Development of fast-type GAGG scintillator for realizing higher performance PET system

2018 Fiscal Year Annual Research Report

• Project/Area Number: 16H05986
• Research Institution: Tohoku University
• Principal Investigator: 鎌田 圭 東北大学, 未来科学技術共同研究センター, 准教授 (60639649)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: シンチレータ / 放射線検出器 / 単結晶成長 / 医療画像装置

Outline of Annual Research Achievements

1インチサイズでのLi、Mg、Ceに関し各共添加仕込み濃度における結晶作製を行い、シンチレータ特性と各種元素の共添加量との相関関係を検討するとともにシンチレータ特性の改善メカニズムに関する検討を行った。陽イオン欠陥に起因する酸素欠陥が発光量の低下や蛍光寿命の長寿命化に影響するというメカニズムを見出すとともに、組成最適化に加え結晶自体の品質向上を達成した結果、発光量48,000photon/MeV以上を満足しつつ、蛍光寿命36ns、時間分解能160psとなる組成を見出した。
当該結晶組成において、大型単結晶作製技術の開発を進め、断熱材配置条件の検討による温度勾配の調整に加え、コイル位置、育成雰囲気、回転数の最適化を行った。加えて、冷却条件の検討及び結晶制御プログラムの開発により、形状制御された3３インチ径×100mm長さの結晶の安定的な作製が可能となった。３インチ径高速型GAGG単結晶の連続育成を行い、育成回数ごとの発光量・蛍光寿命を測定した。これまでに3回分の連続生産を行い、連続生産3回目においてリチャージ5回までの特性変動が10％以内であることを確認した。
PET装置に搭載するため、高速型GAGGシンチレータアレーを試作した。古河シンチテックの協力を受け、試作した高速型GAGGシンチレータアレーを用いて搭載試験を実施した。結果として、既存のPET装置の解像度2mmを上回る0.98mmの解像度を達成した。感度についても測定を行った結果、PET装置としての感度1.31％を達成した。

Research Progress Status

平成30年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

平成30年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] Physics AS CR(チェコ)
  • Country Name: CZECH
  • Counterpart Institution: Physics AS CR
• [Int'l Joint Research] ソウル大学(韓国)
  • Country Name: KOREA (REP. OF KOREA)
  • Counterpart Institution: ソウル大学
• [Journal Article] Development of a high resolution LaGPS imaging detector with pulse shape discrimination capability of different types of radiations (2019)
  • Author(s): Yamamoto Seiichi、Kamada Kei、Kurosawa Shunsuke、Yoshikawa Akira
  • Journal Title: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Volume: 922 Pages: 8～18
  • DOI: 10.1016/j.nima.2018.11.056
  • Peer Reviewed / Open Access
• [Journal Article] Comprehensive Study on Ce-Doped (Gd, La)2Si2O7 Scintillator (2018)
  • Author(s): Kurosawa Shunsuke、Horiai Takahiko、Murakami Rikito、Shoji Yasuhiro、Jan Pejchal、Yamaji Akihiro、Kodama Shohei、Ohashi Yuji、Yokota Yuui、Kamada Kei、Yoshikawa Akira、Ohnishi Akimasa、Kitaura Mamoru
  • Journal Title: IEEE Transactions on Nuclear Science Volume: 65 Pages: 2136～2139
  • DOI: 10.1109/TNS.2018.2841917
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Crystal structure of Ce-doped (La,Gd)2Si2O7 grown by the Czochralski process (2018)
  • Author(s): Murakami Rikito、Kurosawa Shunsuke、Yamane Hisanori、Horiai Takahiko、Shoji Yasuhiro、Yokota Yuui、Yamaji Akihiro、Ohashi Yuji、Kamada Kei、Yoshikawa Akira
  • Journal Title: Journal of Alloys and Compounds Volume: 748 Pages: 404～410
  • DOI: 10.1016/j.jallcom.2018.02.286
  • Peer Reviewed
• [Journal Article] Growth and luminescent properties of Ce and Eu doped Cesium Hafnium Iodide single crystalline scintillators (2018)
  • Author(s): Kodama Shohei、Kurosawa Shunsuke、Yamaji Akihiro、Pejchal Jan、Kr?l Robert、Ohashi Yuji、Kamada Kei、Yokota Yuui、Nikl Martin、Yoshikawa Akira
  • Journal Title: Journal of Crystal Growth Volume: 492 Pages: 1～5
  • DOI: 10.1016/j.jcrysgro.2018.03.033
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Crystal Growth and Optical Properties of Organic Crystals for Neutron Scintillators (2018)
  • Author(s): YAMAJI Akihiro、KUROSAWA Shunsuke、OHASHI Yuji、YOKOTA Yuui、KAMADA Kei、YOSHIKAWA Akira
  • Journal Title: Plasma and Fusion Research Volume: 13 Pages: 2405011～2405011
  • DOI: 10.1585/pfr.13.2405011
  • Peer Reviewed
• [Journal Article] Growth and Scintillation Properties of Two-Inch-Diameter SrI2(Eu) Single Crystals (2018)
  • Author(s): Shoji Yasuhiro、Kurosawa Shunsuke、Yokota Yuui、Hayasaka Shoki、Kamada Kei、Yoshino Masao、Yamaji Akihiro、Chani Valery、Ohashi Yuji、Sakuragi Shiro、Yoshikawa Akira
  • Journal Title: Crystal Growth & Design Volume: 18 Pages: 3747～3752
  • DOI: 10.1021/acs.cgd.7b01044
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Crystal growth, optical properties, and scintillation responses of Pr-doped CeBr3 single crystals (2018)
  • Author(s): Yokota Yuui、Ito Tomoki、Yoshino Masao、Yamaji Akihiro、Ohashi Yuji、Kurosawa Shunsuke、Kamada Kei、Yoshikawa Akira
  • Journal Title: Japanese Journal of Applied Physics Volume: 57 Pages: 070312～070312
  • DOI: 10.7567/JJAP.57.070312
  • Peer Reviewed
• [Journal Article] Growth and characterization of directionally solidified eutectic systems for scintillator applications (2018)
  • Author(s): Yoshikawa Akira、Kamada Kei、Kurosawa Shunsuke、Yokota Yuui、Yamaji Akihiro、Chani Valery I.、Ohashi Yuji、Yoshino Masao
  • Journal Title: Journal of Crystal Growth Volume: 498 Pages: 170～178
  • DOI: 10.1016/j.jcrysgro.2018.02.032
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Optimization of Dopants and Scintillation Fibers’ Diameter of GdAlO3/<inline-formula> <tex-math notation="LaTeX">$\alpha$ </tex-math> </inline-formula>-Al2O3 Eutectic for High-Resolution X-Ray Imaging (2018)
  • Author(s): Kamada Kei、Yasui Nobuhiro、Ohashi Yoshihiro、Den Toru、Yamaguchi Hiroaki、Yamaji Akihiro、Shoji Yasuhiro、Yoshisno Masao、JinKim Kyoung、Kurosawa Shunsuke、Ohashi Yuji、Yokota Yuui、Yoshikawa Akira
  • Journal Title: IEEE Transactions on Nuclear Science Volume: 65 Pages: 2036～2040
  • DOI: 10.1109/TNS.2018.2841026
  • Peer Reviewed
• [Journal Article] Single crystal growth of submillimeter diameter sapphire tube by the micro-pulling down method (2018)
  • Author(s): Kamada Kei、Murakami Rikito、Kochurikhin Vladimir V.、Luidmila Gushchina、Jin Kim Kyoung、Shoji Yasuhiro、Yamaji Akihiro、Kurosawa Shunsuke、Ohashi Yuji、Yokota Yuui、Yoshikawa Akira
  • Journal Title: Journal of Crystal Growth Volume: 492 Pages: 45～49
  • DOI: 10.1016/j.jcrysgro.2018.03.023
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Phase formation and crystal growth of Ca3TaAl3Si2O14 piezoelectric single crystal (2018)
  • Author(s): Yokota Yuui、Ohashi Yuji、Yoshino Masao、Yamaji Akihiro、Kurosawa Shunsuke、Kamada Kei、Yoshikawa Akira
  • Journal Title: Japanese Journal of Applied Physics Volume: 57 Pages: 11UD11～11UD11
  • DOI: 10.7567/JJAP.57.11UD11
  • Peer Reviewed
• [Journal Article] Fabrication of flexible Ir and Ir-Rh wires and application for thermocouple (2018)
  • Author(s): Murakami Rikito、Kamada Kei、Shoji Yasuhiro、Yokota Yuui、Yoshino Masao、Kurosawa Shunsuke、Ohashi Yuji、Yamaji Akihiro、Yoshikawa Akira
  • Journal Title: Journal of Crystal Growth Volume: 487 Pages: 72～77
  • DOI: 10.1016/j.jcrysgro.2018.01.018
  • Peer Reviewed
• [Journal Article] Li + , Na + and K + co-doping effects on scintillation properties of Ce:Gd 3 Ga 3 Al 2 O 12 single crystals (2018)
  • Author(s): Yoshino Masao、Kamada Kei、Kochurikhin Vladimir V.、Ivanov Mikhail、Nikl Martin、Okumura Satoshi、Yamamoto Seiichi、Yeom Jung Yeol、Shoji Yasuhiro、Kurosawa Shunsuke、Yokota Yuui、Ohashi Yuji、Yoshikawa Akira
  • Journal Title: Journal of Crystal Growth Volume: 491 Pages: 1～5
  • DOI: 10.1016/j.jcrysgro.2018.03.004
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Visualizing hidden electron trap levels in Gd3Al2Ga3O12:Ce crystals using a mid-infrared free-electron laser (2018)
  • Author(s): Kitaura Mamoru、Zen Heishun、Kamada Kei、Kurosawa Shunsuke、Watanabe Shinta、Ohnishi Akimasa、Hara Kazuhiko
  • Journal Title: Applied Physics Letters Volume: 112 Pages: 031112～031112
  • DOI: 10.1063/1.5008632
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Shallow electron traps formed by Gd2+ ions adjacent to oxygen vacancies in cerium-doped Gd3Al2Ga3O12 crystals (2018)
  • Author(s): Kitaura Mamoru、Watanabe Shinta、Kamada Kei、Jin Kim Kyoung、Yoshino Masao、Kurosawa Shunsuke、Yagihashi Toru、Ohnishi Akimasa、Hara Kazuhiko
  • Journal Title: Applied Physics Letters Volume: 113 Pages: 041906～041906
  • DOI: 10.1063/1.5043218
  • Peer Reviewed
• [Journal Article] Effects of Ca/Sr ratio control on optical and scintillation properties of Eu-doped Li(Ca,Sr)AlF 6 single crystals (2018)
  • Author(s): Yokota Yuui、Tanaka Chieko、Kurosawa Shunsuke、Yamaji Akihiro、Ohashi Yuji、Kamada Kei、Nikl Martin、Yoshikawa Akira
  • Journal Title: Journal of Crystal Growth Volume: 490 Pages: 71～76
  • DOI: 10.1016/j.jcrysgro.2018.03.022
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Use of YAP(Ce) in the development of high spatial resolution radiation imaging detectors (2018)
  • Author(s): Yamamoto Seiichi、Kamada Kei、Yoshikawa Akira
  • Journal Title: Radiation Measurements Volume: 119 Pages: 184～191
  • DOI: 10.1016/j.radmeas.2018.11.001
  • Peer Reviewed
• [Journal Article] Development of ultrahigh resolution radiation imaging detector using 1 mm channel size Si-PM array combined with 0.2 mm × 0.2 mm pixelated GAGG plate (2018)
  • Author(s): Yamamoto S.、Kataoka J.、Fukuchi T.、Kamada K.、Yoshikawa A.
  • Journal Title: Journal of Instrumentation Volume: 13 Pages: P05028～P05028
  • DOI: 10.1088/1748-0221/13/05/P05028
  • Peer Reviewed
• [Journal Article] Ultrahigh resolution radiation imaging system using an optical fiber structure scintillator plate (2018)
  • Author(s): Yamamoto Seiichi、Kamada Kei、Yoshikawa Akira
  • Journal Title: Scientific Reports Volume: 8 Pages: 3194～3203
  • DOI: 10.1038/s41598-018-21500-z
  • Peer Reviewed
• [Journal Article] Studies on sub-millimeter LYSO:Ce, Ce:GAGG, and a new Ce:GFAG block detector for PET using digital silicon photomultiplier (2018)
  • Author(s): Ullah Muhammad Nasir、Pratiwi Eva、Park Jin Ho、Yamamoto Seiichi、Kamada Kei、Yoshikawa Akira、Yeom Jung-Yeol
  • Journal Title: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Volume: 911 Pages: 115～122
  • DOI: 10.1016/j.nima.2018.09.029
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Thermoelectric Properties of Nb-Doped SrTiO3/TiO2 Eutectic Solids Fabricated by Unidirectional Solidification (2018)
  • Author(s): Yokota Yuui、Horii Shigeru、Ogino Hiraku、Yoshino Masao、Yamaji Akihiro、Ohashi Yuji、Kurosawa Shunsuke、Kamada Kei、Yoshikawa Akira
  • Journal Title: Journal of Electronic Materials Volume: 48 Pages: 1827～1832
  • DOI: 10.1007/s11664-018-06880-2
  • Peer Reviewed
• [Journal Article] Shape-controlled crystal growth of Fe-Ga alloys to apply a magnetostrictive vibration energy harvester (2018)
  • Author(s): Ito Masahiko、Kamada Kei、Yoshikawa Akira、Kawamata Toru、Fujieda Shun、Suzuki Shigeru、Minamitani Tamotsu、Ueno Toshiyuki
  • Journal Title: Journal of Alloys and Compounds Volume: 731 Pages: 898～902
  • DOI: 10.1016/j.jallcom.2017.10.109
  • Peer Reviewed
• [Presentation] シンチレータ結晶の魅力 (2019)
  • Author(s): 鎌田圭
  • Organizer: 関東核医学画像処理研究会2019
  • Invited
• [Presentation] 鉄-アルミニウム系合金結晶の形状制御作製と磁気特性評価 (2019)
  • Author(s): 鎌田 圭, 村上 力輝斗, 荒川 元孝, 南谷 保, 上野 敏幸, 庄子 育宏, 山路 晃弘, 吉野 将生, 黒澤 俊介, 横田 有為, 大橋 雄二, 吉川 彰
  • Organizer: 第66回応用物理学会春季学術講演会
• [Presentation] CeBr3シンチレータ単結晶の大型化とアッセンブリ技術の開発 (2019)
  • Author(s): 鎌田 圭, 吉野 将生, 庄子 育宏, 山路 晃弘, 黒澤 俊介, 横田 有為, 大橋 雄二, 島添 健次, 高橋 美和子, 羽場 宏光, 百瀬 敏光, 高橋 浩之, 吉川彰
  • Organizer: 第66回応用物理学会春季学術講演会
• [Presentation] Mo and W co-doping effects on Ce doped garnet scintillators (2018)
  • Author(s): Kei Kamada, Kyoung Jin Kim, Masao Yoshino, Yasuhiro Shoji, Vladimir V. Kochurikhin, Aya Nagura, Shunsuke Kurosawa, Yuui Yokota, Yuji Ohashi, Martin Nikl, Akira Yoshikawa
  • Organizer: The 5th International Conference on the Physics of Optical Materials and Devices
  • Int'l Joint Research
• [Presentation] Scintillation properties of undoped and Eu-doped Ca(Br,I)2 single crystals (2018)
  • Author(s): Kei Kamada, Takashi Iida, Yuki Furuya, Masao Yoshino4, Kyoung Jin Kim, Yasuhiko Shoji, Rikito Murakami, Akihiro Yamaji, Shunsuke Kurosawa, Yuji Ohashi, Yuui Yokota, and Akira Yoshikawa
  • Organizer: 10th International Conference on Luminescent Detectors and Transformers of Ionizing Radiation
  • Int'l Joint Research
• [Presentation] Development of growth technique for Tb doped GdAlO3/α-Al2O3 eutectic scintillator (2018)
  • Author(s): Kei Kamada, Hiroaki Yamaguchi, Akihiro Yamaji, Masao Yoshino, Shunsuke Kurosawa, Yasuhiro Shoji, Yuui Yokota, Yuji Ohashi, Akira Yoshikawa
  • Organizer: Sixth European Conference on Crystal Growth
  • Int'l Joint Research
• [Presentation] Crystal growth and scintillation properties of Eu doped Ca(BrxI1-x)2 (2018)
  • Author(s): K. Kamada, T. Iida, K. Kim, M. Yoshino, R. Murakami, Y. Furuya, A. Yamaji, S. Kurosawa, Y. Yokota, Y. Ohashi, A. Yoshikawa
  • Organizer: 2018 IEEE Nuclear science Symposium and Medical Imaging Conference
  • Int'l Joint Research
• [Presentation] Edge defined Film Fed Growth法によるCe添加YAlO3単結晶作製技術の開発 (2018)
  • Author(s): 鎌田 圭、古滝 敏郎、宮崎 真行、吉野 将生、山路 晃弘、黒澤 俊介、庄子 育宏、横田 有為、大橋 雄二、吉川 彰
  • Organizer: 第79回応用物理学会 秋季学術講演会
• [Presentation] EFG法による酸化物シンチレータ単結晶の形状制御育成 (2018)
  • Author(s): 鎌田圭、古滝敏郎、斎藤弘倫、 堀越文弥、宮崎真行、吉野将生、 山路晃広、黒澤俊介、庄子育宏、 横田有為、大橋雄二、吉川彰
  • Organizer: 第47回結晶成長国内会議
• [Patent(Industrial Property Rights)] 蛍光体 (2019)
  • Inventor(s): 鎌田 圭、吉川 彰、横田 有為、黒澤 俊介
  • Industrial Property Rights Holder: 鎌田 圭、吉川 彰、横田 有為、黒澤 俊介
  • Industrial Property Rights Type: 特許
  • Industrial Property Number: PCT/JP2019/008166
  • Overseas
• [Patent(Industrial Property Rights)] 蛍光体 (2018)
  • Inventor(s): 鎌田 圭、吉川 彰、黒澤 俊介、横田 有為
  • Industrial Property Rights Holder: 鎌田 圭、吉川 彰、黒澤 俊介、横田 有為
  • Industrial Property Rights Type: 特許
  • Industrial Property Number: 2018-037900