Cesium and sodium-containing scintillator compositions

• US 8,575,553 B1
• Filed: 11/09/2007
• Issued: 11/05/2013
• Est. Priority Date: 11/09/2007
• Status: Active Grant

• Current Assignee: Radiation Monitoring Devices, Inc. (Dynasil Corp. of America)
• Original Assignee: Radiation Monitoring Devices, Inc. (Dynasil Corp. of America)
• Inventors: Shah, Kanai S., Higgins, William M., Van Loef, Edgar V., Glodo, Jaroslaw
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): BOOSALIS, FANI POLYZOS
• Application Number:
  US11/938,182
• Time in Patent Office: 2,188 Days
• Field of Search: 250/361.R, 250/367, 250/370.11, 250/458.1, 250/363.03, 250/363.04
• US Class Current: 250/361.R
• CPC Class Codes: C09K 11/7773 with alkali or alkaline earth metal
• CPC Class Codes: C30B 29/12 Halides
• CPC Class Codes: G21K 2004/06 with a phosphor layer
• CPC Class Codes: G21K 4/00 Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens photographic processes using X-ray intensifiers G03C5/17; discharge tubes comprising luminescent screens H01J1/62; cathode ray tubes for X-ray conversion with optical output H01J31/50

Abstract

The present invention relates to scintillator compositions and related devices and methods. The scintillator compositions may include, for example, a scintillation compound and a dopant, the scintillation compound having the formula x₁-x₂-x₃-x₄ and x₁ is Cs; x₂ is Na; x₃ is La, Gd, or Lu; and x₄ is Br or I. In certain embodiments, the scintillator composition can include a single dopant or mixture of dopants.

Claims

1. A scintillator composition, comprising a scintillation compound and a dopant, the scintillation compound having the formula, Cs₂NaMI₆, wherein:

M is La, Gd, or Lu.

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

3. The scintillator composition of claim 2, wherein the scintillator composition comprises a fast decay-time constant is less than about 60 ns.

4. The scintillator composition of claim 1, wherein the scintillator composition comprises a light output of greater than about 10,000 Photons/MeV.

5. The scintillator composition of claim 1, wherein the scintillator composition comprises x₃ as Gd and a sensitivity to both energetic photons and to neutrons.

6. The scintillator composition of claim 1, wherein the dopant comprises Ce, Lu, La, Eu, Pr, Sm, Sr, Tl, Cl, F, or I.

7. The scintillator composition of claim 6, wherein the dopant is present at less than about 20% by molar weight.

8. The scintillator composition of claim 1, wherein the dopant is Ce and present at equal to or less than about 5% by molar weight.

9. The scintillator composition of claim 1, wherein the scintillation composition comprises Cs₂NaGdI₆:

Ce, Cs₂NaLaI₆;

Ce, or Cs₂NaLuI₆;

Ce.

10. A radiation detection device, comprising a scintillator composition comprising Cs₂NaGdI₆:

Ce, Cs₂NaLaI₆;

Ce, or Cs₂NaLuI₆;

Ce; and

a photodetector assembly optically coupled to the scintillator.

11. The device of claim 10, wherein the photodetector assembly comprises a photomultiplier tube, a photodiode, a PIN detector, charge-coupled device, or an avalanche detector.

12. The device of claim 10, further comprising a radiation source.

13. The device of claim 10, further comprising a computer system coupled to the photodetector assembly so that the computer outputs image data in response to detected radiation.

14. The device of claim 13, wherein the computer comprises instructions for constructing an image from detected radiation.

15. The device of claim 10, wherein the device is configured to detect x-rays, gamma-rays, neutron emissions, or a combination thereof.

16. A gamma-ray and neutron detection device, comprising:

a scintillator composition comprising a scintillation compound and a dopant, the scintillation compound having the formula, Cs₂NaMI₆, wherein

M is La, Gd, or Lu;

a photodetector assembly optically coupled to the scintillator; and

electronics configured for performing pulse-shape analysis to differentiate gamma-ray detections from neutron detections.

17. The device of claim 16, further comprising a radiation source.

18. The device of claim 16, further comprising a computer system coupled to the photodetector assembly so that the computer outputs image data in response to detected radiation.

19. The device of claim 16, wherein the scintillator composition further comprises a reflective layer, a moisture resistant layer, or a vapor barrier.

20. A method of performing radiation detection, comprising:

providing a detection device comprising a scintillator composition comprising a scintillation compound, the scintillation compound having the formula, Cs₂NaMI₆, wherein

M is La, Gd, or Lu

and a photodetector assembly optically coupled to the scintillator; and

positioning the device such that a radiation source is within a field of view of the scintillator composition so as to detect emissions from the source.

21. The method of claim 20, wherein the emissions comprise gamma-ray or X-ray emissions.

22. The method of claim 20, wherein x₃ is Gd and the emissions comprise neutron emissions.

23. The method of claim 20, wherein a patient is positioned between the radiation source and the scintillator composition.

24. The method of claim 20, wherein the radiation source comprises a patient.