Apparatus for detecting radiation and method of providing an apparatus for detecting radiation

Patent metadata

Field	Value
Publication number	US-10459090-B2
Application number	US-201615757487-A
Country	US
Kind code	B2
Filing date	Aug 31, 2016
Priority date	Sep 9, 2015
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

An apparatus and method, the apparatus comprising: a plurality of layers of scintillator material configured to generate photons in response to incident radiation; and a plurality of layers of spacer material wherein the scintillator material and spacer material are arranged in alternate layers so that a plurality of interfaces are provided between layers of scintillator material and layers of spacer material; wherein the scintillator material has a different refractive index to the spacer material and the thickness of layers within the plurality of layers is arranged to enable constructive interference of photons emitted by the scintillator material and reflected by the interfaces.

First claim

We claim:

1. An apparatus comprising:
a plurality of layers of scintillator material configured to generate photons in response to incident X-ray radiation; and
a plurality of layers of spacer material wherein the scintillator material and spacer material are arranged in alternate layers so that a plurality of interfaces are provided between layers of scintillator material and layers of spacer material;
wherein the scintillator material has a different refractive index to the spacer material and the thickness of layers within the plurality of layers of scintillator material and the plurality of layers of spacer material is arranged to enable constructive interference of photons emitted by the scintillator material and reflected by the interfaces.

2. An apparatus as claimed in claim 1 wherein the constructive interference is configured to collimate photons emitted by the scintillator material towards a direction perpendicular to the plurality of layers of scintillator material and plurality of layers of spacer material.

3. An apparatus as claimed in claim 1 wherein the plurality of layers of scintillator material and plurality of layers of spacer material are arranged to form a distributed Bragg reflector.

4. An apparatus as claimed in claim 1 wherein the plurality of layers of scintillator material and plurality of layers of spacer material are configured so that photons emitted by the scintillator material are arranged to be focused on a pixel of a photodetector.

5. An apparatus as claimed in claim 1 wherein the scintillator material has a higher refractive index than the spacer material.

6. An apparatus as claimed in claim 1 wherein the spacer material comprises a second type of scintillator different to a first type of scintillator within the scintillator material.

7. An apparatus as claimed in claim 1 wherein the thickness t of the layers within the plurality of layers of scintillator material and plurality of layers of spacer material is given by t=xλ/n, where x is a fraction of wavelength of the photon, λ is the free-space wavelength of the photon and n is the refractive index of the layer.

8. An apparatus as claimed in claim 1 comprising a reflective layer.

9. An apparatus as claimed in claim 1 comprising a photodetector.

10. An apparatus as claimed in claim 1 wherein the scintillator material comprises microstructured crystal scintillators.

11. An apparatus as claimed in claim 1 wherein the scintillator material is arranged in columnar structures.

12. A radiation detector comprising:
a plurality of layers of scintillator material configured to generate photons in response to incident X-ray radiation; and
a plurality of layers of spacer material wherein the scintillator material and spacer material are arranged in alternate layers so that a plurality of interfaces are provided between layers of scintillator material and layers of spacer material;
wherein the scintillator material has a different refractive index to the spacer material and the thickness of layers within the plurality of layers is arranged to enable constructive interference of photons emitted by the scintillator material and reflected by the interfaces.

13. A method comprising:
providing a plurality of layers of scintillator material configured to generate photons in response to incident X-ray radiation; and
providing a plurality of layers of spacer material wherein the scintillator material and spacer material are arranged in alternate layers so that a plurality of interfaces are provided between layers of scintillator material and layers of spacer material;
wherein the scintillator material has a different refractive index to the spacer material and the thickness of layers within the plurality of layers is arranged to enable constructive interference of photons emitted by the scintillator material and reflected by the interfaces.

14. A method as claimed in claim 13 wherein the constructive interference is configured to collimate photons emitted by the scintillator material towards a direction perpendicular to the plurality of layers of scintillator material and plurality of layers of spacer material.

15. A method as claimed in claim 13 wherein the plurality of layers of scintillator material and plurality of layers of spacer material are arranged to form a distributed Bragg reflector.

16. A method as claimed in claim 13 wherein the plurality of layers of scintillator material and plurality of layers of spacer material are configured so that photons emitted by the scintillator material are arranged to be focused on a pixel of a photodetector.

17. A method as claimed in claim 13 wherein the scintillator material has a higher refractive index than the spacer material.

18. A method as claimed in claim 13 wherein the spacer material comprises a second type of scintillator different to a first type of scintillator within the scintillator material.

19. A method as claimed in claim 13 wherein the thickness t of the individual layers within the plurality of layers of scintillator material and plurality of layers of spacer material is given by t=xλ/n, where x is a fraction of wavelength of the photon, λ is the free-space wavelength of the photon and n is the refractive index of the layer.

20. A method as claimed in claim 13 wherein the plurality of layers of scintillator material and the plurality of layers of spacer material are arranged to form a lamina structure, and providing a reflective layer on a first side of the lamina structure.

21. The method of claim 1 , wherein the alternate layers of the scintillator material and the spacer material are arranged in a direction perpendicular to a direction associated with the incident X-ray radiation.

22. The radiation detector of claim 12 , wherein the alternate layers of the scintillator material and the spacer material are arranged in a direction perpendicular to a direction associated with the incident X-ray radiation.

23. The method of claim 13 , wherein the alternate layers of the scintillator material and the spacer material are arranged in a direction perpendicular to a direction associated with the incident X-ray radiation.

Assignees

• Nokia Technologies Oy

Inventors

• Radivojevic Zoran
• Astley Michael
• Andrew Piers

Classifications

• G01T1/2002 Primary

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

• G01T1/2018

  Scintillation-photodiode combinations · CPC title