Hitachi Metals, Ltd.

Ryouhei Nakamura

Shunsuke Ueda

Nobuyuki Yamada

Akio Miyamoto

Kenya Tanaka

Hironari Matsumoto

A fluorescent material having a composition formula represented as (GdLCeTb)(AlGaSc)O(L is at least one element selected from Y and Lu), satisfying the following ranges: 0&#x2266;a&#x2266;0.1, 0&#x2266;b&#x2266;0.1, 0&#x2266;&#x3b1;&#x2266;0.3, 0.0003&#x2266;&#x3b2;&#x2266;0.005, 0.02&#x2266;&#x3b3;&#x2266;0.2, 0.27&#x2266;u&#x2266;0.75, and 0&#x2266;v&#x2266;0.02. Preferably, 0&#x3c;a&#x2266;0.07, 0&#x3c;b&#x2266;0.07, 0&#x3c;&#x3b1;&#x2266;0.15, 0.0003&#x2266;&#x3b2;&#x2266;0.004, 0.03&#x2266;&#x3b3;&#x2266;0.15, 0.35&#x2266;u&#x2266;0.70, and 0&#x2266;v&#x2266;0.02.

Fluorescent material, scintillator and radiation conversion panel

A polycrystalline scintillator for detecting soft X-rays, which comprises Ce as a light-emitting element and at least Y, Gd, Al, Ga and O, and has a garnet crystal structure, and a composition represented by the general formula of (YGdCe)(AlGa)O, wherein 0&#x2266;a&#x2266;0.1, 0.15&#x2266;x&#x2266;0.3, 0.002&#x2266;z&#x2266;0.015, and 0.35&#x2266;u&#x2266;0.55, with 0.05-1 ppm by mass of Fe and 0.5-10 ppm by mass of Si by outer percentage, a ratio &#x3bc;/&#x3bc;of 3 or more, wherein &#x3bc;is an absorption coefficient of X-rays at 50 keV, and &#x3bc;is an absorption coefficient of X-rays at 100 keV, and afterglow of 800 ppm or less after 3 ms from the termination of X-ray irradiation.

Polycrystalline scintillator for detecting soft X-rays

A fluorescent material for a scintillator to be used in a radiation detector is provided. The fluorescent material is designed to have a high fluorescent intensity and a low level of afterglow a short term of 1 to 300 ms after the termination of X-ray radiation. The above fluorescent material contains Ce as an activator. In addition, the material must contain at least Gd, Al, Ga, O, Fe, and a component M. The component M is at least one of Mg, Ti, and Ni. In addition, the composition of the material must be expressed by the general formula:(GdLuCe)(AlGaSc)Owherein 0&#x2266;a&#x2266;0.15, 0&#x2266;x&#x2266;0.5, 0.0003&#x2266;z&#x2266;0.0167, 0.2&#x2266;u&#x2266;0.6, and 0&#x2266;s&#x2266;0.1, and wherein, regarding the concentrations of Fe and M, Fe: 0.05&#x2266;Fe concentration (mass ppm)&#x2266;1, and 0&#x2266;M concentration (mass ppm)&#x2266;50.

Fluorescent material, scintillator using same, and radiation detector using same

Problem: The problem is to provide a fluorescent material for a scintillator to be used in a radiation detector. In view of this, the fluorescent material must have a high fluorescent intensity and a low level of afterglow 1 to 300 ms after the termination of X-ray radiation. Solution: The above problem is solved in that the above fluorescent material contains Ce as an activator. In addition, the material contain at least Gd, Al, Ga, O, Si, and a component M. The component M is at least one of Mg, Ti, and Ni. In addition, the composition of the material must be expressed by the general formula:(GdLuCe)(AlGaSc)Owherein 0&#x2266;a&#x2266;0.15, 0&#x2266;x&#x2266;0.5, 0.0003&#x2266;z&#x2266;0.0167, 0.2&#x2266;u&#x2266;0.6, and 0&#x2266;s&#x2266;0.1, and wherein, regarding the concentrations of Si and M, 0.5&#x2266;Si concentration (mass ppm)&#x2266;10, and 0&#x2266;M concentration (mass ppm)&#x2266;50.

Scintillator with both high fluorescence intensity and weak afterglow, can be offered. An aspect in accordance with the present invention provides, a fluorescent material with garnet structure containing Gd, Al, Ga, and O at least, containing Lu and/or Y, and also containing Ce as an activator, wherein said fluorescent material is expressed as (Gd1-x-zLxCez)3+a(Al1-uGau) 5-aO12, wherein L is Lu and/or Y, wherein 0&#x3c;a&#x2266;0.15, 0&#x3c;x&#x3c;1.0, 0.0003&#x2266;z&#x2266;0.0167 (here, x+z&#x3c;1.0), and 0.2&#x2266;u&#x2266;0.6.

Fluorescent material, a method of manufacturing the fluorescent material, a radiation detector using the fluorescent material, and an X-ray CT scanner

An aspect in accordance with the present invention provides, a fluorescent material with garnet structure containing Gd, Al, Ga, and O at least, containing Lu and/or Y, and also containing Ce as an activator, wherein said fluorescent material is expressed as (GdLCe)(AlGa)O, wherein L is Lu and/or Y, wherein 0&#x3c;a&#x2266;0.15, 0&#x3c;x&#x3c;1.0, 0.0003&#x2266;z&#x2266;0.0167 (here, x+z&#x3c;1.0), and 0.2&#x2266;u&#x2266;0.6.

A sintered ceramic for a scintillator having a composition represented by the general formula of Gd Ce Al Si Ga O , wherein 0.001&lE;x&lE;0.05, 1&lE;y&lE;4, and 0.0015&lE;z&lE;0.03, is produced by mixing gadolinium oxide, aluminum oxide, gallium oxide, a cerium salt, a silicon compound and a fluorine compound in such proportions as to provide the above composition; calcining the resultant mixture at a temperature of 1400-1600&deg; C.; disintegrating the resultant calcined body to ceramic powder; pressing the ceramic powder to provide a green body; and sintering the green body at a temperature of 1600-1700&deg; C. in a non-oxidizing atmosphere at 5&times;10 Pa or more, and optionally further by hot isostatic pressing at a temperature of 1400-1600&deg; C. in an argon atmosphere.

Ceramics and their power for scintillators, and method for producing same

A radiation detector element which comprises a scintillator laminate for converting X-ray energy incident on said radiation detector to visible light, the scintillator laminate comprising a ceramic scintillator layer and a single crystal scintillator layer and a photodetector for converting the visible light from the scintillator laminate to electrical signals. The single crystal scintillator is interposed in the path of the light scintillations from the ceramic scintillator to the photodetector.

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Tokorozawa, Japan

Ryouhei Nakamura