Radiation detector and radiation detection device

Patent metadata

Field	Value
Publication number	US-12153172-B2
Application number	US-202217747107-A
Country	US
Kind code	B2
Filing date	May 18, 2022
Priority date	May 31, 2021
Publication date	Nov 26, 2024
Grant date	Nov 26, 2024

Abstract

A radiation detector of one embodiment includes: a scintillator configured to generate first scintillation light having a first peak wavelength and second scintillation light having a second peak wavelength in response to radiation incidence; a photodetection unit configured to detect the scintillation light generated by the scintillator; and a filter layer disposed between the scintillator and the photodetection unit and configured to selectively block the first scintillation light. The filter layer has a metasurface structure.

First claim

What is claimed is:

1. A radiation detector comprising:
a scintillator configured to generate first scintillation light having a first peak wavelength and second scintillation light having a second peak wavelength in response to radiation incidence;
a photodetection unit configured to detect the scintillation light generated by the scintillator;
a filter layer disposed between the scintillator and the photodetection unit and configured to selectively block the first scintillation light; and
a second photodetection unit disposed on a side opposite to a side where the filter layer is provided with respect to the scintillator,
wherein the filter layer has a metasurface structure,
wherein the filter layer has a plurality of columnar metal structures arranged periodically,
wherein both the first peak wavelength and the second peak wavelength are in a wavelength region of less than 350 nm, and
wherein a period, a height, and a width of the plurality of columnar metal structures of the filter layer are set such that a reflectance for the first peak wavelength is at least 2.5 times a reflectance for the second peak wavelength.

2. The radiation detector according to claim 1 ,
wherein the filter layer is a plasmonic filter using a surface plasmon.

3. The radiation detector according to claim 1 ,
wherein the metal structure is configured by cylindrical aluminum.

4. The radiation detector according to claim 1 ,
wherein the first scintillation light is longer in decay time than the second scintillation light.

5. The radiation detector according to claim 1 ,
wherein the scintillator has a first surface facing the photodetection unit and a second surface not facing the photodetection unit, and
wherein at least a part of the second surface is provided with a light absorption layer configured to absorb the first scintillation light reflected by the filter layer.

6. The radiation detector according to claim 1 ,
further comprising a second filter layer disposed between the scintillator and the second photodetection unit and configured to selectively block the second scintillation light.

7. The radiation detector according to claim 6 ,
wherein the second filter layer has a metasurface structure.

8. The radiation detector according to claim 7 ,
wherein the second filter layer is configured by a plurality of holes corresponding to the plurality of columnar metal structures of the filter layer.

9. The radiation detector according to claim 1 ,
wherein the photodetection unit is a solid-state image sensor or an electron tube.

10. The radiation detector according to claim 1 ,
wherein the radiation detector is an electron tube,
wherein the scintillator is a light incident window of the electron tube, and
wherein the photodetection unit is a photoelectric surface of the electron tube.

11. The radiation detector according to claim 10 ,
further comprising a protective film provided between the filter layer and the photodetection unit.

12. A radiation detection device comprising a gantry where a plurality of the radiation detectors according to claim 1 are arranged.

Assignees

• Hamamatsu Photonics Kk

Inventors

• Ota Ryosuke
• UENOYAMA Soh

Classifications

• G01T1/2018

  Scintillation-photodiode combinations · CPC title

• G01T1/20188

  Auxiliary details, e.g. casings or cooling · CPC title

• G01T7/00

  Details of radiation-measuring instruments · CPC title

• G01T1/2002 Primary

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

• G01T1/20185 Primary

  Coupling means between the photodiode and the scintillator, e.g. optical couplings using adhesives with wavelength-shifting fibres · CPC title