SCINTILLATION CRYSTAL, A RADIATION DETECTION SYSTEM INCLUDING THE SCINTILLATION CRYSTAL, AND A METHOD OF USING THE RADIATION DETECTION SYSTEM

• US 20180327663A1
• Filed: 07/24/2018
• Published: 11/15/2018
• Est. Priority Date: 06/06/2011
• Status: Active Grant

• Current Assignee: Luxium Solutions LLC
• Original Assignee: Saint-Gobain Ceramics & Plastics Incorporated (Compagnie De Saint-Gobain)
• Inventors: Menge, Peter R., Ouspenski, Vladimir
• Granted Patent: US 10,442,989 B2
• Time in Patent Office: Days
• CPC Class Codes: C04B 2235/3206 Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3213 Strontium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3215 Barium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3224 Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3227 Lanthanum oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3229 Cerium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3284 Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof
• CPC Class Codes: C04B 2235/9646 Optical properties
• CPC Class Codes: C04B 35/5152 based on halogenides other than fluorides
• CPC Class Codes: C04B 35/553 based on fluorides
• CPC Class Codes: C09K 11/7772 Halogenides C09K11/7767 takes precedence
• CPC Class Codes: C09K 11/7773 with alkali or alkaline earth metal
• CPC Class Codes: C30B 11/04 adding crystallising materials or reactants forming it in situ to the melt
• CPC Class Codes: C30B 15/04 adding doping materials, e.g. for n-p-junction
• CPC Class Codes: C30B 29/12 Halides
• CPC Class Codes: G01T 1/202 the detector being a crystal
• 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

A scintillation crystal can include Ln_(1-y)RE_yX₃, wherein Ln represents a rare earth element, RE represents a different rare earth element, y has a value in a range of 0 to 1, and X represents a halogen. In an embodiment, RE is Ce, and the scintillation crystal is doped with Sr, Ba, or a mixture thereof at a concentration of at least approximately 0.0002 wt. %. In another embodiment, the scintillation crystal can have unexpectedly improved linearity and unexpectedly improved energy resolution properties. In a further embodiment, a radiation detection system can include the scintillation crystal, a photosensor, and an electronics device. Such a radiation detection system can be useful in a variety of radiation imaging applications.

Claims

1. A well logging apparatus comprising:

a scintillation crystal including La<sub>(1−

y)</sub>RE_yX₃;

Me²⁺, wherein;

RE represents a rare earth element other than La;

y has a value in a range of 0 to 1;

X represents a halogen; and

Me²⁺ represents Sr, Ba, or any mixture thereof; and

wherein the scintillation crystal has a property including;

for a radiation energy range of 60 keV to 356 keV, the scintillation crystal has an average value for a departure from perfect linearity of no less than −

0.35%;

for a radiation energy range of 2000 keV to 2600 keV, the scintillation crystal has an average value for a departure from perfect linearity of no greater than 0.07%;

for a radiation energy range of 60 keV to 356 keV, the scintillation crystal has an absolute value for a furthest departure from perfect linearity of no greater than 0.7%;

or

any combination thereof.

2. The well logging apparatus of claim 1, wherein the average value for the departure from perfect linearity (DFPL_average) is determined by:

3. The well logging apparatus of claim 1, wherein the concentration of Me²⁺ is no greater than 0.03 wt. %.

4. The well logging apparatus of claim 1, wherein the concentration of Me²⁺ is in a range of 0.005 wt. % to 0.02 wt. %.

5. The well logging apparatus of claim 1, wherein y has a value in a range of 0.001 to 0.5.

6. The well logging apparatus of claim 1, wherein RE is Ce.

7. The well logging apparatus of claim 1, wherein X is Br.

8. A medical imaging apparatus comprising:

a scintillation crystal including La<sub>(1−

y)</sub>RE_yX₃;

Me²⁺, wherein;

RE represents a rare earth element other than La;

y has a value in a range of 0 to 1;

X represents a halogen; and

Me²⁺ represents Sr, Ba, or any mixture thereof; and

a photosensor optically coupled to the scintillation crystal.

9. The medical imaging apparatus of claim 8, further comprising an electronics module coupled to the photosensor.

10. The medical imaging apparatus of claim 9, wherein the electronics module comprises an amplifier, a pre-amplifier, a discriminator, an analog-to-digital signal converter, a photon counter, another electronic component, or any combination thereof.

11. The medical imaging apparatus of claim 8, wherein the scintillation crystal has a property including:

for a radiation energy range of 60 keV to 356 keV, the scintillation crystal has an average value for a departure from perfect linearity of no less than −

0.35%;

for a radiation energy range of 2000 keV to 2600 keV, the scintillation crystal has an average value for a departure from perfect linearity of no greater than 0.07%;

for a radiation energy range of 60 keV to 356 keV, the scintillation crystal has an absolute value for a furthest departure from perfect linearity of no greater than 0.7%;

or

any combination thereof.

12. The medical imaging apparatus of claim 11, wherein the average value for the departure from perfect linearity (DFPL_average) is determined by:

13. The medical imaging apparatus of claim 8, wherein RE is Ce, and X is Br.

15. The medical imaging apparatus of claim 8, wherein the medical imaging device is a positron emission tomography apparatus.

16. The medical imaging apparatus of claim 8, wherein the medical imaging device is a single positron emission computer tomography apparatus.

17. A security inspection apparatus comprising:

a scintillation crystal including La<sub>(1−

y)</sub>RE_yX₃;

Me²⁺, wherein;

RE represents a rare earth element other than La;

y has a value in a range of 0 to 1;

X represents a halogen; and

Me²⁺ represents Sr, Ba, or any mixture thereof and has a concentration in a range of 0.0002 wt. % to 0.05 wt. %.

18. The security inspection apparatus of claim 17, wherein the concentration of Me²⁺ is no greater than 0.03 wt. %.

19. The security inspection apparatus of claim 17, wherein the concentration of Me²⁺ is in a range of 0.005 wt. % to 0.02 wt. %.

20. The security inspection apparatus of claim 17, wherein y has a value in a range of 0.001 to 0.5.