Radiation detector, and radiation tomography device provided with same

Patent metadata

Field	Value
Publication number	US-10267926-B2
Application number	US-201615573471-A
Country	US
Kind code	B2
Filing date	Mar 18, 2016
Priority date	May 12, 2015
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

Provided is a radiation detector 1 which is high in radiation detection sensitivity and is capable of preventing a loss of fluorescence by integrating scintillator crystals C and reflection plates rx and ry without using a permeable material. According to the present invention, the adhesive sheets Sa and Sb are adhered to the ends of scintillator crystals C arranged in a matrix in the height direction. The scintillator crystals C are integrated by the adhesive sheets Sa and Sb. According to the present invention, there is no need to form a scintillator 2 by securing the scintillator crystals C and the reflection plates ry by an adhesive. Therefore, an adhesive before curing does not enter gaps between the scintillator crystal C and the reflection plate ry, and therefore the gap forms an air layer. With such a configuration, a phenomenon that the fluorescence generated inside the scintillator crystal C is emitted out of the scintillator crystal C becomes less likely occur, which in turn can minimize a decrease in the intensity of fluorescence.

First claim

The invention claimed is:

1. A radiation detector comprising:
scintillator crystals that convert radiation into fluorescence;
reflection plates that reflect the fluorescence, the reflection plate being provided in a gap between the scintillator crystals arranged in a matrix;
an air layer provided at a position sandwiched by the reflection plate and the scintillator crystal;
a first adhesive sheet adhered to a first end of each of the scintillator crystals in a height direction; and
a second adhesive sheet adhered to a second end of each of the scintillator crystals in the height direction, the second end being opposite to the first end,
a light detector that detects the fluorescence is optically coupled to a surface of the first adhesive sheet opposite to a surface to which the scintillator crystals are adhered,
wherein a scintillator is formed by integrating the scintillator crystals with the first adhesive sheet.

2. The radiation detector as recited in claim 1 ,
wherein the first adhesive sheet is a transparent sheet that allows fluorescence to pass through, and
wherein a light detector that detects the fluorescence or a light guide that guides the fluorescence generated by the scintillator to the light detector is optically coupled to a surface of the first adhesive sheet opposite to a surface to which the scintillator crystals are adhered.

3. The radiation detector as recited in claim 2 ,
wherein the surface of the first adhesive sheet opposite to a surface to which the scintillator crystals are adhered has adhesiveness, and the first adhesive sheet is adhered to the light detector.

4. The radiation detector as recited in claim 3 ,
wherein the light detector is composed of a photomultiplier tube which is a vacuum tube, and
wherein the first adhesive sheet is adhered to the light detector in a state in which the first adhesive sheet is deformed in accordance with a distortion of a light receiving surface of the light detector to which the fluorescence is incident.

5. The radiation detector as recited in claim 2 ,
wherein the surface of the first adhesive sheet opposite to a surface to which the scintillator crystals are adhered does not have adhesiveness, and the scintillator is optically coupled to the light detector by a connection material.

6. The radiation detector as recited in claim 2 ,
wherein the light detector includes a semiconductor light receiving element.

7. The radiation detector as recited in claim 1 ,
wherein the first adhesive sheet is an acrylic adhesive sheet.

8. A radiation tomography apparatus equipped with the radiation detector as recited in claim 1 .

9. The radiation detector of claim 1 ,
wherein a first set of the reflection plates extend in a first direction between first two or more pairs of adjacent scintillator crystals,
wherein a second set of the reflection plates extend in a second direction between second two or more pairs of adjacent scintillator crystals, the first and second directions being perpendicular to the height direction, and
wherein the first and second sets of the reflection plates have a same height.

10. The radiation detector of claim 1 ,
wherein with respect to a cross-section, side surfaces of the reflection plates are parallel with side surfaces of the scintillator crystals.

11. A radiation detector comprising:
scintillator crystals that convert radiation into fluorescence;
reflection plates that reflect the fluorescence, the reflection plate being provided in a gap between the scintillator crystals arranged in a matrix;
an air layer provided at a position sandwiched by the reflection plate and the scintillator crystal; and
a first adhesive sheet adhered to a first end of each of the scintillator crystals in a height direction,
a second adhesive sheet adhered to a second end of each of the scintillator crystals in the height direction, the second end being opposite to the first end,
wherein a scintillator is formed by integrating the scintillator crystals with the first adhesive sheet, and
wherein the first adhesive sheet absorbs a difference between a three-dimensional shape of a lower side of an array of the scintillator crystals and a three-dimensional shape of an incident surface of a light detector and integrates the array of the scintillator crystals and the light detector.

12. The radiation detector of claim 11 ,
wherein a first set of the reflection plates extend in a first direction between first two or more pairs of adjacent scintillator crystals, and
wherein a second set of the reflection plates extend in a second direction between second two or more pairs of adjacent scintillator crystals, the first and second directions being perpendicular to the height direction.

13. The radiation detector of claim 12 ,
wherein the first and second sets of the reflection plates have a same height.

14. The radiation detector of claim 12 ,
wherein each reflection plate of the first set of the reflection plates has first grooves extending from a top portion of the reflection plate,
wherein each reflection plate of the second set of the reflection plates has second grooves extending from a bottom portion of the reflection plate,
wherein the first set of the reflection plates and the second set of the reflection plates form a reflection plate frame by fitting the first grooves of the first set of the reflection plates with the second grooves of the second set of the reflection plates, and
wherein each reflection plate of the first and second sets of reflection plates has the same height and the same thickness and is made of the same material.

15. The radiation detector of claim 11 ,
wherein each scintillator crystal is separated from an adjacent scintillator crystal by a reflection plate, and
wherein each reflection plate extends from a first end of the scintillator crystals to a second end of the scintillator crystals, the second end being opposite to the first end in the height direction.

16. The radiation detector of claim 15 ,
wherein with respect to a cross-section, side surfaces of the reflection plates are parallel with side surfaces of the scintillator crystals.

17. The radiation detector of claim 11 , wherein each of the reflection plates have the same height and the same thickness and are made of the same material.

Assignees

• Shimadzu Corp

Inventors

• Tonami Hiromichi
• Tsuda Tomoaki

Classifications

• G01T1/202

  the detector being a crystal · CPC title

• G01T1/2002 Primary

  Optical details, e.g. reflecting or diffusing layers · CPC title

• G01T1/2006

  using a combination of a scintillator and photodetector which measures the means radiation intensity · CPC title

• G01T1/1603

  with a combination of at least two different types of detectors · CPC title