CsI(T1) scintillator crystal including antiomy and other multi valance cations to reduce afterglow, and a radiation detection apparatus including the scintillation crystal

Patent metadata

Field	Value
Publication number	US-11693133-B2
Application number	US-202217661520-A
Country	US
Kind code	B2
Filing date	Apr 29, 2022
Priority date	May 25, 2018
Publication date	Jul 4, 2023
Grant date	Jul 4, 2023

Abstract

A scintillation crystal can include a cesium halide that is co-doped with thallium and another element. In an embodiment, the scintillation crystal can include CsX:Tl, Me, where X represents a halogen, and Me represents a Group 5A element. In a particular embodiment, the scintillation crystal may have a cesium iodide host material, a first dopant including a thallium cation, and a second dopant including an antimony cation.

First claim

What is claimed is:

1. A scintillator crystal comprising:
a cesium iodide host material;
a first dopant comprising thallium;
a second dopant comprising antimony, wherein the scintillator crystal comprises between 1×10 −7 mol % and 1×10 −2 mol % antimony; and
a third dopant comprising bismuth, wherein the scintillator crystal has a reduced afterglow.

2. The scintillator crystal of claim 1 , wherein a molar concentration of the first dopant is less than 10%.

3. The scintillator crystal of claim 1 , wherein the second dopant comprises trivalent antimony.

4. The scintillator crystal of claim 1 , wherein the scintillator crystal comprises less than 1×10 −3 mol % antimony and wherein the scintillator crystal has a light output intensity of less than 0.4% at 100 ms after exposure to an X-ray irradiation, relative to a light output intensity measured during the X-ray irradiation.

5. The scintillator crystal of claim 1 , wherein the scintillator crystal comprises less than 1×10 −3 mol % antimony and wherein the scintillator crystal has a light output intensity of less than 0.3% at 500 ms after exposure to an X-ray irradiation, relative to a light output intensity measured during the X-ray irradiation.

6. The scintillator crystal of claim 1 , wherein the scintillator crystal contains more than 1×10 −6 mol % of a second codopant capable of existing in more than one oxidation state within the crystal matrix.

7. The scintillator crystal of claim 1 , wherein a concentration of the second dopant in the scintillator crystal is greater than zero and no greater than 0.003 mol %.

8. The scintillator crystal of claim 1 , wherein the second dopant comprises pentavalent antimony and the third dopant comprises pentavalent bismuth.

9. A scintillator crystal comprising:
a cesium iodide host material;
a first dopant comprising thallium;
a second dopant comprising a group VA element, wherein the scintillator crystal comprises no greater than 0.1 mol %; of the second dopant; and
a third dopant comprising bismuth.

10. The scintillator crystal of claim 9 , wherein the group VA element is at least partially in its 3+ oxidation state.

11. The scintillator crystal of claim 9 , wherein the second dopant comprises pentavalent antimony.

12. The scintillator crystal of claim 9 , wherein the scintillator crystal comprises at least 3×10 −4 mol % antimony.

13. The scintillator crystal of claim 9 , wherein the scintillator crystal comprises less than 1×10 −3 mol % antimony and wherein the scintillator crystal has a light output intensity of less than 0.5% at 100 ms after exposure to an X-ray irradiation, relative to a light output intensity measured during the X-ray irradiation.

14. The scintillator crystal of claim 9 , wherein the scintillator crystal comprises less than 1×10 −3 mol % antimony and wherein the scintillator crystal has a light output intensity of less than 0.2% at 500 ms after exposure to an X-ray irradiation, relative to a light output intensity measured during the X-ray irradiation.

15. The scintillator crystal of claim 9 , wherein the scintillator crystal contains more than 1×10 −6 mol % of the second co-dopant capable of existing in more than one oxidation state within the crystal matrix.

16. The scintillator crystal of claim 9 , wherein the scintillator crystal comprises no greater than 0.003 mol % of the second dopant.

17. A scintillator crystal formed by a growth process, comprising:
providing a cesium iodide host material;
doping with thallium, wherein a molar concentration of said thallium is less than 10%;
codoping with antimony, wherein a concentration of the second dopant in the melt is greater than zero and no greater than 0.01 mol %; and
codoping with bismuth to produce a scintillator crystal with a reduced afterglow.

18. The scintillator crystal formed by the growth process of claim 17 , wherein the growth process is a Bridgman growth process.

19. The scintillator crystal formed by the growth process of claim 17 , wherein the formed scintillator crystal comprises between 1×10 −7 mol % and 1×10 −2 mol % antimony.

20. The scintillator crystal formed by the growth process of claim 17 , wherein the formed scintillator crystal comprises no greater than 0.003 mol % antimony.

Assignees

• Saint Gobain Ceramics
• Luxium Solutions Llc

Inventors

• Meng Fang
• Menge Peter R

Classifications

• C09K11/62

  containing gallium, indium or thallium · CPC title

• G01T1/2023 Primary

  Selection of materials · CPC title

• C09K11/7435

  with alkali or alkaline earth metals · CPC title

• C09K11/628

  with alkali or alkaline earth metals · CPC title

• G21K4/00

  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) · CPC title