LuxY(1−x)Xa3 scintillators

• US 7,365,333 B1
• Filed: 05/25/2007
• Issued: 04/29/2008
• Est. Priority Date: 05/26/2006
• Status: Active Grant

• Current Assignee: Radiation Monitoring Devices, Inc. (Dynasil Corp. of America)
• Original Assignee: Radiation Monitoring Devices, Inc. (Dynasil Corp. of America)
• Inventors: Glodo, Jaroslaw, Higgins, William M., Shah, Kanai S., Van Loef, Edgar V
• Primary Examiner(s): Porta; David
• Assistant Examiner(s): Baker; David S
• Application Number:
  US11/754,200
• Time in Patent Office: 340 Days
• Field of Search: 250/301.4 R, 250/484.4, 250/484.2, 250/483.1, 250/361.R, 252/301.4 H
• US Class Current: 250/361.00R
• CPC Class Codes: G01T 1/2018 Scintillation-photodiode combinations

Abstract

The present invention concerns scintillators comprising a composition having the formula Lu_xY_(1−x)Xa₃, wherein Xa is a halide, and a dopant. The Lu_xY_(1−x)Xa₃ and dopant material has surprisingly good characteristics including high light output, high gamma-ray stopping efficiency, fast response, low cost, and minimal afterglow, thereby making the material useful for various applications including, for example, gamma-ray spectroscopy, medical imaging, nuclear and high energy physics research, diffraction, non-destructive testing, nuclear treaty verification and safeguards, geological exploration, and the like. The timing resolution of the scintillators of the present invention also provides compositions suitable for use in imaging applications, such as positron emission tomography (e.g., time-of-flight PET) and CT imaging.

Claims

1. A scintillator, comprising a composition having the formula Lu_xY₍₁₋

x)Xa₃, wherein Xa is a halide;

0≦

x≦

1; and

a dopant.

2. The scintillator of claim 1, wherein the scintillator is a fast scintillator.

3. The scintillator of claim 2, wherein the scintillator comprises a decay-time constant of less than substantially 50 nanoseconds (ns).

4. The scintillator of claim 2, wherein the scintillator comprises a decay-time constant of less than substantially 30 ns.

5. The scintillator of claim 2, wherein the scintillator comprises an initial photon intensity of greater than substantially 1000 Photons/ns×

MeV.

6. The scintillator of claim 1, wherein the scintillator comprises a light output of greater than substantially 30,000 Photons/MeV.

7. The scintillator of claim 1, wherein the scintillator comprises a light output of greater than substantially 40,000 Photons/MeV.

8. The scintillator of claim 1, wherein the halide is iodide or bromide.

9. The scintillator of claim 1, wherein X is less than 1.

10. The scintillator of claim 1, wherein X is greater than substantially 0.1.

11. The scintillator of claim 1, wherein X is substantially 0.7.

12. The scintillator of claim 8, wherein the dopant comprises Ce, La, Eu, Pr, Sm, Sr, Tl, Cl, F, or I.

13. The scintillator of claim 12, wherein the dopant comprises a mixture of at least two dopants.

14. The scintillator of claim 12, wherein said dopant is present at substantially 0.1% or more and less than or equal to substantially 100% by molar weight.

15. The scintillator of claim 12, wherein said dopant is present in an amount of from substantially 0.1% to substantially 5.0% by molar weight.

16. The scintillator of claim 12, wherein said dopant is present in an amount of from substantially 5.0% to substantially 20% by molar weight.

17. The scintillator of claim 1, wherein said dopant is Ce and present in an amount of substantially 2.0% by molar weight.

18. The scintillator of claim 17, wherein the scintillator comprises a crystal composition.

19. A radiation detection device, comprising a detector assembly comprising a scintillator comprising a composition having the formula Lu_xY₍₁₋

x)Xa₃, wherein Xa is a halide, 0<

x<

1, and a dopant; and

a light photon detection assembly.

20. The device of claim 19, wherein X is less than 1.

21. The device of claim 19, wherein X is greater than substantially 0.1.

22. The device of claim 19, wherein X is substantially 0.7.

23. The device of claim 19, wherein the halide is iodide or bromide.

24. The device of claim 23, wherein the dopant comprises Ce, La, Eu, Pr, Sm, Sr, Tl, Cl, F, or I.

25. The device of claim 19, wherein the device is a positron emission tomography (PET) imaging device.

26. The device of claim 19, wherein the device is an X-ray computed tomography (CT) imaging device.

27. The device of claim 19, wherein the device is a well-logging device.

28. The device of claim 27, wherein the scintillator comprises a crystal composition.

29. The device of claim 19, further comprising a data analysis system.

30. The device of claim 19, wherein the light photon detection assembly comprises a photomultiplier tube, a photo diode, a PIN detector, or an avalanche detector.

31. An X-ray detector assembly, comprising:

a scintillator comprising a composition having the formula Lu_xY<sub>(1−

x)</sub>Xa₃, wherein Xa is a halide, 0<

x<

1, and a dopant;

a light photon detection assembly; and

a data analysis system.

32. The assembly of claim 31, wherein the light photon detection assembly comprises a photomultiplier tube, a photo diode, a PIN detector, or an avalanche detector.

33. The assembly of claim 31, wherein the scintillator is coated with a reflective layer, a moisture resistant layer, or a vapor barrier.

34. The assembly of claim 31, wherein the assembly comprises a digital X-ray imaging device.

35. A method of performing radiation detection, comprising:

providing a detection device comprising a detector assembly comprising a scintillator comprising a composition having the formula Lu_xY<sub>(1−

x)</sub>Xa₃, wherein Xa is a halide, 0<

x<

1, and a dopant, and a light photon detection assembly; and

positioning a target within a field of view of the scintillator as to detect emissions from the target.