Hot wall scintillator fabrication of strontium halide, calcium halide, cerium halide, and cesium barium halide scintillators

• US 8,829,445 B1
• Filed: 04/30/2012
• Issued: 09/09/2014
• Est. Priority Date: 04/28/2011
• Status: Active Grant

• Current Assignee: Radiation Monitoring Devices, Inc. (Dynasil Corp. of America)
• Original Assignee: Radiation Monitoring Devices, Inc. (Dynasil Corp. of America)
• Inventors: Nagarkar, Vivek
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): Boosalis, Faye
• Application Number:
  US13/460,705
• Time in Patent Office: 862 Days
• Field of Search: 250/362, 250/361.R
• US Class Current: 250/362
• CPC Class Codes: C09K 11/7719 Halogenides C09K11/7716 takes precedence
• CPC Class Codes: C09K 11/7733 with alkali or alkaline earth metals
• CPC Class Codes: C09K 2211/00 Chemical nature of organic luminescent or tenebrescent compounds
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: G01T 1/20 with scintillation detectors
• CPC Class Codes: G01T 1/2006 using a combination of a scintillator and photodetector which measures the means radiation intensity
• CPC Class Codes: G01T 1/202 the detector being a crystal
• CPC Class Codes: G01T 3/06 with scintillation detectors
• CPC Class Codes: G01T 7/00 Details of radiation-measuring instruments
• CPC Class Codes: G21K 2004/06 with a phosphor layer

Abstract

Strontium halide scintillators, calcium halide scintillators, cerium halide scintillators, cesium barium halide scintillators, and related devices and methods are provided.

Claims

1. A scintillator comprising, a dopant and a scintillator material selected from the group consisting of strontium halide, calcium halide, and CsBa₂I₅, wherein the scintillator is in the form of a microcolumnar scintillator film or a noncolumnar polycrystalline film.

2. The scintillator of claim 1, wherein the dopant is Eu, Pr, Ce, Tl, Tb, or any combination thereof.

3. The scintillator of claim 1, having the formula:

SrI₂;

Eu.

4. The scintillator of claim 1, having the formula:

CaI₂;

Eu or CaI₂;

Tl.

5. The scintillator of claim 1, having the formula:

CsBa₂I₅;

Eu.

6. The scintillator of claim 1, wherein the scintillator has a thickness of less than or equal to 1 cm.

7. The scintillator of claim 1, wherein the scintillator has a thickness greater than 1 cm.

9. A radiation detection device comprising a scintillator of claim 1 or 8;

and a photodetector assembly optically coupled to the scintillator.

10. The radiation detection device of claim 9, further comprising electronics coupled to the photodetector assembly so as to output image data in response to radiation detected by the scintillator.

11. A method of performing radiation detection, comprising:

providing a detector device comprising a scintillator of claim 1 or 8; and

a photodetector assembly optically coupled to the scintillator; and

positioning a radiation source within a field of view of the scintillator so as to detect emissions from the radiation source.

8. A scintillator comprising, a scintillator material comprising cerium bromide (CeBr₃) or calcium iodide (CaI₂), wherein the scintillator is in the form of a microcolumnar scintillator film or a noncolumnar polycrystalline film.

12. A method of making a scintillator, the method comprising:

providing an evaporation apparatus comprising an evaporation chamber having a first end portion with a substrate positioned in a holder, and a second end portion with a first source boat separate from a second source boat, and one or more chamber walls at least partially disposed between the first and second end portions;

positioning a dopant salt in the first source boat and a source salt in the second source boat; and

depositing a scintillator film comprising a source and a dopant on a surface of the positioned substrate, wherein the film is deposited by a process comprising applying heat to the evaporation chamber so as to vaporize the dopant salt and the source salt for film deposition while maintaining, for at least a portion of the deposition process, a temperature of the one or more chamber walls to be greater than;

a) a temperature of the dopant salt in the first source boat and b) a temperature of the source salt in the second source boat.

13. The method of claim 12, wherein, during at least a portion of the process used to deposit the film, a temperature of the substrate is maintained to be less than:

a) the temperature of the dopant salt in the first source boat and b) the temperature of the source salt in the second source boat.

14. The method of claim 12, wherein the scintillator film comprises SrI:

Eu, CaI₂;

Eu, CaI₂;

Tl, or CsBa₂I₅;

Eu.

15. The method of claim 12, wherein the dopant salt comprises Eu, Pr, Ce, Tl, Tb, or any combination thereof.

16. The method of claim 12, wherein the dopant salt comprises EuI.

17. A scintillator produced by the method of claim 12.

18. The method of claim 17, wherein the scintillator film comprises CeBr₃ or CaI.

19. The method of claim 12, wherein the source salt is selected from the group consisting of strontium halide, calcium halide, and CsBa₂I₅.

20. A method for making a scintillator film, the method comprising:

providing an evaporation apparatus comprising an evaporation chamber having a first end portion with a substrate positioned in a holder, and a second end portion with a source boat, and one or more chamber walls at least partially disposed between the first and second end portions;

positioning a calcium halide source material in the source boat; and

depositing a scintillator film on a surface of the positioned substrate to form the scintillator film, wherein the scintillator film comprises calcium halide.