Dosimeter

Patent metadata

Field	Value
Publication number	US-11914083-B2
Application number	US-202017639465-A
Country	US
Kind code	B2
Filing date	Sep 1, 2020
Priority date	Sep 2, 2019
Publication date	Feb 27, 2024
Grant date	Feb 27, 2024

Abstract

This dosimeter comprises:a transducer material capable, when it is excited by a secondary ionizing radiation, of generating photons or electric charges,an amplifying layer capable, in response to its excitation by the primary ionizing radiation, of generating the secondary ionizing radiation.This amplifying layer comprises a first and a second amplifying sublayer stacked on top of one another. The first and the second amplifying sublayers are composed of at least 70%, by weight, respectively, of at least one first and one second material, the atomic numbers of which are greater than or equal to 29. The atomic number of the first material being less than the atomic number of the second material. The first sublayer is interposed between the second sublayer and the transducer material.

First claim

The invention claimed is:

1. A dosimeter for measuring the intensity of a primary ionizing radiation, the dosimeter comprising:
a transducer material capable, when it is excited by a secondary ionizing radiation, of generating photons or electric charges, the number of photons or of charges generated being representative of the intensity of the primary ionizing radiation,
an amplifying layer capable, in response to its excitation by the primary ionizing radiation, of generating the secondary ionizing radiation which excites the transducer material, this amplifying layer:
being deposited on the transducer material, and
being composed of at least 70%, by weight, of material, the atomic number of which is greater than or equal to 29, and

an optical fiber comprising a core capable of guiding light,

wherein:
the thickness of this amplifying layer is greater than 15 μm,
the amplifying layer comprises at least one first and one second amplifying sublayer stacked on top of one another,
the first and the second amplifying sublayers are composed of at least 70%, by weight, respectively, of at least one first and one second material, the atomic numbers of which are greater than or equal to 29, the atomic number of the first material being less than the atomic number of the second material,
the first amplifying sublayer is interposed between the second amplifying sublayer and the transducer material, and
the transducer material is a luminescent material capable, when it is excited by the secondary ionizing radiation, of generating the light guided by the core of the optical fiber.

2. The dosimeter as claimed in claim 1 , wherein the dosimeter further comprises a reflective layer interposed between the luminescent material and the amplifying layer, this reflective layer:
covering the luminescent material,
being made of a material, the atomic number of which is less than the atomic number of the material used to produce the amplifying layer,
being capable of reflecting the light generated by the luminescent material toward the core of the optical fiber, and
being transparent to the secondary ionizing radiation.

3. The dosimeter as claimed in claim 2 , wherein the reflective layer is made of aluminum and its maximum thickness is less than 300 nm.

4. The dosimeter as claimed in claim 1 , wherein the thickness of the amplifying layer is less than 100 μm or 50 μm.

5. The dosimeter as claimed in claim 1 , wherein the second amplifying sublayer is made of gold or lead or an alloy composed of more than 90%, by weight, of gold and lead.

6. The dosimeter as claimed in claim 1 , wherein the optical fiber has a light input face inside the core of this optical fiber, and the luminescent material covers at least a part of the light input face.

7. The dosimeter as claimed in claim 6 , wherein the luminescent material covers all of the light input face.

8. The dosimeter as claimed in claim 7 , wherein the light input face extends, in a direction parallel to an axis of the optical fiber, over a distance greater than 20 μm or 100 μm.

9. The dosimeter as claimed in claim 6 , wherein the light input face is preformed in such a way that more than 50% of the photons generated by the luminescent material penetrate into the core of the optical fiber.

10. The dosimeter as claimed in claim 9 , wherein the light input face comprises a conical or frustoconical face having at least four symmetries of revolution about an axis of the optical fiber and situated in an extension of the core of the optical fiber.

11. The dosimeter as claimed in claim 6 , wherein the luminescent material has more than ten symmetries of revolution about an axis of the optical fiber.

12. The dosimeter as claimed in claim 6 , wherein an outer diameter of the optical fiber is less than 500 μm.

13. The dosimeter as claimed in claim 6 , wherein the dosimeter further comprises an optical amplifier connected to an end of the optical fiber and capable of amplifying the light generated by the luminescent material.

14. The dosimeter as claimed in claim 1 , wherein the first amplifying sublayer is made of gold, of silver, or of copper and has a thickness greater than 15 μm.

15. The dosimeter as claimed in claim 14 , wherein the second amplifying sublayer is made of lead or of an alloy composed of more than 90%, by weight, of gold and lead.

Assignees

• Centre Nat Rech Scient
• Univ Aix Marseille
• Inst Jean Paoli & Irene Calmettes Centre Regional De Lutte Contre Le Cancer

Inventors

• Debnath Sree Bash Chandra
• Darreon Julien
• Fauquet Carole
• Tonneau Didier
• Tallet Agnès

Classifications

• G01T1/10 Primary

  Luminescent dosimeters · CPC title

• G01T1/023 Primary

  Scintillation dose-rate meters · CPC title

• G01T1/026

  Semiconductor dose-rate meters · CPC title

• G01T1/20

  with scintillation detectors · CPC title

• G01T1/2002

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