JPS648676B2 - - Google Patents
Info
- Publication number
- JPS648676B2 JPS648676B2 JP8626982A JP8626982A JPS648676B2 JP S648676 B2 JPS648676 B2 JP S648676B2 JP 8626982 A JP8626982 A JP 8626982A JP 8626982 A JP8626982 A JP 8626982A JP S648676 B2 JPS648676 B2 JP S648676B2
- Authority
- JP
- Japan
- Prior art keywords
- scintillation
- detector
- scintillation detector
- present
- detectors
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000000126 substance Substances 0.000 claims description 9
- 229910052688 Gadolinium Inorganic materials 0.000 claims description 7
- 229910052777 Praseodymium Inorganic materials 0.000 claims description 3
- 229910052771 Terbium Inorganic materials 0.000 claims description 3
- 150000001875 compounds Chemical class 0.000 claims description 2
- 238000000465 moulding Methods 0.000 claims 2
- 238000001513 hot isostatic pressing Methods 0.000 claims 1
- 238000007731 hot pressing Methods 0.000 claims 1
- 230000005855 radiation Effects 0.000 description 8
- 238000002591 computed tomography Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Measurement Of Radiation (AREA)
- Luminescent Compositions (AREA)
Description
[発明の目的]
(産業上の利用分野)
本発明はX線CT(コンピユータトモグラフイ)
用やガンマカメラ用等の検出器に使用される高い
分解能を有するシンチレーシヨン検出器に関す
る。
(従来の技術)
従来よりX線CT等に用いられる放射線検出器
として、キセノンガスを使用したイオン化検出器
が知られているが、このイオン化検出器は、イオ
ン電流の残留効果が大きいため、運動する被写体
については検出が困難であり、また分解能が悪い
ため、細部の検出ができないという欠点があつ
た。このため無機化合物の螢光物質を粉状あるい
は単結晶状態で使用したシンチレーシヨン検出器
の使用が検討されている。
このシンチレーシヨン検出器は適切なシンチレ
ータ材料を選ぶとイオン化検出器に比べてシンチ
レーシヨンの残留効果が小さく、また充填密度が
大きいため検出器の容積を小さくできて分解能の
向上が期待でき、しかも振動や雑音に対して感応
しにくいという利点を有しているが、螢光物質を
粉状で使用する場合は散乱や乱反射により発光出
力が低下し、また単結晶状態で使用する場合は製
造が困難でコスト高になる欠点があつた。
また、螢光物質のうち汎用されている
Bi4Ge3O12、CdWO4では発光効率が低いため、X
線の照射量を多くする必要があるという欠点があ
つた。また多くの螢光物質では残光が多いという
難点もある。
(発明が解決しようとする問題点)
本発明者らはこのような欠点を解消するため鋭
意研究を進めたところ、特定の螢光物質を特定の
温度および圧力のもとにホツトプレスまたはホツ
トアイソスタテイクプレスすることにより、発光
効率が大きくかつ残光の小さいシンチレーシヨン
検出器を簡単に製造することができることを見出
した。
本発明はこのような知見に基づいてなされたも
ので、発光効率が大きく、残光(シンチレーシヨ
ンの残留効果)の小さいシンチレーシヨン検出器
を提供することを目的とする。
[発明の構成]
(問題点を解決するための手段)
本発明のシンチレーシヨン検出器は、
Gd2O2S:Pr、(Y,Gd)O2S:Prおよび(Y,
Gd)O2S:(Tb,Pr)からなる化合物群から選
ばれた1種または2種以上の螢光物質を、1000〜
2000℃の温度で10〜10000Kg/cm2の圧力下でホツ
トプレスまたはホツトアイソスタテイクプレスに
より成形してなることを特徴とする。
本発明に使用する螢光物質としては、特にPr
でドープされたGd2O2S(Gd2O2S:Pr)およびこ
れとPrおよび/またはTbでドープされたY2O2S
との固溶体[(Y,Gd)O2S:Pr、(Y,Gd)
O2S:(Tb,Pr)]が適している。これらの物質
から得られるシンチレーシヨン検出器は発光効率
が大きく、かつ残光が小さく、これを放射線検出
器に使用した場合高い分解能を有し、高速スキヤ
ンが可能な放射線検出器を得ることができる。な
お、これらの螢光物質はできるだけ高純度のもの
を使用することが望ましい。なお、これらの螢光
物質のうち特に好ましいものは、Gd2O2S:Pr、
(Y,Gd)O2S:Prなどである。
(作用)
本発明においては、上述の螢光物質をヘリウ
ム、アルゴン等の不活性ガス雰囲気中で1000〜
2000℃の温度で10〜10000Kg/cm2の圧力下でホツ
トプレスまたはホツトアイソスタテイクプレスに
よりブロツク状に成形する。好ましいプレス条件
は、温度1600℃〜1800℃であり、圧力300〜3000
Kgf/cm2である。
このようにして製造されたシンチレーターを所
定の大きさおよび形状に機械加工することにより
性能の均一な多数個のシンチレーシヨン検出器を
得ることができる。
(実施例)
次に本発明の実施例について説明する。
実施例
第1表に示す螢光物質をヘリウム雰囲気下で温
度800〜1800℃、圧力300〜1000Kg/cm2の条件でホ
ツトアイソスタテイクプレスを行なつて、厚さ30
mmの焼結体を得た。これを適当な大きさに加工
し、それぞれホトダイオードにマウントしてシン
チレーシヨン検出器を製造した。
このようにして得られたシンチレーシヨン検出
器の発光出力(フオトダイオードの出力)および
残光は次表の通りであつた。
[Object of the invention] (Industrial application field) The present invention is an X-ray CT (computer tomography)
This invention relates to scintillation detectors with high resolution used for detectors such as cameras and gamma cameras. (Prior art) Ionization detectors using xenon gas have been known as radiation detectors used in X-ray CT, etc., but this ionization detector has a large residual effect of ion current, so However, it is difficult to detect objects that are close to the camera, and because the resolution is poor, it is difficult to detect fine details. For this reason, the use of scintillation detectors using inorganic fluorescent substances in powder or single crystal form is being considered. This scintillation detector has a smaller residual effect of scintillation than an ionization detector by selecting the appropriate scintillator material, and has a large packing density, so the detector volume can be reduced and resolution can be expected to be improved. However, when the fluorescent substance is used in powder form, the light emission output decreases due to scattering and diffused reflection, and when it is used in a single crystal form, it is difficult to manufacture. The drawback was that it was expensive. In addition, among the fluorescent materials, commonly used
Since the luminous efficiency of Bi 4 Ge 3 O 12 and CdWO 4 is low,
The drawback was that it required a large amount of radiation. Another problem with many fluorescent materials is that they produce a lot of afterglow. (Problems to be Solved by the Invention) The present inventors have carried out intensive research in order to eliminate these drawbacks, and have found that a specific fluorescent substance is hot pressed or hot isostatically heated at a specific temperature and pressure. It has been found that a scintillation detector with high luminous efficiency and low afterglow can be easily manufactured by take-pressing. The present invention was made based on such knowledge, and an object of the present invention is to provide a scintillation detector with high luminous efficiency and low afterglow (residual scintillation effect). [Configuration of the Invention] (Means for Solving the Problems) The scintillation detector of the present invention has the following features:
Gd 2 O 2 S: Pr, (Y, Gd) O 2 S: Pr and (Y,
Gd) O 2 S: One or more fluorescent substances selected from the compound group consisting of (Tb, Pr),
It is characterized by being formed by hot press or hot isostatic press at a temperature of 2000°C and a pressure of 10 to 10000 kg/cm 2 . As the fluorescent substance used in the present invention, Pr
Gd 2 O 2 S doped with (Gd 2 O 2 S:Pr) and Y 2 O 2 S doped with Pr and/or Tb
Solid solution with [(Y,Gd)O 2 S: Pr, (Y,Gd)
O 2 S: (Tb, Pr)] is suitable. Scintillation detectors obtained from these materials have high luminous efficiency and low afterglow, and when used in radiation detectors, it is possible to obtain radiation detectors that have high resolution and are capable of high-speed scanning. . Note that it is desirable to use these fluorescent substances with as high a purity as possible. Note that among these fluorescent substances, particularly preferable ones are Gd 2 O 2 S:Pr,
(Y,Gd) O2S :Pr, etc. (Function) In the present invention, the above-mentioned fluorescent substance is used in an atmosphere of an inert gas such as helium or argon to
It is molded into a block using a hot press or hot isostatic press at a temperature of 2000°C and a pressure of 10 to 10000 kg/cm 2 . Preferred press conditions are temperature 1600℃~1800℃ and pressure 300~3000℃.
Kgf/ cm2 . By machining the scintillator thus manufactured into a predetermined size and shape, a large number of scintillation detectors with uniform performance can be obtained. (Example) Next, an example of the present invention will be described. Example The fluorescent materials shown in Table 1 were hot isostatically pressed in a helium atmosphere at a temperature of 800 to 1,800°C and a pressure of 300 to 1,000 kg/cm 2 to a thickness of 30 kg.
A sintered body of mm was obtained. This was processed into an appropriate size and mounted on a photodiode to manufacture a scintillation detector. The light emission output (output of the photodiode) and afterglow of the scintillation detector thus obtained were as shown in the following table.
【表】
次に本発明のシンチレーシヨン検出器をX線
CTに使用した例について説明する。
図において回転X線源1は、ほぼ平担な扇形放
射線ビーム2を射出し、これが検体3を通過す
る。射出放射線ビーム2は検体3を通過した後シ
ンチレーシヨン検出器4に衝突する。なお、シン
チレーシヨン検出器4は通常モリブデン板等の遮
蔽体により分離されているが、本発明においては
検出器でのX線の吸収が大であるため特に必要で
はないという利点がある。
次にシンチレーシヨン検出器4により発光した
光をフオトダイオード(図示せず)により電気信
号に変換する。このようにして検体3の外周をス
キヤンして得られる多数の透通X線強度を示す電
気信号を高速コンピユータによつて合成すること
により、検体3の断面が得られる。
[発明の効果]
以上の実施例からも明らかなように本発明のシ
ンチレーシヨン検出器は、発光効率が大きいので
検出器を小さくすることができまた、残光が小さ
いので高い分解能が得られ、これを放射線検出器
に用いた場合、運動する被写体についての検出や
高速スキヤンが可能になる。[Table] Next, the scintillation detector of the present invention was
An example of use in CT will be explained. In the figure, a rotating X-ray source 1 emits a substantially flat fan-shaped radiation beam 2 which passes through a specimen 3. After passing through the specimen 3, the exit radiation beam 2 impinges on a scintillation detector 4. The scintillation detector 4 is normally separated by a shield such as a molybdenum plate, but in the present invention there is an advantage that this is not particularly necessary since the detector absorbs a large amount of X-rays. Next, the light emitted by the scintillation detector 4 is converted into an electrical signal by a photodiode (not shown). By scanning the outer periphery of the specimen 3 in this manner and synthesizing the electric signals representing the transmitted X-ray intensities using a high-speed computer, a cross section of the specimen 3 is obtained. [Effects of the Invention] As is clear from the above examples, the scintillation detector of the present invention has high luminous efficiency, so the detector can be made small, and low afterglow, so high resolution can be obtained. When used in a radiation detector, it becomes possible to detect moving subjects and perform high-speed scanning.
図はX線CT装置に本発明のシンチレーシヨン
検出器を使用した例を示す概略断面図である。
1……回転X線源、2……放射線ビーム、3…
…検体、4……シンチレーシヨン検出器。
The figure is a schematic sectional view showing an example in which the scintillation detector of the present invention is used in an X-ray CT apparatus. 1... Rotating X-ray source, 2... Radiation beam, 3...
...Sample, 4...Scintillation detector.
Claims (1)
(Y,Gd)O2S:(Tb,Pr)からなる化合物群か
ら選ばれた1種または2種以上の螢光物質をプレ
ス成形してなることを特徴とするシンチレーシヨ
ン検出器。 2 プレス成形は、温度1000〜2000℃、圧力10〜
10000Kg/cm2で行うホツトプレスまたはホツトア
イソスタテイツクプレスによる特許請求の範囲第
1項に記載のシンチレーシヨン検出器。[Claims] 1. One species selected from the group of compounds consisting of Gd 2 O 2 S: Pr, (Y, Gd) O 2 S: Pr, and (Y, Gd) O 2 S: (Tb, Pr). Or a scintillation detector characterized by being formed by press-molding two or more types of fluorescent substances. 2 Press molding is performed at a temperature of 1000~2000℃ and a pressure of 10~
The scintillation detector according to claim 1, which is produced by hot pressing or hot isostatic pressing at 10,000 kg/cm 2 .
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8626982A JPS58204088A (en) | 1982-05-21 | 1982-05-21 | Scintillation detector |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8626982A JPS58204088A (en) | 1982-05-21 | 1982-05-21 | Scintillation detector |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS58204088A JPS58204088A (en) | 1983-11-28 |
JPS648676B2 true JPS648676B2 (en) | 1989-02-14 |
Family
ID=13882095
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP8626982A Granted JPS58204088A (en) | 1982-05-21 | 1982-05-21 | Scintillation detector |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS58204088A (en) |
Families Citing this family (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6117082A (en) * | 1984-07-03 | 1986-01-25 | Toshiba Corp | Radiation detector |
JPS61127670A (en) * | 1984-11-22 | 1986-06-14 | 日立金属株式会社 | Manufacture of sintered body |
US4752424A (en) * | 1986-01-30 | 1988-06-21 | Kabushiki Kaisha Toshiba | Method of manufacturing a rare earth oxysulfide ceramic |
JPS63113387A (en) * | 1986-10-31 | 1988-05-18 | Toshiba Corp | Radiation detector |
JP2696860B2 (en) * | 1987-11-11 | 1998-01-14 | 株式会社日立製作所 | Radiation detection element |
JP2720159B2 (en) * | 1988-01-27 | 1998-02-25 | 株式会社日立メディコ | Multi-element radiation detector and manufacturing method thereof |
JP3194828B2 (en) * | 1993-12-27 | 2001-08-06 | 株式会社東芝 | Sintered phosphor, method of manufacturing the same, radiation detector and X-ray tomography apparatus using the sintered phosphor |
JP3454904B2 (en) * | 1994-02-25 | 2003-10-06 | 株式会社東芝 | Ceramic scintillator and X-ray detector |
US6504156B1 (en) | 1999-07-16 | 2003-01-07 | Kabushiki Kaisha Toshiba | Ceramic scintillator material and manufacturing method thereof, and radiation detector therewith and radiation inspection apparatus therewith |
US7060982B2 (en) | 2003-09-24 | 2006-06-13 | Hokushin Corporation | Fluoride single crystal for detecting radiation, scintillator and radiation detector using the single crystal, and method for detecting radiation |
JP5498908B2 (en) | 2010-09-29 | 2014-05-21 | 株式会社東芝 | Solid scintillator material, solid scintillator, radiation detector and radiation inspection apparatus using the same |
JP6105833B2 (en) * | 2011-04-08 | 2017-03-29 | 株式会社東芝 | X-ray detector and X-ray inspection apparatus |
WO2013136804A1 (en) | 2012-03-15 | 2013-09-19 | 株式会社 東芝 | Solid scintillator, radiation detector and radiographic examination device |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS53129087A (en) * | 1977-04-18 | 1978-11-10 | Jeol Ltd | Scintillation detector |
US4242221A (en) * | 1977-11-21 | 1980-12-30 | General Electric Company | Ceramic-like scintillators |
-
1982
- 1982-05-21 JP JP8626982A patent/JPS58204088A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS58204088A (en) | 1983-11-28 |
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