Inorganic Scintillating Mixture and a Sensor Assembly For Charged Particle Dosimetry

• US 20080164416A1
• Filed: 08/21/2004
• Published: 07/10/2008
• Est. Priority Date: 12/04/2003
• Status: Abandoned Application

• Current Assignee: Paul Scherrer-Institut (Schweizerische Eidgenossenschaft)
• Original Assignee: Paul Scherrer-Institut (Schweizerische Eidgenossenschaft)
• Inventors: Safai, Sairos
• Application Number:
  US10/581,405
• Publication Number:
  US 20080164416A1
• Time in Patent Office: Days
• US Class Current: 250/366
• CPC Class Codes: G01T 1/023 Scintillation dose-rate meters
• CPC Class Codes: G01T 1/202 the detector being a crystal
• CPC Class Codes: G01T 1/2023 Selection of materials see provisionally also G01T1/202

Abstract

An inorganic scintillating mixture includes at least a first and a second component, each having a characteristic behavior in response to the irradiation with charged particles, such as protons and heavy ions, showing a typical Bragg peak with respect to a relative depth dose. The first component has a quenching characteristic in the Bragg peak region and the second component shows an increased efficiency in the Bragg peak region both related to a reference curve for the relative dose.

Claims

1. An inorganic scintillating mixture comprising at least a first and a second component each having a characteristic behavior in response to an irradiation with charged particles, showing a typical Bragg peak with respect to a relative depth dose;

said first component having a quenching characteristic in a Bragg peak region and said second component showing an increased efficiency in the Bragg peak region, both being related to a reference curve for a relative dose.

2. The inorganic scintillating mixture according to claim 1, comprising as the first component Gadolinium-Oxy-Sulfid (Gd₂O₂S:

Tb) and as the second component Zinc-Cadmium-Sulfid (Zn,Cd)S;

Ag.

3. The inorganic scintillating mixture according to claim 2, wherein a content of Gd₂O₂S:

Tb is in a range of 60 to 90% wt and a content of (Zn,Cd)S;

Ag is in a range of 10 to 40% wt.

4. The inorganic scintillating mixture according to claim 3, wherein the content of Gd₂O₂S:

Tb is in the range of 75 to 85% wt and the content of (Zn,Cd)S;

Ag is in the range of 15 to 25% wt.

5. An inorganic scintillating mixture comprising at least a first, a second and a third component, wherein the first and the second components have a characteristic behavior in response to an irradiation with charged particles showing a typical Bragg peak with respect to a relative depth dose;

said first component having a quenching characteristic in a Bragg peak region and said second component showing an increased efficiency in the Bragg peak region in comparison to a reference curve for a relative dose and said third component having a binder characteristic in order to hold the first and the second component in a desired mechanical shape.

6. The inorganic scintillating mixture according to claim 5, comprising as the first component Gadolinium-Oxy-Sulfid (Gd₂O₂S:

Tb), as the second component Zinc-Cadmium-Sulfid (Zn,Cd)S;

Ag, and as the third component an optical cement.

7. The inorganic scintillating mixture according to claim 6, wherein a content of the optical cement is in a range of 20 to 60% wt, a content of Gd₂O₂S:

Tb is in a range of 30 to 60% wt and a content of (Zn,Cd)S;

Ag is in a range of 05 to 30% wt.

8. The inorganic scintillating mixture according to claim 7, wherein the content of the optical cement is in the range of 35 to 45% wt, the content of Gd₂O₂S:

Tb is in the range of 43 to 53% wt and the content of (Zn,Cd)S;

Ag is in the range of 07 to 17% wt, preferably 40 resp. 48 resp. 12% wt.

9. A sensor assembly for charged particle dosimetry, comprising a three-dimensional array of sensor heads, each sensor head being located on one end of an optical fiber, an opposite end of the optical fiber being associated with an optical light intensity measuring assembly, each sensor head and at least partially the optical fiber are inserted into a respective cavity located in a holder member.

10. The sensor assembly according to claim 9, wherein the holder member is a substantially cylindrical shaped organic body;

said cavity is oriented along a longitudinal axis and has a depth aligned with a desired sensor head position in said three-dimensional array.

11. The sensor assembly according to claim 9, wherein the holder members are attached in a holder block generating a regular pattern of the sensor heads as seen in a direction parallel to a longitudinal axis of the holder members .

12. The sensor assembly according to claim 11, wherein the regular pattern is a hexagonal pattern allowing to accommodate a sensor heads relative to adjacent sensor heads in an equidistant manner.

13. The sensor assembly according to claim 11. wherein the holder block is related with a stopper member being disposed opposite to the holder block assuring that each tip of the holder member is oriented with a distinct distance from the holder block as seen along the longitudinal axis of the holder members.

14. The sensor assembly according to claim 9, wherein the holder member comprises an annular notch being associated with a sealing ring disposed in the holder block or on the notch.

15. The sensor assembly according to claim 9, wherein the sensor head has a cylindrical shape and comprises a mixture containing optical cement, Gd₂O₂S:

Tb and (Zn,Cd)S;

Ag.

16. The sensor assembly according to claim 15, wherein the sensor head has a diameter in a range of 1 to 5 mm and a height in a range of 1 to 5 mm.

17. The sensor assembly according to claim 15, wherein a surface of the sensor head opposite to a surface connected to the optical fiber is layered with a reflexion film.

18. The sensor assembly according to claim 9, wherein the three-dimensional array is disposed in a cuboid sensor volume in a manner that the sensor head positions are defined in a plane substantially parallel to a (111)-plane in a crystal having a cuboid pattern.

19. (canceled)

20. (canceled)

21. (canceled)