研究者詳細 - 瓜谷　章

論文 - 瓜谷　章

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Neutron Diagnostics in the Large Helical Device 査読有り

Isobe, M; Ogawa, K; Nishitani, T; Miyake, H; Kobuchi, T; Pu, N; Kawase, H; Takada, E; Tanaka, T; Li, SY; Yoshihashi, S; Uritani, A; Jo, J; Murakami, S; Osakabe, M

IEEE TRANSACTIONS ON PLASMA SCIENCE 46 巻 ( 6 ) 頁： 2050 - 2058 2018年6月

二種類の光刺激蛍光体と光ファイバーを用いたハイブリッド小型線量計による炭素線照射時に発生する消光現象の補正法の検討

平田悠歩、山﨑淳、渡辺賢一、吉橋幸子、瓜谷章、古場裕介、松藤成弘、柳田健之、福田健太郎

放射線 43 巻 ( 4 ) 頁： 139-142 2018年1月

In situ calibration of neutron activation system on the large helical device 査読有り

N. Pu, T. Nishitani, M. Isobe, K. Ogawa, H. Kawase, T. Tanaka, S. Y. Li, S. Yoshihashi and A. Uritani

Review of Scientific Instruments 88 巻 ( 11 ) 頁： 113302 2017年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

In situ calibration of the neutron activation system on the Large Helical Device (LHD) was performed by using an intense ²⁵²Cf neutron source. To simulate a ring-shaped neutron source, we installed a railway inside the LHD vacuum vessel and made a train loaded with the ²⁵²Cf source run along a typical magnetic axis position. Three activation capsules loaded with thirty pieces of indium foil-stacked with total mass of approximately 18 g were prepared. Each capsule was irradiated over 15 hours while the train was circulating. The activation response coefficient (9.4 ± 1.2)×10^-8 of ¹¹⁵In(n, n')^115mIn reaction obtained from the experiment is in good agreement with results by three-dimensional neutron transport calculations using the MCNP 6 code. The activation response coefficients for 2.45 MeV birth neutron and secondary 14.1 MeV neutron from deuterium plasma were evaluated from the activation response coefficient obtained in this calibration experiment.

Correction of quenching effect of a small size OSL dosimeter using Eu:BaFBr and Ce:CaF<sub>2</sub>

Hirata, Y; Watanabe, K; Uritani, A; Yamazaki, A; Koba, Y; Matsufuji, N; Yanagida, T; Fukuda, K

RADIATION MEASUREMENTS 106 巻頁： 246 - 251 2017年11月

<i>In situ</i> calibration of neutron activation system on the large helical device

Pu, N; Nishitani, T; Isobe, M; Ogawa, K; Kawase, H; Tanaka, T; Li, SY; Yoshihashi, S; Uritani, A

REVIEW OF SCIENTIFIC INSTRUMENTS 88 巻 ( 11 ) 2017年11月

名古屋大学における加速器BNCT用システムの開発― Li封入型ターゲットの除熱方法の検討― 招待有り

古澤大貴、瓜谷章、渡辺賢一、吉橋幸子、山崎淳、鬼柳善明、土田一輝、辻義之、恒吉達矢、浜地志憲、時谷政行、田村仁、相良明男

4 巻頁： 22-23 2017年9月

Correction of quenching effect of a small size OSL dosimeter using Eu:BaFBr and Ce:CaF₂ 査読有り

Yuho Hirata, KenichiWatanabe, AkiraUritani, AtsushiYamazaki, Yusuke Koba, Naruhiro Matsufuji, TakayukiYanagida, Kentaro Fukuda

Radiation Measurements 106 巻頁： 246-251 2017年4月

記述言語：英語掲載種別：研究論文（学術雑誌）

To accurately estimate an actual dose during radiotherapy treatment, dosimeters are required to be inserted into the affected region in a patient's body. Therefore, we are developing a small size dosimeter consisting of optical fibers and optically stimulated luminescence (OSL) elements. We fabricated two types of small size dosimeters using Eu:BaFBr and Ce:CaF₂. We measured the Bragg peak of high energy carbon ions in a water equivalent material. OSL materials showed the quenching effect when irradiated by high linear energy transfer (LET) particles. The sensitivity of Eu:BaFBr and Ce:CaF₂ monotonically decreased with different coefficients. The ratio of the signal intensity of these two OSL materials can uniquely determine the sensitivity of each OSL material. We corrected the quenching effect of the OSL dosimeters in the spread out Bragg peak with this relationship.

Particle Dependence of Quenching Effect in an Optical-Fiber-Type Optically Stimulated Luminescence Dosimeter

Hirata, Y; Watanabe, K; Yoshihashi, S; Uritani, A; Koba, Y; Naruhiro, MI; Yanagida, T; Toshito, T; Fukuda, K

SENSORS AND MATERIALS 29 巻 ( 10 ) 頁： 1455 - 1464 2017年

Upgrade of neutron energy spectrometer with single multilayer Bonner sphere using onion-like structure 査読有り

T. Mizukoshi, K. Watanabe, A. Yamazaki, A. Uritani, T. Iguchi, T. Ogata and T. Muramatsu

Journal of Radiation Protection and Research 41 巻 ( 3 ) 頁： 185-190 2016年9月

Quenching Effect in an Optical Fiber Type Small Size Dosimeter Irradiated with 290 MeV·u^-1 Carbon Ions 査読有り

41 巻 ( 3 ) 頁： 222-228 2016年9月

最近の核融合中性子工学の進展 7.国内施設の中性子工学

助川篤彦，瓜谷章，西村清彦，西谷健夫

プラズマ・核融合学会誌 92 巻 ( 4 ) 頁： 282-285 2016年4月

記述言語：日本語

国内の核融合実験装置の中で，すでに重水素実験を行ってきたJT- 60及び改造中のJT- 60SAと重水素実験の準備を進めているLHD の中性子工学の現状を紹介する．JT- 60 及びJT- 60SA では，MCNP とPHITS を主に使用して遮蔽設計等を行っており，JT- 60 では放射化箔を使用した中性子フルエンスの測定と良く一致した．またLHD では放射線安全評価を２次元輸送コードDORT で行うとともに，中性子計測の較正試験のシミュレーションをMCNP で行った．

Ce:CaF₂と光ファイバを用いた小型線量計の放射線応答に対する基礎検討

平田悠歩、渡辺賢一、山﨑淳、瓜谷章、古場裕介、松藤成弘、柳田健之、福田健太郎

放射線 41 巻 ( 3 ) 頁： 157-161 2016年

TRUST Eu:LiCAFを使用した多重球殻構造を有する単一減速球型中性子スペクトロメータに関する研究

水越友亮、渡辺賢一、山﨑淳、瓜谷章、井口哲夫、尾方智洋、村松貴史

放射線 41 巻 ( 3 ) 頁： 151-155 2016年

Study on Effects of Gamma-Ray Irradiation on TlBr Semiconductor Detectors 査読有り

Motohiro Matsumura, Kenichi Watanabe, Atsushi Yamazaki, Akira Uritani, Norihisa Kimura, Nobumichi Nagano, and Keitaro Hitomi

JPS Conf. Proc. 11 巻頁： 030005-1 - 030005-5 2016年

Wavelength-shifting fiber signal readout from Transparent RUbber SheeT (TRUST) type LiCaAlF₆ neutron scintillator 査読有り

Kenichi Watanabe, Takuya Yamazaki, Dai Sugimoto, Atsushi Yamazaki, Akira Uritani, Tetsuo Iguchi, Kentaro Fukuda, Sumito Ishidu, Takayuki Yanagida, Yutaka Fujimoto

Nuclear Instruments and Methods A 784 巻頁： 260-263 2015年6月

記述言語：英語掲載種別：研究論文（学術雑誌）

As an alternative to the standard 3He neutron detector, we are developing the Transparent RUbber SheeT type (TRUST)Eu doped LiCaAlF6 (Eu:LiCAF)scintillator. This type of neutron scintillator can easily be fabricated as a large area sheet. In order to take advantage of a large area detector, we try to read out scintillation photons using a wavelength-shifting fiber (WLSF) from a TRUSTEu:LiCAF scintillator. The TRUST Eu:LiCAF scintillator with the size of 50x50x5 mm3 was mounted on the WLSF plate and the end of the WLSFs was connected with a PMT. In order to reject high pulse height events induced in the WLSFs, we applied the pulse shape discrimination technique. The gamma-ray intrinsic and neutron
absolute detection efficiency is evaluated to be 8.8x10^7 and 9x103 cps/ng Cf(2m) for the TRUSTEu:
LiCAF scintillator with the size of 50x50x5 mm^3.

高エネルギーX 線源を用いた後方散乱X線によるコンクリート等の片面からの内部検査手法の開発招待有り

豊川弘之, 萬代新一, 瓜谷章, 渡辺賢一

非破壊検査頁： 0 2015年5月

Development of an optical fiber type detector using a Eu:LiCaAlF₆ scintillator for neutron monitoring in boron neutron capture therapy 査読有り

Kenichi Watanabe, Yuya Kawabata, Atsushi Yamazaki, Akira Uritani, Tetsuo Iguchi, Kentaro Fukuda, Takayuki Yanagida

Nuclear Instruments and Methods in Physics Research A A802 巻頁： 1-4 2015年

Portable Neutron Detector Using Ce:LiCaAlF₆ Scintillator 査読有り

Kenichi Watanabe, Takayuki Yanagida, Kentaro Fukuda, Akifumi Koike, Toru Aoki and Akira Uritani

SENSORS AND MATERIALS 27 巻 ( 3 ) 頁： 269-275 2015年

記述言語：英語掲載種別：研究論文（学術雑誌）

We fabricated a prototype portable neutron detector using a Ce:LiCaAlF₆ (Ce:LiCAF) scintillator and evaluated its basic performance. The weight of the fabricated detector including the battery is 800 g, significantly less than that of the conventional portable neutron detector, which weighs more than 5 kg. The neutron sensitivity of the fabricated detector is evaluated to be 2.3 cps/(mu Sv/h), comparable to that of the conventional detector. The gamma-ray intrinsic detection efficiency is evaluated to be less than 10(-6). The gamma-ray sensitivity is sufficiently low under ordinary circumstances. The expected count rate of the error counting due to the pile-up effect of gamma-ray-induced events is confirmed to be less than the background count rate for an incident gamma-ray rate of less than 10(4) gammas/s.

Study on fast luminescence component induced by gamma-rays in Ce doped LiCaAlF₆ scintillators 査読有り

Kenichi Watanabe, Yoshiyuki Kondo, Atsushi Yamazaki, Akira Uritani, Tetsuo Iguchi, Noriaki Kawaguchi, Kentaro Fukuda, Sumito Ishizu, Takayuki Yanagida, Yutaka Fujimoto, Akira Yoshikawa

Radiation Measurements 71 巻頁： 158-161 2014年12月

Scintillation properties of composite ceramic YAG and its capability on pulse shape descrimination 査読有り

Takayuki Yanagida, Kenichi Watanabe, Yutaka Fujimoto, Akira Uritani, Hideki Yagi and Takagimi Yanagitani

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN ( 122 ) 頁： 1016-1019 2014年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Transparent ceramic composite of non-doped and Ce-doped YAG was prepared by Konoshima Chemical with the vacuum sintering technique and investigated on pulse shape discrimination capability for functional collimator. Scintillation responses such as X-ray induced radioluminescence and decay time profiles of non-doped and Ce-doped YAG were evaluated. Pulse shape discrimination capability of the composite ceramic was evaluated by Cs-137 662 keV gamma-ray irradiation. As a result, clear separation of gamma-ray events at non-doped or Ce-doped YAG layers was observed in two dimensional histogram by using signal processing with two different shaping times. (C) 2014 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.122.1016

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