JPH05180947A - Radiation detector - Google Patents

Abstract

PURPOSE:To obtain a radiation detector which can obtains the internal information of a sample in two dimensions. CONSTITUTION:Photoelectric conversion parts 11 are partitioned in two dimensions by providing vertical and lateral partitioning walls 12a and 12b. Therefore, the information of the incident radiation into positions (a) is independently detected with each partitioned photoelectric conversion element 11a located at the lower side of the position (a). The information of the incident radiation into a position (b) is detected with each partitioned photoelectric conversion element 11b located at the lower part. Therefore, the two-dimensional detection can be performed. As the light emitting means, the sintered scintillator material, which is indicated by Gd2O2S:Pr, or Gd2O2S:Pr, Ce, F is preferable from the viewpoints of light emitting property and sensitivity. As the photoelectric conversion means, well-known silicon photodiodes can be used. The amorphous photoelectric conversion means such as the amorphous silicon photodiodes are desirable from the viewpoint of improvement in resolution because the light emitting means can be made thin since the deterioration caused by the X-ray emission is less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation detector for performing a nondestructive inspection or a living body inspection using radiation such as X-rays, α-rays, γ-rays, etc., which have high penetrating ability to a substance, The present invention relates to a radiation detector provided with a photodiameter as photoelectric conversion means for taking out radiation such as transmitted X-rays as electrical two-dimensional information.

[0002]

2. Description of the Related Art Radiation detectors using radiation such as X-rays, α-rays and γ-rays have been used for nondestructive inspection of materials and fluoroscopic inspection of human bodies. As shown in FIG. 2, this radiation detector comprises a scintillator layer 4 in which a plurality of scintillator elements 3 as light emitting means are laminated via a partition wall 2 on a silicon photo diode 1 as photoelectric conversion means, and X The X-ray beam 6 emitted from the radiation source 5 passes through the subject 7 and then enters the scintillator element 3, and the light generated inside the scintillator element 3 induced by the X-rays is photoelectrically converted in the silicon photodivisor 1. Has been
It is output as electrical information.

[0003]

Regarding the above radiation detector, the applicant of the present invention, in Japanese Patent Application No. 3-27900, which is a prior application, provided the same on a silicon photodiameter 1 as photoelectric conversion means as shown in the figure. The scintillator layer 4 to be formed is formed by a plurality of scintillator elements 3 divided by the partition walls 2 formed in columns to prevent the diffusion of light generated in the scintillator layer 4 and make the obtained image clearer. I suggested that.

[0004] However, Japanese Patent Application No. 3-2790 relating to this applicant's application
The radiation detector shown in No. 0 had room for further improvement as follows.

[0005] That is, in the radiation detector shown in Japanese Patent Application No. 3-27900, each scintillator element 3 divided by the partition wall 2 is
It was not possible to discriminate the information incident on the A position and the information incident on the B position on the scintillator element 3 by catching the light irradiated on the surface as only one unit information amount. In other words, from the viewpoint of the possibility of multidimensional information detection, in the radiation detector shown in Japanese Patent Application No. 3-27900, the information detection inside the subject 7 is one-dimensional and two-dimensional. There was a problem that it could not be detected. This point will be further described in detail with reference to FIG. When the subject (7) containing foreign matter is uniformly irradiated with X-rays in the direction of the arrow, the intensity distribution of the transmitted X-ray clearly captures the foreign matter as shown by the curve (10).
This transmitted X-ray irradiates the scintillator element 3, and this irradiation causes the scintillator element 3 to emit light. The emitted light is silicon photo diode
Although it reaches 1, the current output distribution of the silicon photodiode 1 obtained by this light becomes a curve 11. The information obtained from the curve 11 is the subject 7 corresponding to any area divided by the partition wall 2 specified by the position of the peak of the curve 11.
It is the presence or absence of the contaminants 8 in the above certain area, and as far as that is the information obtained by the conventional radiation detector is one-dimensional information indicating the presence or absence of the impurities 8 on the line along the certain direction of the subject 7. It was

[0006] Therefore, the present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a radiation detector capable of two-dimensionally capturing internal information of a sample. To do.

[0007]

According to the present invention, in a radiation detector comprising a photoelectric conversion means and a light emitting means, the photoelectric conversion means is divided into two or more directions, and the light emitting means is provided on the photoelectric conversion means. By doing so, the above object was achieved.

The present invention will be described below with reference to FIG. FIG. 1 is a perspective view showing a radiation detector according to the present invention. This detector has a vertical partition wall 12a and a horizontal partition wall 12b.
It has a structure in which a light emitting means 13 is fixed on a photoelectric conversion section 11 which is divided in a dimension.

In the present invention, the photoelectric conversion unit 11 has vertical and horizontal partitions 12a and 12b.
It has a feature in that it is divided into two dimensions by providing. That is, since the photoelectric conversion unit 11 is two-dimensionally divided, the information of the radiation incident on the position a is the divided photoelectric conversion element 11a located below it, and the information of the radiation incident on the position b is below it. Since the divided photoelectric conversion elements 11b located at are individually detected, two-dimensional detection is possible.

[0010] As a typical example of dividing the photoelectric conversion means into at least two directions or more, an example in which partition walls 12a and 12b orthogonal to each other are provided is shown in FIG. 1, but the present invention is not limited to this, and the photoelectric conversion means may be vertically or vertically arranged. It is sufficient if the photoelectric conversion elements are divided in the lateral direction and each of the divided photoelectric conversion elements independently exhibits a photoelectric conversion function.

[0011] In the radiation detector of the present invention, a conventionally known scintillator material can be used as the light emitting means. Gd ₂ O ₂ S: Pr or Gd ₂ O ₂ S: Pr, C
Sintered scintillator materials represented by e and F are preferable.

[0012] As the photoelectric conversion means, a known silicon photodiode can be used. In particular, amorphous photoelectric conversion means such as amorphous silicon photodiode is less deteriorated by X-ray irradiation, so that the light emitting means can be made thinner, which is desirable from the viewpoint of improving resolution.

Further, in the present invention, the light emitting means made of a scintillator material may be provided with the same partition wall as the photoelectric conversion means for division.

[0014]

Embodiments of the present invention will be described below. Figure
1 schematically shows one embodiment of the radiation detector of the present invention. As shown, not only the vertical direction of the partition wall 12a only on the amorphous silicon photo data Bu Ioto Bu 11, transverse partition wall 12b is formed, Gd ₂ 0 ₂ S thereon: Pr based light emitting material or Gd ₂ 0 ₂ S: P
A scintillator layer 13 made of an r, Ce, F-based light emitting material is formed.

Example 1 Gd ₂ 0 ₂ S: Pr, Ce, F having a thickness of 100 μm was formed on a crystalline silicon photo diode in which parallel partitions having a spacing of 100 μm were provided in two directions in the vertical and horizontal directions.
Mount a scintillator sintered body, manufacture a radiation detector,
A resolution of 5 lines / mm was obtained.

Example 2 Gd ₂ 0 ₂ S: Pr, Ce, F having a thickness of 100 μm was formed on an amorphous silicon photo-diode in which parallel partitions having a spacing of 100 μm were provided in two vertical and horizontal directions.
Mount a scintillator sintered body, manufacture a radiation detector,
A resolution of 4 lines / mm was obtained.

[0017]

As described above, according to the radiation detector of the present invention, the photoelectric conversion means is divided into two or more directions, and the scintillator layer is provided on the photoelectric conversion means. It is possible.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a radiation detector portion of an embodiment of the present invention.

FIG. 2 is a schematic diagram of a conventional radiation detector.

FIG. 3 is a diagram showing an image obtained by a radiation detector in comparison with a conventional one and the present invention. 11 Amorphous silicon photodiameter 12a Partition 12b Partition 13 Scintillator layer

Claims (4)

[Claims] 1. A radiation detector comprising photoelectric conversion means and light emitting means, wherein the photoelectric conversion means is divided into two or more directions, and the light emitting means is provided on the photoelectric conversion means divided into two or more directions. A radiation detector characterized by being provided. 2. The radiation detector according to claim 1, wherein the photoelectric conversion means is an amorphous silicon photo diode. 3. The radiation detector according to claim 1, wherein the photoelectric conversion means is a Gd ₂ O ₂ S: Pr-based sintered body. Wherein said scintillator _{Gd 2 0 2 S: Pr,} Ce, a radiation detector according to claim 1, 2 or 3 is F sintered body.