river scintillator element, 6... Original reflective material. Agent Patent Attorney Noriyuki Chika (and 1 other person) XXXX 1 11 (xxx 51]'/'('5. Ru 4 Country, 5A (5E); "Condolence 5 Diagram

Claims (1)

[Claims] Each scintillator element whose radiation entrance surface has the same shape and each light receiving element arranged and formed in the longitudinal direction on one layer of semiconductor are arranged one-dimensionally with each radiation entrance surface of each scintillator element at the same pitch. As shown in FIG. A radiation detector characterized in that the light output surface of the scintillator element is formed in the same shape as the light receiving surfaces of the light receiving elements located at both ends.