Solid scintillator, radiation detector, and X-ray tomographic imaging apparatus

• US 8,083,968 B2
• Filed: 02/23/2009
• Issued: 12/27/2011
• Est. Priority Date: 03/10/2008
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Materials Company Limited (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Materials Company Limited (Toshiba Corporation)
• Inventors: Fukuta, Yukihiro, Okamura, Masami, Shirakawa, Yasuhiro
• Primary Examiner(s): Lorengo, Jerry
• Assistant Examiner(s): EDMONDSON, LYNNE RENEE
• Application Number:
  US12/922,033
• Publication Number:
  US 20110024684A1
• Time in Patent Office: 1,037 Days
• Field of Search: 252/301.4 R, 252/301.17, 250/361.R, 250/390.11
• US Class Current: 252/301.4R
• CPC Class Codes: C01F 17/34 Aluminates, e.g. YAlO3 or Y3-xGdxAl5O12
• CPC Class Codes: C01G 15/006 Compounds containing, besides gallium, indium, or thallium, two or more other elements, with the exception of oxygen or hydrogen
• CPC Class Codes: C01P 2002/50 Solid solutions
• CPC Class Codes: C01P 2002/84 by UV- or VIS- data
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• 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 2235/5436 micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/764 Garnet structure A3B2(CO4)3
• CPC Class Codes: C04B 35/44 based on aluminates
• CPC Class Codes: C04B 35/645 Pressure sintering
• CPC Class Codes: C09K 11/7769 Oxides C09K11/7768 takes precedence
• CPC Class Codes: C09K 11/7774 Aluminates

Abstract

The solid scintillator according to the present invention is expressed by the following formula (1):

[Formula 1]
(M_1-x-yGd_xCe_y)₃J₅O₁₂  (1)

(wherein M is at least one element of La and Tb; J is at least one metal selected from the group consisting of Al, Ga, and In; and x and y are such that 0.5≦x≦1 and 0.000001≦y≦0.2). The transmittance of light having a wavelength of 550 nm measured at a thickness of 2 mm is equal to or greater than 40%. The solid scintillator according to the present invention can be manufactured at low cost, has a high light emitting power, and does not release Cd because Cd is not contained.

Claims

1. A solid scintillator represented by the following formula (1):

(Tb_1-x-yGd_xCe_y)₃J₅O₁₂ 

 

(1)

wherein

J is at least one metal selected from the group consisting of Al, Ga, and In; and

x and y are

0.5<

x<

1 and

0.000001≦

y≦

0.2,

wherein transmittance of light having a wavelength of 550 nm measured at a thickness of 2 mm is equal to or greater than 40%.

3. A radiation detector comprising the solid scintillator according to claim 1.

4. An x-ray tomographic imaging apparatus comprising the radiation detector according to claim 3.

7. The solid scintillator according to claim 1, wherein:

0.6≦

x<

1.

8. The solid scintillator according to claim 1, wherein:

0.001≦

y≦

0.1.

9. The solid scintillator according to claim 1, wherein J is Al.

10. The solid scintillator according to claim 1, wherein J is Ga.

11. The solid scintillator according to claim 1, wherein J is In.

12. The solid scintillator according to claim 1, which is

(Tb_0.3Gd_0.6Ce_0.1)₃Ga₅O₁₂.

13. A radiation detector comprising the solid scintillator according to claim 12.

2. A solid scintillator represented by the following formula (2):

(Tb_1-x-yGd_xPr_y)₃J₅O₁₂ 

 

(2)

wherein

J is at least one metal selected from the group consisting of Al, Ga, and In; and

x and y are

0.5<

x<

1 and

0.000001≦

y≦

0.2,

wherein transmittance of light having a wavelength of 610 nm measured at a thickness of 2 mm is equal to or greater than 40%.

5. A radiation detector comprising the solid scintillator according to claim 2.

6. An x-ray tomographic imaging apparatus comprising the radiation detector according to claim 5.

14. The solid scintillator according to claim 2, wherein:

0.69≦

x<

1.

15. The solid scintillator according to claim 2, wherein:

0.0001≦

y≦

0.01.

16. The solid scintillator according to claim 2, wherein J is Al.

17. The solid scintillator according to claim 2, wherein J is Ga.

18. The solid scintillator according to claim 2, wherein J is In.

19. The solid scintillator according to claim 2, which is

(Tb_0.3Gd_0.6Ce_0.1)₃Ga₅O₁₂.

20. A radiation detector comprising the solid scintillator according to claim 19.