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

Patent metadata

Field	Value
Publication number	US-10928526-B2
Application number	US-201916422612-A
Country	US
Kind code	B2
Filing date	May 24, 2019
Priority date	May 25, 2018
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

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 a thallium cation, a molar concentration of said first dopant being less than 10%; and
a second dopant comprising an antimony cation, the second dopant resulting in the scintillator having a reduced afterglow, wherein a concentration of the second dopant in the scintillator crystal is greater than zero and no greater than 0.01 mol %.

2. The scintillator crystal of claim 1 , wherein the quantity of the antimony in the scintillator crystal comprises between 1×10 −7 mol % and 1×10 −2 mol % antimony.

3. The scintillator crystal of claim 1 , wherein the scintillator crystal comprises at least 1×10 −7 mol % 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 co-dopant cation capable of existing in more than one oxidation state within the crystal matrix.

7. A scintillator crystal comprising:
a cesium iodide host material;
a first dopant comprising a thallium cation, a molar concentration of said first dopant being less than 10%; and
a second dopant comprising a group VA element, wherein the group VA element is at least partially in its 3+oxidation state, wherein the quantity of the second dopant in the scintillator comprises between 1×10 −7 mol % and 0.1 mol %.

8. The scintillator crystal of claim 7 , further comprising a third dopant, and wherein the second dopant comprises trivalent antimony and the third dopant comprises trivalent bismuth.

9. The scintillator crystal of claim 7 , further comprising a third dopant, and wherein the second dopant comprises pentavalent bismuth and the third dopant comprises pentavalent antimony.

10. The scintillator crystal of claim 7 , wherein the scintillator crystal comprises at least 3×10 −4 mol % antimony.

11. The scintillator crystal of claim 7 , 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.

12. The scintillator crystal of claim 7 , 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.

13. The scintillator crystal of claim 7 , wherein the scintillator crystal contains more than 1×10 −6 mol % of a co-dopant cation capable of existing in more than one oxidation state within the crystal matrix.

14. The scintillator crystal of claim 7 , wherein the scintillator crystal comprises no greater than 0.003 mol % of the second dopant.

15. A radiation detection apparatus comprising:
a housing;
a scintillator within the housing, the scintillator comprising:
a cesium iodide host material;

a first dopant comprising a thallium cation, a molar concentration of said first dopant being less than 10%; and
a second dopant comprising a antimony cation, the second dopant resulting in the scintillator having a reduced afterglow, wherein a concentration of the second dopant in the scintillator crystal is greater than zero and no greater than 0.01 mol %.

16. The radiation detection apparatus of claim 15 , wherein the scintillator crystal comprises no greater than 0.002 mol % of the second dopant.

17. The radiation detection apparatus of claim 15 , wherein the radiation detection apparatus is capable of inspecting more than 300 bags per hour during an X-ray irradiation.

18. The radiation detection apparatus of claim 15 , wherein the radiation detection apparatus is capable of inspecting more than 1000 bags per hour during an Computed tomography irradiation.

19. The radiation detection apparatus of claim 15 , wherein the afterglow is reduced by at least 20%.

Assignees

• Saint Gobain Ceramics

Inventors

• Meng Fang
• Menge Peter R

Classifications

• C09K11/628

  with alkali or alkaline earth metals · CPC title

• C09K11/756

  with alkali or alkaline earth metals · CPC title

• G01T1/2023 Primary

  Selection of materials · CPC title

• C09K11/62

  containing gallium, indium or thallium · 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