Scintillator and method for manufacturing the same, radiation detector, and radiation inspection apparatus

JP7873422B2Active Publication Date: 2026-06-12NAT INST FOR MATERIALS SCI +1
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Patent Information

Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
NAT INST FOR MATERIALS SCI
Filing Date
2023-11-07
Publication Date
2026-06-12

AI Technical Summary

Benefits of technology

【0012】 本発明によれば、結晶中の散乱中心が少なく、シンチレーション特性が改善されたシンチレータ、およびその製造方法が提供される。本発明のシンチレータは、実用に耐え得る程度に高い発光量を示すため、放射線検出器用のシンチレータとして、特に、熱中性子検出器用のシンチレータとして用いるのに好適である。また、本発明のシンチレータを備える放射線検出器は、放射線検査装置に好適に用いることができる。

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Abstract

The present invention provides a scintillator in which there are a reduced number of scattering centers in a crystal and scintillation properties are improved. The scintillator according to one embodiment of the present invention comprises a single crystal which contains Ce, Li, Y, B and O, optionally contains an A element (wherein the A element comprises at least one element selected from the group consisting of Na, K, Cs and Rb), an RE element (wherein the RE element comprises one or two or more elements selected from rare earth elements other than Ce and Y) and an M element (wherein the M element comprises at least one element selected from the group consisting of Mg, Ca, Sr and Ba), and is represented by general formula (Li1-xAx)6[(Y1-yREy)(1-z-p)CezMp)]B3O9-p / 2 (wherein 0 ≤ x < 1, 0 ≤ y ≤ 1, 0 < z ≤ 0.06, 0 ≤ p ≤ 0.001), in which the density of scattering centers on a cross-sectional surface of the scintillator is less than 2×108 / cm2.
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Claims

1. It contains cerium (Ce), lithium (Li), yttrium (Y), boron (B), oxygen (O), and optionally, element A (element A is selected from the group consisting of sodium (Na), potassium (K), cesium (Cs), and rubidium (Rb)), element RE (element RE is one or more of the rare earth elements other than cerium (Ce) and yttrium (Y)), and element M (element M is selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba)), General formula (Li １－ｘ A ｘ ) ６ [(Y １－ｙ RE ｙ ) （１－ｚ－ｐ） Ce ｚ M ｐ )]B ３ O ９－ｐ／２ (where 0 ≤ x < 1, 0 ≤ y ≤ 1, 0 < z ≤ 0.06, 0 ≤ p ≤ 0.001), and composed of a single crystal represented by In the cross-section, the density of scattering centers is 2 × 10⁻⁶ ８ pieces / cm ２ It is less than, A scintillator with a light emission of 4000 ph / n or more.

2. The aforementioned scattering center density is 1 × 10⁻⁶ ８ pieces / cm ２ The scintillator according to claim 1, wherein the value is less than [value missing].

3. The aforementioned scattering center density is 8 × 10 ７ pieces / cm ２ The scintillator according to claim 2, which is as follows:

4. The aforementioned scattering center density is 5 × 10 ７ pieces / cm ２ The scintillator according to claim 3, which is as follows:

5. The scintillator according to claim 1, wherein z in the general formula is 0 < z ≤ 0.

01.

6. The scintillator according to claim 5, wherein z in the general formula is 0 < z ≤ 0.

005.

7. The scintillator according to claim 1, wherein the decay time is 40 ns or less.

8. The scintillator according to claim 1, wherein the afterglow is 0.1% or less.

9. The scintillator according to claim 1, wherein the single crystal has a crystal structure belonging to the P21 / c space group.

10. A material comprising cerium (Ce), lithium (Li), yttrium (Y), boron (B), oxygen (O), and optionally, element A (element A is selected from the group consisting of sodium (Na), potassium (K), cesium (Cs), and rubidium (Rb)), element RE (element RE is one or more of the rare earth elements other than cerium (Ce) and yttrium (Y)), and element M (element M is selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba), It consists of a single crystal represented by the general formula (Li 1-x A x) 6 [(Y 1-y RE y) (1-z-p) Ce z M p)]B 3 O 9-p / 2 (where 0 ≤ x < 1, 0 ≤ y ≤ 1, 0 < z ≤ 0.01, 0 ≤ p ≤ 0.001), A scintillator in which the density of scattering centers in a cross-section is less than 2 × 10⁸ centers / cm².

11. To prepare raw materials containing cerium (Ce), lithium (Li), yttrium (Y), boron (B), oxygen (O), and optionally, element A (element A is selected from the group consisting of sodium (Na), potassium (K), cesium (Cs), and rubidium (Rb)), element RE (element RE is one or more of the rare earth elements other than cerium (Ce) and yttrium (Y)), and element M (element M is selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba)), The aforementioned raw materials are melted and single crystals are grown by the pulling method, The single crystal is heat-treated in an oxygen-containing atmosphere at a temperature of 100°C or higher and below the melting point of the single crystal. It includes, It contains cerium (Ce), lithium (Li), yttrium (Y), boron (B), oxygen (O), and optionally, element A (element A is selected from the group consisting of sodium (Na), potassium (K), cesium (Cs), and rubidium (Rb)), element RE (element RE is one or more of the rare earth elements other than cerium (Ce) and yttrium (Y)), and element M (element M is selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba)), It consists of a single crystal represented by the general formula (Li 1-x A x) 6 [(Y 1-y RE y) (1-z-p) Ce z M p)]B 3 O 9-p / 2 (where 0 ≤ x < 1, 0 ≤ y ≤ 1, 0 < z ≤ 0.06, 0 ≤ p ≤ 0.001), A method for manufacturing a scintillator in which the density of scattering centers in a cross-section is less than 2 × 10⁸ centers / cm².

12. The method according to claim 11, wherein the heat treatment is performed by heat-treating the single crystal in air at a temperature range of 500°C to 850°C.

13. The method according to claim 12, wherein the heat treatment is performed by heat-treating the single crystal in air at a temperature range of 800°C to 840°C.

14. The preparation of the aforementioned raw materials is done using the general formula (Li １－ｘ A ｘ ) ６ [(Y １－ｙ RE ｙ ) （１－ｚ－ｐ） Ce ｚ M ｐ ) ] B ３ O ９－ｐ／２ The method according to claim 11, wherein the raw materials are prepared to satisfy the composition of 0 ≤ x < 1, 0 ≤ y ≤ 1, 0 < z ≤ 0.06, and 0 ≤ p ≤ 0.

001.

15. The aforementioned raw material is CeF ３ or CEO ２ The method according to claim 11, comprising:

16. The aforementioned raw materials include at least, Li ２ O, LiOH, Li ２ CO ３ , and Li ２ B ４ O ７ A lithium source selected from the group consisting of, Y ２ O ３ The yttrium source is, B ２ O ３ , H ３ BO ３ , and Li ２ B ４ O ７ A boron source selected from the group consisting of, CeF ３ , and, CEO ２ A cerium source selected from the group consisting of at least one such source and The method according to claim 11, comprising:

17. The aforementioned raw material is of the general formula (Li １－ｘ A ｘ ) ６ [(Y １－ｙ RE ｙ ) （１－ｚ－ｐ） Ce ｚ M ｐ ) ] B ３ O ９－ｐ／２ The method according to claim 16, wherein the boron source is contained in an excess of 1 mol% to 5 mol% with respect to 0 ≤ x < 1, 0 ≤ y ≤ 1, 0 < z ≤ 0.06, and 0 ≤ p ≤ 0.

001.

18. A scintillator according to any one of claims 1 to 10, A photoelectric converter that detects light from the scintillator and converts it into an electrical signal, A radiation detector equipped with the following features.

19. A radiation source that irradiates the subject with radiation, A radiation detector according to claim 18, which detects radiation that penetrates the subject, A radiation inspection device equipped with the following features.