SOLID SCINTILLATOR, RADIATION DETECTOR, AND TOMOGRAPH

• US 20110303873A1
• Filed: 02/22/2010
• Published: 12/15/2011
• Est. Priority Date: 02/23/2009
• 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, Oota, Hiroyasu, Ishii, Tsutomu, Funayama, Yoshitaka
• Granted Patent: US 8,377,335 B2
• Time in Patent Office: Days
• US Class Current: 252/301.4R
• CPC Class Codes: A61B 6/03 Computed tomography [CT] echo-tomography A61B8/14
• 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: C01G 19/006 Compounds containing, besides tin, two or more other elements, with the exception of oxygen or hydrogen
• CPC Class Codes: C01G 56/00 Compounds of transuranic elements
• CPC Class Codes: C01P 2002/50 Solid solutions
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: C01P 2006/80 Compositional purity
• CPC Class Codes: C04B 2235/3215 Barium oxides or oxide-forming salts thereof
• 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 2235/3286 Gallium oxides, gallates, indium oxides, indates, thallium oxides, thallates or oxide forming salts thereof, e.g. zinc gallate
• CPC Class Codes: C04B 2235/3418 Silicon oxide, silicic acids, or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint glass constituents C04B2235/36
• CPC Class Codes: C04B 2235/445 Fluoride containing anions, e.g. fluosilicate
• CPC Class Codes: C04B 2235/5436 micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/662 Annealing after sintering
• CPC Class Codes: C04B 2235/764 Garnet structure A3B2(CO4)3
• CPC Class Codes: C04B 2235/85 Intergranular or grain boundary phases
• CPC Class Codes: C04B 2235/9653 Translucent or transparent ceramics other than alumina
• CPC Class Codes: C04B 35/01 : based on oxide ceramics
• CPC Class Codes: C04B 35/44 : based on aluminates
• CPC Class Codes: C04B 35/645 : Pressure sintering
• CPC Class Codes: C04B 35/6455 : Hot isostatic pressing
• CPC Class Codes: C09K 11/7774 : Aluminates
• CPC Class Codes: G21K 2004/06 : with a phosphor layer
• 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

An object of the present invention is to provide a solid scintillator having short afterglow and high output, and a radiation detector and a tomograph using the solid scintillator. A solid scintillator according to the present invention is a solid scintillator comprising a polycrystal containing a crystal of a Gd garnet structure oxide having a composition ratio represented by the following formula (1):

[Formula 1]

(M_1-x-yGd_xQ_y)₃J₅O₁₂  (1)

wherein M is at least one element of La and Tb, Q is at least one element of Ce and Pr, J is at least one element selected from Al, Ga, and In, x and y satisfy relations 0.5≦x≦1, and 0.000001≦y≦0.2,
and further containing Si and fluorine, wherein the solid scintillator contains 1 ppm by mass to 1000 ppm by mass of the Si with respect to the Gd garnet structure oxide, and 1 ppm by mass to 100 ppm by mass of the fluorine with respect to the Gd garnet structure oxide.

Claims

1. A solid scintillator comprising a polycrystal containing a crystal of a Gd garnet structure oxide having a composition ratio represented by the following formula (1):

[Formula 1]

(M_1-x-yGd_xQ_y)₃J₅O₁₂ 

 

(1)

wherein M is at least one element of La and Tb, Q is at least one element of Ce and Pr, J is at least one element selected from Al, Ga, and In, x and y satisfy relations 0.5≦

x≦

1, and 0.000001≦

y≦

0.2,

and further containing Si and fluorine,

wherein the solid scintillator contains 1 ppm by mass to 1000 ppm by mass of the Si with respect to the Gd garnet structure oxide, and 1 ppm by mass to 100 ppm by mass of the fluorine with respect to the Gd garnet structure oxide.

2. A radiation detector using the solid scintillator according to claim 1.

3. A tomograph using the radiation detector according to claim 2.