Scintillation crystal, a radiation detection system including the scintillation crystal, and a method of using the radiation detection system

Patent metadata

Field	Value
Publication number	US-10442989-B2
Application number	US-201816043374-A
Country	US
Kind code	B2
Filing date	Jul 24, 2018
Priority date	Jun 6, 2011
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

A scintillation crystal can include Ln(1-y)REyX3, 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.

First claim

What is claimed is:

1. A well logging apparatus comprising:
a scintillation crystal including La (i-y) RE y X 3 :Me 2+ , 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
Me 2+ 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:

DFPL
average

=

∫

E
lower

E
upper

⁢

DFPL
⁡

(

E
i

)

·

⁢

dE
i

E
upper

-

E
lower

,

where
DFPL(Ei) is DFPL at energy E i ;
E upper is the upper limit of the energy range; and
E lower is the lower limit of the energy range.

3. The well logging apparatus of claim 1 , wherein the concentration of Me 2+ is no greater than 0.03 wt. %.

4. The well logging apparatus of claim 1 , wherein the concentration of Me 2+ 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 (1-y) RE y X 3 :Me 2+ , 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
Me 2+ represents Sr, Ba, or any mixture thereof and has a concentration in a range of 0.0002 wt. % to 0.05 wt. %;

a photosensor optically coupled to the scintillation crystal; and
an electronics module coupled to the photosensor.

9. The medical imaging apparatus of claim 8 , 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.

10. 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.

11. The medical imaging apparatus of claim 10 , wherein the average value for the departure from perfect linearity (DFPL average ) is determined by:

DFPL
average

=

∫

E
lower

E
upper

⁢

DFPL
⁡

(

E
i

)

·

dE
i

E
upper

-

E
lower

,

where
DFPL(Ei) is DFPL at energy E i ;
E upper is the upper limit of the energy range; and
E lower is the lower limit of the energy range.

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

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

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

15. The medical imaging device of claim 8 , wherein y has a value in a range of 0.001 to 0.5.

16. A security inspection apparatus comprising:
a scintillation crystal including La (1-y) RE y X 3 :Me 2+ , 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

Me 2+ represents Sr, Ba, or any mixture thereof and has a concentration in a range of 0.0002 wt. % to 0.05 wt. %.

17. The security inspection apparatus of claim 16 , wherein the concentration of Me 2+ is no greater than 0.03 wt. %.

18. The security inspection apparatus of claim 16 , wherein the concentration of Me 2+ is in a range of 0.005 wt. % to 0.02 wt. %.

19. The security inspection apparatus of claim 16 , wherein y has a value in a range of 0.001 to 0.5.

Assignees

• Saint Gobain Ceramics

Inventors

• Menge Peter R
• Ouspenski Vladimir

Classifications

• C09K11/7773

  with alkali or alkaline earth metal · CPC title

• C04B2235/3227

  Lanthanum oxide or oxide-forming salts thereof · CPC title

• C04B2235/3213

  Strontium oxides or oxide-forming salts thereof · CPC title

• C04B2235/9646

  Optical properties · CPC title

• C04B2235/3215

  Barium oxides or oxide-forming salts thereof · CPC title