JP2685867B2 - Method for manufacturing fluorescent ceramics - Google Patents
Method for manufacturing fluorescent ceramicsInfo
- Publication number
- JP2685867B2 JP2685867B2 JP1030732A JP3073289A JP2685867B2 JP 2685867 B2 JP2685867 B2 JP 2685867B2 JP 1030732 A JP1030732 A JP 1030732A JP 3073289 A JP3073289 A JP 3073289A JP 2685867 B2 JP2685867 B2 JP 2685867B2
- Authority
- JP
- Japan
- Prior art keywords
- rare earth
- heat treatment
- scintillator
- light output
- hydrogen
- 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 - Lifetime
Links
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Luminescent Compositions (AREA)
- Measurement Of Radiation (AREA)
Description
【発明の詳細な説明】 ［発明の目的］ （産業上の利用分野） 本発明は、Ｘ線やγ線などの放射線検出器などに用い
られる蛍光性セラミックスの製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for producing a fluorescent ceramic used for a radiation detector for X-rays, γ-rays and the like.
（従来の技術） シンチレータは、Ｘ線などの放射線の刺激によって可
視光または可視光に近い波長の電磁波を放射する材料で
あり、シンチレーションカウンタとしてＸ線CT（Ｘ線断
層像撮影装置）の検出器などに用いられている。(Prior Art) A scintillator is a material that emits visible light or an electromagnetic wave having a wavelength close to visible light by stimulation of radiation such as X-rays, and is a detector of an X-ray CT (X-ray tomography apparatus) as a scintillation counter. It is used for etc.
このようなシンチレータとしては、NaI、CsI、CdWO4
などの単結晶体、BaFCl:Eu、LaOBr:Tb、CsI:Tl、CaWO4
およびCdWO4焼結体（特公昭59−45022号公報参照）、立
方晶系希土類酸化物セラミックス（特開昭59−27283号
公報参照）、Gd2O2S:Pr、Gd2O2S:（Tb,Pr）などの希土
類オキシ硫化物セラミックス（特開昭58−204088号公報
参照）などが知られている。Such scintillators include NaI, CsI, CdWO 4
Single crystal such as BaFCl: Eu, LaOBr: Tb, CsI: Tl, CaWO 4
And CdWO 4 sintered body (see Japanese Patent Publication No. 59-45022), cubic rare earth oxide ceramics (see Japanese Patent Publication No. 59-27283), Gd 2 O 2 S: Pr, Gd 2 O 2 S: Rare earth oxysulfide ceramics such as (Tb, Pr) (see JP-A-58-204088) are known.
これらシンチレータのうち、特に希土類オキシ硫化物
セラミックスは、その高い発光効率や大きなＸ線吸収係
数のためにＸ線CT用のシンチレータとして好適なものと
言える。Among these scintillators, rare earth oxysulfide ceramics are particularly suitable as scintillators for X-ray CT because of their high luminous efficiency and large X-ray absorption coefficient.
上記希土類オキシ硫化物セラミックスは、たとえば原
料粉末をホットプレス法やHIP（熱間静水圧プレス）法
などを用いて焼結させ、このセラミックス焼結体から切
断、研磨などの機械加工によって所望の形状および寸法
にし、シンチレータとして用いられている。The above-mentioned rare earth oxysulfide ceramics are formed into a desired shape by, for example, sintering the raw material powder using a hot pressing method or a HIP (hot isostatic pressing) method, and cutting or polishing the ceramics into a desired shape. And sized and used as a scintillator.
（発明が解決しようとする課題） 上述のように希土類オキシ硫化物セラミックスからな
るシンチレータは、ホットプレスやHIPなどによる焼結
体に切断や研磨などの機械加工を施すことによって得ら
れる。しかし、希土類オキシ硫化物セラミックスは、焼
結の際の印加圧力による残留歪やこれら機械加工による
機械的ダメージによって、継続してＸ線の曝射を受けた
シンチレータが一時的に劣化し、光出力（放射線照射時
にシンチレータから放出される光量）が経時的に低下す
るヒステリシス現象が認められるという問題があった。(Problems to be Solved by the Invention) As described above, the scintillator made of rare earth oxysulfide ceramics is obtained by subjecting a sintered body by hot pressing, HIP, or the like to mechanical processing such as cutting or polishing. However, in rare earth oxysulfide ceramics, the scintillator that has been continuously exposed to X-rays temporarily deteriorates due to residual strain due to the applied pressure during sintering and mechanical damage due to mechanical processing, and the optical output There was a problem that a hysteresis phenomenon was observed in which (the amount of light emitted from the scintillator upon irradiation with radiation) was decreased over time.
このようなヒステリシス現象が生じると、たとえばＸ
線CTのＸ線検出器に用いた際に、誤ったＸ線強度データ
を出力することとなり、雑音の多い画像や誤った画像を
もたらすことになる。また、この光出力は放射線検出器
の感度を決定する重要な特性であり、ヒステリシスを減
少させるために光量が極端に低下するようなことがあっ
てはならない。When such a hysteresis phenomenon occurs, for example, X
When it is used for the X-ray detector of the line CT, it outputs incorrect X-ray intensity data, resulting in a noisy image or an incorrect image. Further, this light output is an important characteristic that determines the sensitivity of the radiation detector, and the light amount must not be extremely reduced in order to reduce the hysteresis.
本発明は、このような従来技術の課題に対処するため
になされたもので、シンチレータの絶対的光出力をほと
んど低下させることなく、放射線の曝射によるヒステリ
シス現象を軽減した蛍光性セラミックスを製造する方法
を提供することを目的としている。The present invention has been made to address such a problem of the conventional technique, and produces a fluorescent ceramic in which the hysteresis phenomenon due to radiation exposure is reduced without substantially reducing the absolute light output of the scintillator. It is intended to provide a way.
［発明の構成］ （課題を解決するための手段） すなわち本発明の蛍光性セラミックスの製造方法は、 化学式:M2O2S ……（Ｉ） （式中、Ｍは希土類元素から選ばれる少なくとも１種の
元素を示す。）で表される希土類オキシ硫化物を主成分
とする希土類元素付活の蛍光性セラミックス焼結体を所
望の形状に機械加工する工程と、この加工体に水素また
は硫化水素と不活性ガスとの混合ガス雰囲気中で800℃
〜1400℃の温度で熱処理を施す工程とを有することを特
徴としている。[Structure of the Invention] (Means for Solving the Problems) That is, the method for producing a fluorescent ceramics of the present invention comprises a chemical formula: M 2 O 2 S (I) (wherein M is at least selected from rare earth elements). One kind of element is shown.) A step of machining a rare earth element-activated fluorescent ceramics sintered body containing a rare earth oxysulfide as a main component into a desired shape, and hydrogen or sulfide on the processed body. 800 ℃ in mixed gas atmosphere of hydrogen and inert gas
And a step of performing heat treatment at a temperature of 1400 ° C.
本発明に用いられる希土類元素付活の蛍光性セラミッ
クス焼結体としては、上記（Ｉ）式で表される希土類オ
キシ硫化物を主成分とするものであり、上記（Ｉ）式中
のＭとしてはGd、La、Ｙ、Luなどが例示され、これらの
１種または２種以上の混合系として用いられる。また、
付活剤としての希土類元素としては、Pr、Tb、Eu、Tmな
どの１種または２種以上が用いられる。具体例として
は、Gd2O2S:Pr、Gd2O2S:（Tb,Pr）、（Y,Gd）2O2S:Pr、
（Y,Gd）2O2S:（Tb,Pr）、La2O2S:Tbなどが例示され
る。これらはたとえばホットプレス法やHIP法などによ
って作製される。The rare earth element-activated fluorescent ceramics sintered body used in the present invention contains a rare earth oxysulfide represented by the above formula (I) as a main component, and M in the above formula (I) is Are exemplified by Gd, La, Y, Lu and the like, and they are used as a mixed system of one kind or two or more kinds thereof. Also,
As the rare earth element as the activator, one kind or two or more kinds of Pr, Tb, Eu, Tm and the like are used. Specific examples include Gd 2 O 2 S: Pr, Gd 2 O 2 S: (Tb, Pr), (Y, Gd) 2 O 2 S: Pr,
Examples include (Y, Gd) 2 O 2 S: (Tb, Pr) and La 2 O 2 S: Tb. These are produced by, for example, the hot pressing method or the HIP method.
本発明においては、これらの希土類元素付活の蛍光性
セラミックス焼結体に対し、所望の形状とするための切
断加工や研磨加工などの機械加工を施し、この後水素ま
たは硫化水素と不活性ガスとの混合ガス雰囲気中で800
℃〜1400℃の温度において熱処理を施す。In the present invention, these rare earth element-activated fluorescent ceramics sintered bodies are subjected to mechanical processing such as cutting and polishing to obtain a desired shape, and then hydrogen or hydrogen sulfide and an inert gas. 800 in a mixed gas atmosphere with
Heat treatment is performed at a temperature of ℃ to 1400 ℃.
この熱処理温度が800℃より低い温度では、有効に内
部歪や機械的ダメーシを取り除くことができず、また14
00℃を超える温度では、上記蛍光性セラミックス焼結体
が着色してしまうという現象がみられ、光出力が低下し
てしまう。At this heat treatment temperature lower than 800 ° C, internal strain and mechanical damage cannot be effectively removed.
At temperatures above 00 ° C., the phenomenon that the fluorescent ceramics sintered body is colored is observed, and the light output is reduced.
また、熱処理の際の雰囲気中の水素または硫化水素の
濃度は１体積％以上であることが好ましい。水素や硫化
水素の濃度が１体積％未満であると光出力の低下が著し
くなるためである。熱処理に要する時間は、温度にも依
存するためいちがいに言えないが、おおよそ10分間以上
で効果が認められ、たとえば１時間〜５時間程度であ
る。Further, the concentration of hydrogen or hydrogen sulfide in the atmosphere during the heat treatment is preferably 1% by volume or more. This is because if the concentration of hydrogen or hydrogen sulfide is less than 1% by volume, the light output will be significantly reduced. The time required for the heat treatment depends on the temperature and cannot be said in any way, but the effect is recognized for about 10 minutes or more, and it is, for example, about 1 to 5 hours.
（作 用） 本発明においては、所望の形状とするための機械加工
を行った希土類オキシ硫化物蛍光性セラミックスに対し
て水素または硫化水素と不活性ガスとの混合ガス雰囲気
中で800℃〜1400℃の温度で熱処理を施す。この水素ま
たは硫化水素を含む不活性ガス中での熱処理によって内
部歪が緩和されるとともに、機械加工による機械的ダメ
ージが有効に取り除かれ、ヒステリシスが低減する。た
とえば上記雰囲気以外の雰囲気中での熱処理では、800
℃〜1400℃の温度範囲による熱処理でも希土類オキシ硫
化物蛍光性セラミックスの着色が発生し、光出力が大幅
に低下してしまう。(Operation) In the present invention, a rare earth oxysulfide fluorescent ceramic machined into a desired shape is treated with hydrogen or a mixed gas atmosphere of hydrogen sulfide and an inert gas at 800 ° C to 1400 ° C. Heat treatment is performed at a temperature of ° C. The heat treatment in an inert gas containing hydrogen or hydrogen sulfide alleviates the internal strain, effectively removes mechanical damage due to machining, and reduces hysteresis. For example, in heat treatment in an atmosphere other than the above, 800
Even in the heat treatment in the temperature range of ℃ to 1400 ℃, the rare earth oxysulfide fluorescent ceramics are colored, and the light output is significantly reduced.
（実施例） 次に、本発明の実施例について説明する。(Example) Next, an example of the present invention is described.
実施例１ まず、1500℃×1000気圧の条件によるHIPによりGd2O2
S:Prのセラミックス焼結体を作製し、このセラミックス
焼結体から1mm×2mm×30mmの大きさのシンチレータ片を
切り出した。Example 1 First, Gd 2 O 2 was prepared by HIP under the conditions of 1500 ° C. and 1000 atm.
A ceramic sintered body of S: Pr was produced, and a scintillator piece having a size of 1 mm × 2 mm × 30 mm was cut out from this ceramic sintered body.
なお、この切断後のシンチレータ片に管電圧120kVp、
線量1500レントゲンのＸ線を曝射し、この後管電圧120k
Vp、線量0.01レントゲンの条件でＸ線を照射して光出力
を測定したところ、切断後のシンチレータ片の光出力に
対して、ヒステリシス現象によりＸ線曝射前の81％に低
下した。In addition, the tube voltage 120 kVp on the scintillator piece after this cutting,
X-rays with a dose of 1500 roentgens were irradiated, and then the tube voltage was 120k.
When the light output was measured by irradiating X-rays under the condition of Vp and a dose of 0.01 roentgen, the light output of the scintillator piece after cutting was lowered to 81% before the X-ray exposure due to the hysteresis phenomenon.
次に、切断して所望の形状としたシンチレータ片に、
箱型電気炉中において水素と窒素の混合ガス（水素濃度
３体積％、流量100/min）雰囲気下で1200℃×２時間
の条件で熱処理を施した。Next, on the scintillator piece cut into a desired shape,
The heat treatment was performed in a box-type electric furnace in a mixed gas of hydrogen and nitrogen (hydrogen concentration: 3% by volume, flow rate: 100 / min) at 1200 ° C. for 2 hours.
このようにして得た熱処理後のシンチレータに線量15
00レントゲンのＸ線を曝射し、この後管電圧120kVp、線
量0.01レントゲンの条件でＸ線を照射し、Ｘ線曝射前の
シンチレータ片の光出力を100％として光出力を測定し
たところ、光出力の維持率は85％と、上記熱処理を行わ
ないものに比べてヒステリシスが減少した。また、熱処
理後のシンチレータの光出力は、熱処理を施さないもの
に対して14％向上していた。The heat-treated scintillator thus obtained had a dose of 15
After irradiating X-ray of 00 roentgen, and then irradiating with X-ray under the condition of tube voltage 120kVp and dose of 0.01 roentgen, the light output of the scintillator piece before X-ray irradiation was measured as 100%, and the light output was measured. The light output maintenance rate was 85%, which was smaller than that in the case without the above heat treatment. In addition, the light output of the scintillator after heat treatment was improved by 14% as compared with that without heat treatment.
実施例２ 上記実施例１における熱処理に代えて、切断後のシン
チレータ片に管状炉中で硫化水素と窒素の混合ガス（硫
化水素濃度２体積％、流量２/min）雰囲気下で900℃
×１時間の熱処理を施した。Example 2 Instead of the heat treatment in Example 1, the scintillator piece after cutting was heated to 900 ° C. in a tubular furnace in a mixed gas of hydrogen sulfide and nitrogen (hydrogen sulfide concentration 2% by volume, flow rate 2 / min).
× Heat treatment was performed for 1 hour.
このようにして得たシンチレータに対して実施例１と
同様に、線量1500レントゲンのＸ線曝射を行い、光出力
の維持率を測定したところ、91％と熱処理を施さないも
のに比べてヒステリシスの大幅な減少が認められた。ま
た、処理後のシンチレータの光出力は、熱処理前に比べ
てわずか１％低下しただけであり、実用上ほとんど支障
のないものであった。The scintillator thus obtained was irradiated with X-rays at a dose of 1500 roentgens in the same manner as in Example 1, and the light output maintenance rate was measured. Was significantly reduced. Further, the light output of the scintillator after the treatment was reduced by only 1% as compared with that before the heat treatment, which was practically no problem.
実施例３ 1400℃×1000気圧の条件のHIPによって作製したLa2O2
S:Tbのセラミックス焼結体から1mm×2mm×30mmの大きさ
のシンチレータ片を切り出した。Example 3 La 2 O 2 prepared by HIP under the condition of 1400 ° C. × 1000 atm
A scintillator piece measuring 1 mm x 2 mm x 30 mm was cut out from the S: Tb ceramics sintered body.
なお、この切断後のシンチレータ片に実施例１と同一
条件でＸ線を曝射し、この後実施例１と同様にして光出
力の維持率を測定したところ、ヒステリシス現象により
Ｘ線曝射前の89％に低下した。The scintillator piece after the cutting was exposed to X-rays under the same conditions as in Example 1, and the light output retention rate was measured in the same manner as in Example 1. As a result, a hysteresis phenomenon was observed before X-ray irradiation. Fell to 89%.
次に、切断して所望の形状としたシンチレータ片に、
箱型電気炉中において水素と窒素の混合ガス（水素濃度
３体積％、流量100/min）雰囲気下で1200℃×１時間
の条件で熱処理を施した。Next, on the scintillator piece cut into a desired shape,
The heat treatment was performed in a box-type electric furnace in a mixed gas of hydrogen and nitrogen (hydrogen concentration: 3% by volume, flow rate: 100 / min) at 1200 ° C. for 1 hour.
このようにして得た熱処理後のシンチレータに線量15
00レントゲンのＸ線を曝射し、実施例１と同様にして光
出力の維持率を測定したところ94％と、上記熱処理を行
わないものに比べてヒステリシスが大幅に減少した。ま
た、熱処理後のシンチレータの光出力は、熱処理を施さ
ないものに対して10％向上していた。The heat-treated scintillator thus obtained had a dose of 15
When the X-ray of 00 roentgen was irradiated and the light output retention rate was measured in the same manner as in Example 1, it was 94%, and the hysteresis was significantly reduced as compared with the case where the heat treatment was not performed. In addition, the light output of the scintillator after heat treatment was improved by 10% as compared with that without heat treatment.
［発明の効果］ 以上説明したように本発明によれば、所望の形状を得
る際に不可欠な機械加工によって受けるダメージや焼結
時の印加圧力による残留歪に起因するヒステリシス現
象、すなわちＸ線曝射による光出力の低下を大幅に減少
させることが可能となる。しかも、熱処理による絶対的
光出力の低下がほとんどないために、十分な検出感度が
得られる。したがって、本発明によって得られる蛍光性
セラミックスは十分な感度と少ないヒステリシスを示
し、Ｘ線CTなどの放射線検出器に好適なものを提供する
ことができる。[Effects of the Invention] As described above, according to the present invention, the hysteresis phenomenon, that is, the X-ray exposure, which is caused by the damage which is inevitable by the machining for obtaining the desired shape and the residual strain due to the applied pressure at the time of sintering. It is possible to significantly reduce the decrease in the light output due to the irradiation. Moreover, since the absolute light output is hardly reduced by the heat treatment, sufficient detection sensitivity can be obtained. Therefore, the fluorescent ceramic obtained by the present invention exhibits sufficient sensitivity and little hysteresis, and can be provided as a suitable radiation detector for X-ray CT and the like.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 豊島 正規 神奈川県横浜市磯子区新杉田町８ 株式 会社東芝横浜事業所内 (56)参考文献 特開 平２−173088（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Teshima Teshima 8 Shin-Sugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Toshiba Corporation Yokohama Works (56) References JP-A-2-173088 (JP, A)
Claims (1)
元素を示す。）で表される希土類オキシ硫化物を主成分
とする希土類元素付活の蛍光性セラミックス焼結体を所
望の形状に機械加工する工程と、この加工体に水素また
は硫化水素と不活性ガスとの混合ガス雰囲気中で800℃
〜1400℃の温度で熱処理を施す工程とを有することを特
徴とする蛍光性セラミックスの製造方法。1. A rare earth element-activating compound containing a rare earth oxysulfide as a main component represented by the chemical formula: M 2 O 2 S (wherein M represents at least one element selected from rare earth elements). The process of machining the fluorescent ceramics sintered body into a desired shape, and this processed body in a mixed gas atmosphere of hydrogen or hydrogen sulfide and an inert gas at 800 ° C.
A step of performing a heat treatment at a temperature of 1400 ° C. to 1400 ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1030732A JP2685867B2 (en) | 1989-02-09 | 1989-02-09 | Method for manufacturing fluorescent ceramics |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1030732A JP2685867B2 (en) | 1989-02-09 | 1989-02-09 | Method for manufacturing fluorescent ceramics |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02209987A JPH02209987A (en) | 1990-08-21 |
| JP2685867B2 true JP2685867B2 (en) | 1997-12-03 |
Family
ID=12311845
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1030732A Expired - Lifetime JP2685867B2 (en) | 1989-02-09 | 1989-02-09 | Method for manufacturing fluorescent ceramics |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2685867B2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4402258C2 (en) * | 1994-01-26 | 1996-06-20 | Siemens Ag | Fluorescent with reduced afterglow |
| DE4402260A1 (en) * | 1994-01-26 | 1995-07-27 | Siemens Ag | Prodn. of phosphor ceramic |
| JP3454904B2 (en) * | 1994-02-25 | 2003-10-06 | 株式会社東芝 | Ceramic scintillator and X-ray detector |
| FR2721918B1 (en) * | 1994-06-29 | 1996-09-06 | Rhone Poulenc Chimie | RARE EARTH OXYSULFIDE, PREPARATION METHOD THEREOF, AND USE THEREOF AS LUMINOPHORE |
| DE4425922B4 (en) * | 1994-07-21 | 2004-03-18 | Siemens Ag | Process for producing a phosphor ceramic by hot pressing |
| US8137587B2 (en) | 2009-02-19 | 2012-03-20 | Nitto Denko Corporation | Method of manufacturing phosphor translucent ceramics and light emitting devices |
| US8123981B2 (en) | 2009-02-19 | 2012-02-28 | Nitto Denko Corporation | Method of fabricating translucent phosphor ceramics |
| CN115321579B (en) * | 2022-08-18 | 2023-08-08 | 北京科技大学 | Preparation method of high-performance oxysulfide fluorescent powder |
-
1989
- 1989-02-09 JP JP1030732A patent/JP2685867B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02209987A (en) | 1990-08-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Lempicki et al. | A new lutetia-based ceramic scintillator for X-ray imaging | |
| EP0297269B1 (en) | Solid state scintillator and method for preparing such scintillator | |
| US4242221A (en) | Ceramic-like scintillators | |
| RU2755268C2 (en) | Transparent ceramic scintillation detector with garnet structure for positron emission tomography | |
| JP5281742B2 (en) | Scintillator material and radiation detector containing scintillator material | |
| JP5675339B2 (en) | Solid scintillator, radiation detector, and X-ray tomography apparatus | |
| US20060043335A1 (en) | Doped cadmium tungstate scintillator with improved radiation hardness | |
| Köstler et al. | Effect of Pr-codoping on the X-ray induced afterglow of (Y, Gd) 2O3: Eu | |
| JP3454904B2 (en) | Ceramic scintillator and X-ray detector | |
| JP3194828B2 (en) | Sintered phosphor, method of manufacturing the same, radiation detector and X-ray tomography apparatus using the sintered phosphor | |
| JP2685867B2 (en) | Method for manufacturing fluorescent ceramics | |
| JP2002275465A (en) | Ceramic scintillator and method for producing the same, and radioactive ray detector and radioactive ray- surveying instrument by using the same | |
| US7060982B2 (en) | Fluoride single crystal for detecting radiation, scintillator and radiation detector using the single crystal, and method for detecting radiation | |
| CN112028493B (en) | Preparation method and application of high-transparency all-inorganic perovskite quantum dot glass scintillator | |
| JP3260541B2 (en) | Phosphor powder, ceramic scintillator and method for producing the same | |
| JP2002082171A (en) | Radiation detector and x-ray diagnostic equipment using the same | |
| Kato et al. | TSL and OSL properties of undoped and Eu-doped NaMgF3 translucent ceramics prepared by a spark plasma sintering method | |
| JP3246781B2 (en) | Ceramic scintillator and method of manufacturing the same | |
| JP4905756B2 (en) | Fluoride single crystal and scintillator for radiation detection and radiation detector | |
| JPH02212586A (en) | Manufacture of florescent ceramic | |
| JP2989089B2 (en) | Ceramic scintillator material | |
| JPS6318286A (en) | Radiation detector | |
| Su et al. | Rare earth ions in advanced X-ray imaging materials | |
| Silva et al. | Development of nano-sized α-Al 2 O 3: C films for application in digital radiology | |
| Cusano et al. | Scintillators |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20070815 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080815 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090815 Year of fee payment: 12 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090815 Year of fee payment: 12 |