High energy resolution scintillators having high light output

• US 20070001118A1
• Filed: 06/29/2005
• Published: 01/04/2007
• Est. Priority Date: 06/29/2005
• Status: Active Grant

• Current Assignee: Baker Hughes Oilfield Operations LLC (Baker Hughes Company)
• Original Assignee: General Electric Company
• Inventors: Srivastava, Alok, Deng, Qun, Duclos, Steven, Comanzo, Holly, Clarke, Lucas
• Granted Patent: US 8,299,436 B2
• Time in Patent Office: Days
• US Class Current: 250/361.R
• CPC Class Codes: C04B 2235/3206 Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3208 Calcium oxide or oxide-forming salts thereof, e.g. lime
• 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 2235/3225 Yttrium oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3229 Cerium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 35/5152 based on halogenides other than fluorides
• CPC Class Codes: C09K 11/7705 with alkali or alkaline earth metals
• CPC Class Codes: C09K 11/7773 with alkali or alkaline earth metal

Abstract

A scintillator composition includes a matrix material, where the matrix material includes an alkaline earth metal and a lanthanide halide. The scintillator composition further includes an activator ion, where the activator ion is a trivalent ion. In one embodiment, the scintillator composition includes a matrix material represented by A₂LnX₇, where A includes an alkaline earth metal, Ln includes a lanthanide ion, and X includes a halide ion. In another embodiment, the scintillator composition includes a matrix material represented by ALnX₅, where A includes an alkaline earth metal, Ln includes a lanthanide ion, and X includes a halide ion. In these embodiments, the scintillator composition includes an activator ion, where the activator ion includes cerium, or bismuth, or praseodymium, or combinations thereof.

Claims

1. A scintillator composition comprising:

a matrix material comprising;

an alkaline earth metal;

a lanthanide halide, wherein the lanthanide halide comprises at least

one lanthanide ion and at least one halide ion; and

an activator ion for the matrix material, wherein the activator ion comprises a trivalent ion.

2. The scintillator composition of claim 1, wherein the alkaline earth metal comprises barium, or strontium, or calcium, or magnesium, or combinations thereof.

3. The scintillator composition of claim 1, wherein the lanthanide ion comprises lanthanum, or yttrium, or gadolinium, or lutetium, or scandium, or combinations thereof.

4. The scintillator composition of claim 1, wherein the halide ion comprises fluorine, or bromine, or chlorine, or iodine, or combinations thereof.

5. The scintillator composition of claim 1, wherein the trivalent ion comprises cerium, or bismuth, or praseodymium, or combinations thereof.

6. The scintillator composition of claim 1, wherein the molar ratio of the alkaline earth metal to the lanthanide halide ranges from about 2.2:

1 to about 1.8;

1.

7. The scintillator composition of claim 1, wherein a mole percentage of the activator ion in the matrix material ranges from about 0.1 mole percentage to about 20 mole percentage.

8. The scintillator composition of claim 1, wherein the scintillator composition comprises a substantially monocrystalline form.

9. The scintillator composition of claim 1, wherein the matrix material is represented by A₂LnX₇, wherein A comprises the alkaline earth metal, wherein Ln comprises the lanthanide ion, and wherein X comprises the halide ion.

10. The scintillator composition of claim 9, wherein A comprises barium, wherein Ln comprises yttrium, or gadolinium, or both, and wherein X comprises chlorine, or bromine, or both, and wherein the activator ion comprises cerium.

11. The scintillator composition of claim 1, wherein the matrix material is represented by ALnX₅, wherein A comprises the alkaline earth metal, wherein Ln comprises the lanthanide ion, and wherein X comprises the halide ion.

12. The scintillator composition of claim 11, wherein A comprises barium, wherein Ln comprises yttrium, or gadolinium, or both, and wherein X comprises chlorine, or bromine, or both, and wherein the activator ion comprises cerium.

13. A scintillator composition comprising:

a matrix material represented by A₂LnX₇, wherein A comprises an alkaline earth metal, wherein Ln comprises a lanthanide ion, and wherein X comprises a halide ion; and

an activator ion for the matrix material, wherein the activator ion comprises cerium, or bismuth, or praseodymium, or combinations thereof.

14. The scintillator composition of claim 13, wherein A comprises barium, or strontium, or calcium, or magnesium, or combinations thereof, wherein Ln comprises lanthanum, or yttrium, or gadolinium, or lutetium, or scandium, or combinations thereof, and wherein X comprises bromine, or chlorine, or iodine, or combinations thereof.

15. The scintillator composition of claim 13, wherein the scintillator composition is represented by A₂Ln_1-mCe_mX₇, wherein A comprises barium, wherein Ln comprises yttrium, or gadolinium, or both, and wherein X comprises chlorine, or bromine, or both, and wherein m ranges from about 0.02 to about 1.

16. A scintillator composition comprising:

a matrix material represented by ALnX₅, wherein A comprises an alkaline earth metal, wherein Ln comprises a lanthanide ion, and wherein X comprises a halide ion; and

an activator ion for the matrix material, wherein the activator ion comprises cerium, or bismuth, or praseodymium, or combinations thereof.

17. The scintillator composition of claim 16, wherein A comprises barium, or strontium, or calcium, or magnesium, or combinations thereof, wherein Ln comprises lanthanum, or yttrium, or gadolinium, or lutetium, or scandium, or combinations thereof, and wherein X comprises bromine, or chlorine, or iodine, or combinations thereof.

18. The scintillator composition of claim 16, wherein the scintillator composition is represented by ALn_1-nCe_nX₅, wherein A comprises barium, wherein Ln comprises yttrium, or gadolinium, or both, and wherein X comprises chlorine, or bromine, or both, and wherein n ranges from about 0.02 to about 1.

19. A detector element comprising:

a scintillator material configured to convert an incident radiation into photons, wherein the scintillator material comprises;

a matrix material comprising;

an alkaline earth metal;

a lanthanide halide, wherein the lanthanide halide comprises at least one lanthanide ion and at least one halide ion;

an activator ion for the matrix material, wherein the activator ion comprises cerium, or bismuth, or praseodymium, or combinations thereof; and

a photon detector optically coupled to the scintillator material and configured to convert the photons into electrical signals.

20. The detector element of claim 19, wherein the detector element comprises a nuclear imaging detector.

21. The detector element of claim 20, wherein the detector element comprises a positron emission tomography detector.

22. The detector element of claim 19, wherein the detector element comprises a well-logging tool.

23. A method of operation of a detector element comprising:

transmitting radiation through an object;

receiving the radiation by a scintillator material to produce photons which are characteristic of the radiation, wherein the scintillator material comprises;

a matrix material comprising;

an alkaline earth metal;

a lanthanide halide, wherein the lanthanide halide comprises at least one lanthanide ion and at least one halide ion;

an activator ion for the matrix material, wherein the activator ion comprises cerium, or bismuth, or praseodymium, or combinations thereof; and

detecting the photons by a photon detector optically coupled to the scintillator material and configured to convert the photons into electrical signals.