2019 Fiscal Year Annual Research Report
Material Survey of Novel Red-hot Scintillators
Project/Area Number |
19H02422
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Research Institution | Tohoku University |
Principal Investigator |
黒澤 俊介 東北大学, 未来科学技術共同研究センター, 准教授 (80613637)
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Co-Investigator(Kenkyū-buntansha) |
北浦 守 山形大学, 理学部, 教授 (60300571)
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Project Period (FY) |
2019-04-01 – 2022-03-31
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Keywords | シンチレータ / 赤色発光 |
Outline of Annual Research Achievements |
放射線の入射によって発光する、高機能発光材料であるシンチレータについて、いままでの発光領域とは異なる赤色~近赤外線で発光する新しいシンチレータの開発を行った。具体的には、塩化物、臭化物といったハロゲン化物、および、酸化物を中心に、発光波長600 nm~1100nm程度の赤色~近赤外線のシンチレータをブリッジマン法やマイクロ引き下げ法などを利用して育成を行った。 育成後には、結晶が正しく育成されているか、結晶構造や組成の分析を行った。さらに研磨などの加工を行った後に、目的の発光波長(600 nm~1100nm程度)に合致するか確認した。さらに、1ガンマ線光子入射で変換されるシンチレータ光子数(発光量)をシングルフォトンカウンティング法で確認したところ、ヨウ化物で発光波長700nm、発光量50,000光子/MeV以上と目標値の新しい材料を見つけることができた。 開発したシンチレータについては、新しい材料であるため、その結晶構造の解明も進めて、発光のメカニズムと結晶構造の関連性について、調査を進めた。たとえば、ある結晶については、Hfなどの金属元素の周りをヨウ素が6個配置した八面体構造をとることが分かっており、この八面体構造が赤色の発光を発現させることが示唆されている。 赤色発光シンチレータの利点として、チェレンコフ発光などの青色発光との切り分けができるため、チェレンコフ発光などの青色発光がノイズとなるような放射線計測の現場で利用する点がある。そこで、このような応用、特に線量の高い領域での測定など、新しい検出器への搭載に向けた、結晶の加工などについても研究を進めることができた。
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Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
当初計画を前倒して、当該年度中・期間中に、目標の発光波長と発光量を持ち、かつ、蛍光寿命も早い理想的なシンチレータを見つけることができたため。
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Strategy for Future Research Activity |
引き続き、組成の設計計画に基づき、さらに適切な発光波長の中で、より高い発光量を示す新規シンチレータの開発を行う。さらに、見つけた新規材料について、発光の起源がまだ特定されていないことから、材料設計指針の精度をさらに高める目的も含めて、その特定を進める。そのために、発光強度の温度依存性などを10ケルビン程度の低温から常温・高温まで測定し、そのふるまいから発光起源について議論する。
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[Presentation] Development of the new radiation monitor system using a novel scintillator2019
Author(s)
Shunsuke Kurosawa, Shohei Kodama, Takahiko Horiai, Akihiro Yamaji, Rikito Murakami, Yasuhiro Shoji, Masao Yoshino, Yuji Ohashi, Kei Kamada, Yuui Yokota, Akira Yoshikawa
Organizer
International Topical Workshop on Fukushima Decommissioning Research (FDR2019)
Int'l Joint Research
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[Presentation] Crystal growth and optical properties of a Ce2Si2O7 single crystal2019
Author(s)
Takahiro Horiai, Shunsuke Kurosawa, Rikito Murakami, Yasuhiro Shoji, Jan Pejchal, Masao Yoshino, Akihiro Yamaji, Hiroki Sato, Yuji Ohashi, Kei Kamada, Yuui Yokota, Akira Yoshikawa
Organizer
19th International Conference on Crystal Growth and Epitaxy (ICCGE-29)
Int'l Joint Research
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[Presentation] Optical Study on Garnet-Type Scintillator with Longer-Wave-Emitting2019
Author(s)
Shunsuke KUROSAWA, Akihiro YAMAJI, Shohei KODAMA, Shinnosuke YAMATO, Yutaro KURASHIMA, Kei KAMADA, Masao YOSHINO, Satoshi TOYODA, Hiroki SATO, Yuui YOKOTA, Yuji Ohashi, Akira YOSHIKAWA
Organizer
8th International Workshop on Photoluminescence in Rare Earths: Photonic Materials and Devices (PRE'19)
Int'l Joint Research
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[Presentation] Development of Cr-Doped Oxide Crystals as Red and Near Infra-Red Emission for Medical Use2019
Author(s)
S. Kurosawa, T. Shishido, T. Sugawara, A. Nomura, K. Yubuta, A. Yamaji, M.Yoshino, S. Toyoda, H. Sato, Y. Ohashi, K. Kamada, Y. Yokota, A. Yoshikawa
Organizer
International Conference on Excited States of Transitions Elements
Int'l Joint Research
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[Presentation] Self-Trapped Exciton Luminescence of Anion-Substituted Cesium Hafnium Chloride2019
Author(s)
S. Kodama, S. Kurosawa, M. Ohno, A. Yamaji, M. Yoshino, S. Toyoda, H. Sato, Y. Ohashi, K. Kamada, Y. Yokota, R. Kral, J. Pejchal, M. Nikl, A. Yoshikawa
Organizer
International Conference on Excited States of Transitions Elements
Int'l Joint Research
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[Presentation] Development of La-GPS(Ce) Pixel Scintillation Arrays for Real-Time Dose-Verification in Particle Therapy2019
Author(s)
Shunsuke Kurosawa, Yasuhiro Shoji, Shinya Sonoda, Tetsuya Mizumumo, Masao Yoshino, Hayato Numakura, Mitsuru Abe, Atsushi Takada, Akihiro. Yamaji, Yuji Ohashi, Yuui Yokota, Kei Kamada, Akira Yoshikawa, Fuyuki Tokanai, Takeo Iwai, Kenji Nemoto And Toru Tanimori
Organizer
15th International conference on Scintillating Materials and their Applications (SCINT2019)
Int'l Joint Research
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[Presentation] Development of the Fiber-reading Scintillation Detector under Ultra-high Dose Rate2019
Author(s)
Shohei Kodama, Shunsuke Kurosawa, Maki Ohno, Ai Makabe, Yuki Morishita, Hiroshi Usami, Masateru Hayashi, Hiroki Tanaka, Vladimir Kochurikhin, Akihiro Yamaji, Masao Yoshino, Hiroki Sato, Yuji Ohashi, Kei Kamada, Yuui Yokota, Akira Yoshikawa
Organizer
15th International conference on Scintillating Materials and their Applications (SCINT2019)
Int'l Joint Research
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[Presentation] Synthesis and optical properties of red-emitting A2MI6 scintillators (A = K, Rb and Cs, M = Zr and Hf)2019
Author(s)
Shohei Kodama, Shunsuke Kurosawa, Maki Ohno, Akihiro Yamaji, Masao Yoshino, Hiroki Sato, Yuji Ohashi, Kei Kamada, Yuui Yokota, Akira Yoshikawa
Organizer
The 13th Pacific Rim Conference of Ceramic Societies (PACRIM13)
Int'l Joint Research
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[Presentation] Novel material-search method for transparent optical materials with high melting point using electric arc2019
Author(s)
Yutaro.Kurashima, Shunsuke Kurosawa, Rikito Murakami, Akihiro Yamaji, Kei Kamada, Masao Yoshino, Satoshi Toyoda, Hiroki Sato, Yuui Yokota, Yuji Ohashi, Akira Yoshikawa
Organizer
The 13th Pacific Rim Conference of Ceramic Societies (PACRIM13)
Int'l Joint Research
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[Presentation] Study on Red-Emission Scintillation Materials ~Crystals & powders~2019
Author(s)
Shunsuke Kurosawa, Yutaro Kurashima, Akihiro Yamaji, Shohei Kodama, Masao Yoshino, Satoshi Toyoda, Hiroki Sato, Yuui Yokota, Kei Kamada, Yuji Ohashi, Akira Yoshikawa
Organizer
The 13th Pacific Rim Conference of Ceramic Societies (PACRIM13)
Int'l Joint Research / Invited
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[Presentation] Direction-Sensitive Dark Matter Search using Zinc Tungstate Scintillators2019
Author(s)
S. Kurosawa, H. Sekiya, A. Yamaji, M. Abe, M. Tsukahara, T. Horiai, R. Murakami, Y. Shoji, M. Yoshino, H. Sato, Y. Ohashi, Y. Yokota, K. Kamada, A. Yoshikawa
Organizer
2019 IEEE Nuclear Science Symposium and Medical Imaging Conference
Int'l Joint Research
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[Presentation] Growth of Ce-doped (Gd,La)2 Si2O7 Single Crystals and their applications2019
Author(s)
Y. Shoji, S. Kurosawa, V. Kochurikhin, K. Kamada, S. Hayasaka, M. Yoshino, Y. Yokota, Y. Ohashi, A. Yamaji, A. Yoshikawa
Organizer
2019 IEEE Nuclear Science Symposium and Medical Imaging Conference
Int'l Joint Research
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[Presentation] Development of an Electron-Tracking Compton Camera and Novel Scintillator for In-Beam Dose-Verification in Particle Therapy2019
Author(s)
S. Kurosawa, S. Sonoda, T. Mizumoto, H. Numakura, M. Yoshino, S. Komura, H. Abe, A. Takada, A. Yamaji, Y. Ohashi, H. Sato, K. Kamada, Y. Yokota, A. Yoshikawa, F. Tokanai, T. Iwai, K. Nemoto, T. Tanimori
Organizer
2019 IEEE Nuclear Science Symposium and Medical Imaging Conference
Int'l Joint Research
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[Presentation] Real-Time Dose-Verification in Particle Therapy Using an Electron-Tracking Compton Camera and their simulation study2019
Author(s)
Shunsuke Kurosawa, Yasuhiro Shoji, Shinya Sonoda, Tetsuya Mizumoto, Masao Yoshino, Hayato Numakura, Shotaro Komura, Mitsuru Abe, Atsushi Takada, Akihiro Yamaji, Yuji Ohashi, Yuui Yokota, Kei Kamada, Akira Yoshikawa, Fuyuki Tokanai, Takeo Iwai, Kenji Nemoto and Toru Tanimori
Organizer
the 1st Annual Conference of the Particle Therapy Co-operative Group Asia-Oceania (PTCOG-AO’19)
Int'l Joint Research
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