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Keitaro Hitomi

Section

Graduate School of Engineering

Job title

Professor

Degree

博士（工学）（東北工業大学）
修士 (工学) (東北工業大学)

researchmap

https://researchmap.jp/keitarohitomi

J-GLOBAL ID

201001065315224130

Research History 3

2004/04 - 2009/06

Faculty of Engineering, Tohoku Institute of Technology
2003/07 - 2004/03

Faculty of Engineering, University of Michigan
2001/04 - 2003/07

High-tech Research Center, Tohoku Institute of Technology

Education 2

Tohoku Institute of Technology　Graduate School, Division of Engineering　Division of Electronics

- 2001/03
Tohoku Institute of Technology　Faculty of Engineering　Department of Electronics

- 1997/03

Committee Memberships 20

日本学術振興会放射線科学とその応用第186委員会　委員

2017/07 - Present
六ヶ所村原子力安全管理委員会　委員

2016/06 - Present
SPIE Conference on Hard X-Ray, Gamma-Ray, and Neutron Detector Physics　Program Committee

2009/08 - Present
公益社団法人応用物理学会放射線分科会　幹事長

2022/04 - 2024/03
公益社団法人応用物理学会プログラム編集委員会　プログラム編集委員

2014/04 - 2021/03
日本原子力研究開発機構画期的なアプローチによる放射線計測技術について検討する分科会　委員

2017/06 - 2018/03
International Symposium on Radiation Detectors and Their Uses (ISRD2018)　Program Committee

2016/12 - 2018/01
一般社団法人日本原子力学会編集委員会　編集委員

2014/07 - 2017/06
青森県原子力人材育成・研究開発拠点施設運営検討委員会　委員

2015/02 - 2017/03
International Symposium on Radiation Detectors and Their Uses　Program Committee

2015/05 - 2016/01
第11回日本加速器学会年会実行委員会　実行委員

2014/01 - 2014/08
青森県原子力人材育成・研究開発活動計画検討委員会　委員

2013/10 - 2014/03
電気学会環境監視技術調査専門委員会　委員

2012/04 - 2014/03
青森県原子力人材育成・研究開発拠点計画検討委員会　委員

2012/10 - 2013/03
応用物理学会　プログラム編集委員

2008/04 - 2012/03
応用物理学会放射線分科会　幹事

2007/04 - 2009/03
応用物理学会放射線分科会　幹事

2005/04 - 2007/03
日本原子力学会　年会大会枠組み編成WG・プログラム編成WGメンバー

2015/04 -
日本原子力学会「2013年秋の大会」現地委員会　委員

2013/09 -
日本原子力学会放射線工学部会　運営幹事

2011/03 -

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Professional Memberships 2

日本原子力学会
応用物理学会

Research Interests 3

PET
臭化タリウム
半導体検出器

Research Areas 1

Nanotechnology/Materials / Applied physics - general /

Awards 5

第24回（2008年春季）応用物理学会講演奨励賞

2008/09　社団法人応用物理学会
(財）みやぎ産業科学振興基金研究奨励賞

2007/05　財団法人みやぎ産業科学振興基金
トーキン科学技術振興財団研究奨励賞

2004/03　トーキン科学技術振興財団
放射線賞（奨励賞）

2000/08　社団法人応用物理学会放射線分科会
東北支部第２回（１９９７年）講演奨励賞

1997/12　応用物理学会東北支部

Papers 187

Thallium bromide-based detector probe for particle-induced gamma-ray emission analysis Peer-reviewed

M. Nogami, K. Hitomi, S. Kubo, A. Terakawa, K. Ishii

International Journal of PIXE　1-7　2025/03/25
Publisher: World Scientific Pub Co Pte Ltd
DOI： 10.1142/s0129083524500049 　

ISSN： 0129-0835

eISSN： 1793-6616

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In this study, a gamma-ray detector probe with a thallium bromide (TlBr) semiconductor detector was developed for particle-induced gamma-ray emission (PIGE) analysis. Owing to the high atomic numbers of thallium (81) and bromine (35) and high density (7.56[Formula: see text]g/cm³) of TlBr, it exhibits a high photon stopping power, making it promising for PIGE analysis. An approximately 5-mm thick TlBr detector was fabricated from a crystal grown through the traveling-molten zone method using a zone-purified material. The detector comprised a planar cathode and small anode ([Formula: see text][Formula: see text]mm) surrounded by a guard electrode. The detector obtained full-width-at half-maximum (FWHM) energy resolutions of 1.7 and 1.6% for 356- and 511-keV gamma rays, respectively, at room temperature using a depth correction and rejection method based on the cathode-to-anode signal ratio. The TlBr detector probe was installed in a beamline at the Aomori Prefecture Quantum Science Center, Japan, where PIGE analysis was conducted using a 20-MeV proton beam. Gamma rays at 478[Formula: see text]keV from ⁷Li(p,p[Formula: see text])⁷Li reactions, 197 and 110[Formula: see text]keV from [Formula: see text]F(p,p[Formula: see text])[Formula: see text]F reactions, and 718[Formula: see text]keV from [Formula: see text]B(p,p[Formula: see text])[Formula: see text]B reactions were successfully detected using the proposed TlBr detector probe in PIGE analysis.
Accuracy of a whole‐body single‐photon emission computed tomography with a thallium‐bromide detector: Verification via Monte Carlo simulations Peer-reviewed

Toshimune Ito, Keitaro Hitomi, Michael Ljungberg, Sousei Kawasaki, Yuka Katayama, Akane Kato, Hirotatsu Tsuchikame, Kentaro Suzuki, Kyosuke Miyazaki, Ritsushi Mogi

Medical Physics　2025/02/27
Publisher: Wiley
DOI： 10.1002/mp.17724 　

ISSN： 0094-2405

eISSN： 2473-4209

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Abstract Background Single‐photon emission computed tomography (SPECT) devices equipped with cadmium–zinc–telluride (CZT) detectors achieve high contrast resolution because of their enhanced energy resolution. Recently, thallium bromide (TlBr) has gained attention as a detector material because of its high atomic number and density. Purpose This study evaluated the clinical applicability of a SPECT system equipped with TlBr detectors using Monte Carlo simulations, focusing on 99mTc and 177Lu imaging. Methods This study used the Simulation of Imaging Nuclear Detectors Monte Carlo program to compare the imaging characteristics between a whole‐body SPECT system equipped with TlBr (T‐SPECT) and a system equipped with CZT detectors (C‐SPECT). The simulations were performed using a three‐dimensional brain phantom and a National Electrical Manufacturers Association body phantom to evaluate 99mTc and 177Lu imaging. The simulation parameters were accurately set by comparing them with the actual measurements. Results The T‐SPECT system demonstrated improved energy resolution and higher detection efficiency than the C‐SPECT system. In 99mTc imaging, T‐SPECT demonstrated 1.71 times higher photopeak counts and improved contrast resolution. T‐SPECT exhibited a significantly lower impact of hole tailing and higher‐energy resolution (4.50% for T‐SPECT vs. 7.34% for C‐SPECT). Furthermore, T‐SPECT showed higher peak signal‐to‐noise ratio (PSNR) and structural similarity (SSIM) values, indicating better image quality. In 177Lu imaging, T‐SPECT showed 2.76 times higher photopeak counts and improved energy resolution (3.94% for T‐SPECT vs. 5.20% for C‐SPECT). T‐SPECT demonstrated a higher contrast recovery coefficient (CRC) and contrast‐to‐noise ratio (CNR) across all acquisition times, maintaining sufficient counts even with shorter acquisition times. Moreover, T‐SPECT acquired higher low‐frequency values in power spectrum density (PSD), indicating more accurate internal image reproduction. Conclusions T‐SPECT offers superior energy resolution and detection efficiency than C‐SPECT. Moreover, T‐SPECT can provide higher contrast resolution and sensitivity in clinical imaging with 99mTc and 177Lu. Furthermore, the Monte Carlo simulations are confirmed to be a valuable guide for the development of T‐SPECT.
Characterization of TlBr gamma detector based on electrical charge and Cherenkov light analysis Peer-reviewed

M. Hamdan, B. Feng, K. Shimazoe, M. Nogami, K. Hitomi, H. Takahashi, M. Uenomachi, H. Toyokawa

Journal of Instrumentation　19　(11)　C11017-C11017　2024/11/01
Publisher: IOP Publishing
DOI： 10.1088/1748-0221/19/11/c11017 　

eISSN： 1748-0221

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Abstract Thallium Bromide (TlBr) semiconductors have been extensively studied for their potential as room-temperature gamma-ray detectors, owing to their advantageous material properties. Recent advancements have demonstrated that timing performance in TlBr detectors can be enhanced by incorporating Cherenkov photon detection during gamma-ray interactions. In this study, TlBr detector (5 × 5 × 5 mm³) was investigated through a combined analysis of electrical charge and Cherenkov light signals. The depth of interaction (DoI) correction applied to the trapezoidal filter output yielded significant improvements in energy resolution, reducing it from 5.6% to as low as 2.51% FWHM at 511 keV and from 4.6% to as low as 1.94% FWHM at 662 keV, within specific C/A ratio ranges. The drift time, ranging from 2 to 30 μs, was found to be proportional to the C/A ratio, covering 4 to 9 photoelectrons. Furthermore, a time resolution of 511 ps was achieved at 6 photoelectrons, based on the FWHM of the time difference distribution in coincidence measurements at 511 keV using a ²²Na source. These results highlight the potential of TlBr detectors for achieving high energy and timing resolution in gamma detection, particularly for Compton-PET systems.
Comparison between carrier transport property and crystal quality of TlBr semiconductors Peer-reviewed

Kenichi Watanabe, Yusuke Sugai, Sota Hasegawa, Seishiro Tanaka, Keitaro Hitomi, Mitsuhiro Nogami, Takenao Shinohara, Yuhua Su, Joseph Don Parker, Winfried Kockelmann

Scientific Reports　14　(1)　2024/10/24
Publisher: Springer Science and Business Media LLC
DOI： 10.1038/s41598-024-76005-9 　

eISSN： 2045-2322

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Abstract Thallium bromide (TlBr) semiconductor detectors are being developed as promising candidates for high-detection-efficiency, high-energy-resolution, and room-temperature gamma-ray spectrometers. This study presents methods for evaluating TlBr crystal quality and carrier transport characteristics using neutron Bragg-dip imaging and the time-of-flight method for pulsed-laser-induced carriers, respectively. Neutron Bragg-dip imaging effectively determines the crystal orientation distribution, revealing crystal imperfections and grain boundaries. Time-of-flight measurements provide a spatial distribution of carrier mobility. In this study, two samples obtained from both the upstream and downstream region in the crystal ingot were evaluated. Although both samples show similar crystal quality, the upstream sample showed high carrier mobility across all areas, whereas the downstream sample exhibits low mobility in some areas. These findings suggest that, at least within the range of carrier mobility currently obtained, the effect of crystal integrity on carrier mobility is less significant than that of impurities. In conclusion, combining neutron Bragg-dip imaging with carrier mobility measurements offers a comprehensive approach to evaluating and improving TlBr detectors.
Characterization of long-term stability of thallium bromide detectors Peer-reviewed

Mitsuhiro Nogami, Kenichi Watanabe, Keitaro Hitomi

Japanese Journal of Applied Physics　2024/09/06
Publisher: IOP Publishing
DOI： 10.35848/1347-4065/ad7803 　

ISSN： 0021-4922

eISSN： 1347-4065

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Abstract Thallium bromide (TlBr) gamma ray detectors exhibit excellent spectroscopic performance at room temperature. Long-term stability is an essential property for the practical application of detectors. In this study, the long-term stability of the spectroscopic performance of the TlBr detectors was characterized by acquiring ¹³⁷Cs gamma-ray spectra at room temperature. TlBr detectors were fabricated from zone-purified TlBr crystals by constructing Tl electrodes. The TlBr detectors demonstrated stable spectroscopic performances for 1000-h operations at room temperature without bias polarity switching. The peak positions for the 662-keV gamma rays remained within ±1% of the average values for the 1000-h measurements. The detectors exhibited energy resolutions of ≤ 4.0% full width at half maximum for 662-keV gamma rays for 1000-h acquisitions without pulse height corrections. These results suggest that TlBr detectors with Tl electrodes are potential gamma-ray detectors for practical applications.
An experimental feasibility study of a 4π gamma-ray imager using detector response patterns Peer-reviewed

Yoshiharu Kitayama, Mitsuhiro Nogami, Keitaro Hitomi

Japanese Journal of Applied Physics　63　(7)　076502-076502　2024/07/01
Publisher: IOP Publishing
DOI： 10.35848/1347-4065/ad5ba0 　

ISSN： 0021-4922

eISSN： 1347-4065

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Abstract We constructed a gamma-ray imager that estimates the distribution of gamma-ray sources based on the response patterns of multiple gamma-ray detectors randomly positioned in three-dimensional space. The Coded Cube Camera for Gamma-ray (C3G), comprising eight Gd₃Al₂Ga₃O₁₂ (Ce) scintillator and eighteen lead cubes is housed in a cubical casing with an 86 mm edge length and weighs approximately 600 g. The results of the 4π imaging experiment confirmed the feasibility of imaging a 10 MBq ¹³⁷Cs source 3 m away for a 10 min measurement. C3G operates with only eight channels, instead of the hundreds needed by a typical imager. This setup allows for a simplified circuit and reconstruction algorithm, resulting in a cost-effective and reliable system. With its compact and lightweight design and 4π field of view, this technology is expected to find extensive applications in astronomy, medicine, nuclear security, and decommissioning projects.
The fabrication and characterization of direct conversion flat panel X-ray imager with TlBr film Peer-reviewed

Moh Hamdan, Kenji Shimazoe, Hiroyuki Takahashi, Mitsuhiro Nogami, Keitaro Hitomi, Shinya Asakura, Takanori Tsunashima, Takashi Nakamura

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment　169372-169372　2024/04
Publisher: Elsevier BV
DOI： 10.1016/j.nima.2024.169372 　

ISSN： 0168-9002
Simulation of a gamma-ray imaging technique using detector response patterns Peer-reviewed

Yoshiharu Kitayama, Mitsuhiro Nogami, Keitaro Hitomi

Japanese Journal of Applied Physics　63　(3)　032005-032005　2024/03/01
Publisher: IOP Publishing
DOI： 10.35848/1347-4065/ad2d7a 　

ISSN： 0021-4922

eISSN： 1347-4065

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Abstract We introduce a novel gamma-ray imaging technique that uses detector response patterns. This method employs multiple shielding cubes randomly positioned in a three-dimensional configuration. Within the volume defined by these cubes, a unique gamma-ray flux pattern is formed based on the incidence direction of the gamma rays. This pattern can be measured using the responses of several scintillator cubes. By pre-measuring the detector response pattern and incidence direction of the gamma rays, the incidence direction can be estimated using an unfolding technique. Simulations were performed using a ¹³⁷Cs point source. Our results show that a 10 MBq ¹³⁷Cs source, located 3 m away from the imager, can be imaged with an angular resolution close to 10°. These findings suggest that our new method is comparable to existing gamma-ray imaging techniques. Potential applications of this imaging method include nuclear power plant decommissioning, nuclear medicine, security, and astronomy.
Characterization of Plasma-etched Surfaces of TlBr Crystals for Radiation Detectors Peer-reviewed

Taro Nojima, Mitsuhiro Nogami, Toshiyuki Onodera, Keitaro Hitomi

Sensors and Materials　36　(1)　269-269　2024/01/26
Publisher: MYU K.K.
DOI： 10.18494/sam4703 　

ISSN： 0914-4935

eISSN： 2435-0869
Recombination Dynamics of Electron–Hole Pairs in TlBr Crystals Probed by Transient Absorption Spectroscopy Using Pulsed Electron Beams Peer-reviewed

Masanori Koshimizu, Yusa Muroya, Mitsuhiro Nogami, Keitaro Hitomi

Sensors and Materials　36　(1)　261-261　2024/01/26
Publisher: MYU K.K.
DOI： 10.18494/sam4694 　

ISSN： 0914-4935

eISSN： 2435-0869
Effective Volume of TlBr Semiconductor Detector Peer-reviewed

Sota Hasegawa, Kenichi Watanabe, Yusuke Sugai, Mitsuhiro Nogami, Keitaro Hitomi

Sensors and Materials　36　(1)　163-163　2024/01/26
Publisher: MYU K.K.
DOI： 10.18494/sam4632 　

ISSN： 0914-4935

eISSN： 2435-0869
Development of Time-of-flight Measurement System for Carrier Transport Characterization of TlBr Semiconductor Detectors Peer-reviewed

Yusuke Sugai, Kenichi Watanabe, Sota Hasegawa, Keitaro Hitomi, Mitsuhiro Nogami

Sensors and Materials　36　(1)　155-155　2024/01/26
Publisher: MYU K.K.
DOI： 10.18494/sam4631 　

ISSN： 0914-4935

eISSN： 2435-0869
Comparison Between Neutron Bragg Dip and Electron Backscatter Diffraction Images of TlBr Semiconductors Peer-reviewed

Kenichi Watanabe, Yusuke Sugai, Sota Hasegawa, Keitaro Hitomi, Mitsuhiro Nogami, Takenao Shinohara, Yuhua Su, Joseph Don Parker, Winfried Kockelmann

Sensors and Materials　36　(1)　149-149　2024/01/26
Publisher: MYU K.K.
DOI： 10.18494/sam4629 　

ISSN： 0914-4935

eISSN： 2435-0869
Compton Imaging Using Pixelated TlBr Semiconductor Detector Peer-reviewed

Keitaro Hitomi, Motohiro Matsumura, Kenichi Watanabe, Shusuke Maruyama, Mitsuhiro Nogami, Uritani Akira

Sensors and Materials　36　(1)　225-225　2024/01/26
Publisher: MYU K.K.
DOI： 10.18494/sam4672 　

ISSN： 0914-4935

eISSN： 2435-0869
Single Crystal Diamond Photon-Counting Imager

Toru Aoki, Kohei Toyoda, Koji Koyama, Seoun Woo Kim, Hiroki Kase, Junichi Nishizawa, Kento Tabata, Katsuyuki Takagi, Keitaro Hitomi

Proceedings of the International Display Workshops　1435-1435　2023/12/07
Publisher: International Display Workshops General Incorporated Association
DOI： 10.36463/idw.2023.1435 　

ISSN： 1883-2490
Single crystal diamond x-ray image sensor with photon-charge counting ROIC

Toru Aoki, Kohei Toyoda, Koji Koyama, Seong-Woo Kim, Junichi Nishizawa, Kento Tabata, Hiroki Kase, Katsuyuki Takagi, Keitaro Hitomi

Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XXV　19-19　2023/10/04
Publisher: SPIE
DOI： 10.1117/12.2681853 　
Reversible capacitive Frisch grid TlBr detectors Peer-reviewed

Mitsuhiro Nogami, Keitaro Hitomi, Toshiyuki Onodera, Kenichi Watanabe, Keizo Ishii

Japanese Journal of Applied Physics　62　(9)　096501-096501　2023/09/01
Publisher: IOP Publishing
DOI： 10.35848/1347-4065/acf0aa 　

ISSN： 0021-4922

eISSN： 1347-4065

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Abstract A reversible capacitive Frisch grid detector was fabricated using a thallium bromide (TlBr) crystal with a symmetrical electrode design. The device operates by switching the polarity of the applied voltage, which is necessary for a stable TlBr detector operation. A 2 mm × 2 mm × 5 mm bar-shaped TlBr crystal was used to construct the detector, which exhibited an (full width at half maximum) energy resolution of 1.9% for 662 keV γ-rays measured using a depth correction method at RT. The TlBr detector also showed a stable operation for 8 h of with hourly bias switching.
Characterization of coincidence time resolutions of TlBr _x Cl_1−x crystals as Cherenkov radiators Peer-reviewed

Keitaro Hitomi, Cheonghun Kim, Mitsuhiro Nogami, Kenji Shimazoe, Hiroyuki Takahashi

Japanese Journal of Applied Physics　62　(8)　081001-081001　2023/08/01
Publisher: IOP Publishing
DOI： 10.35848/1347-4065/ace5fa 　

ISSN： 0021-4922

eISSN： 1347-4065

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Abstract The coincidence time resolutions of thallium bromide chloride (TlBr_xCl_1−x) crystals used as Cherenkov radiators were characterized. A pair of TlBr_xCl_1−x crystals with the same composition was used to coincidentally detect positron annihilation gamma rays from a ²²Na source. The size of the crystals was approximately 3 mm × 3 mm × 3 mm. A polished surface of the crystals was coupled to a silicon photomultiplier. The time resolution improved with an increase in the Cl concentration in the crystals. TlBr_0.3Cl_0.7 crystals exhibited the best coincidence time resolutions of 378 ± 17 ps and 635 ± 31 ps with and without event selection based on the photoelectron level, respectively.
Experimental comparison of relative stopping power evaluation between proton CT and x-ray CT for pre-clinical proton irradiation studies of small animals Peer-reviewed

Atsuki Terakawa, Hibiki Hosokawa, Mitsuhiro Nogami, Keitaro Hitomi, Keizo Ishii

Physics in Medicine & Biology　2023/04/03
Publisher: IOP Publishing
DOI： 10.1088/1361-6560/acc9fa 　

ISSN： 0031-9155

eISSN： 1361-6560

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Abstract Proton therapy experiments in small animals are useful not only for pre-clinical and translational studies, but also for the development of advanced technologies for high-precision proton therapy. Accuracy of small animal treatment plans is as important as in clinical treatment plans to ensure precise delivery of the proton dose. While treatment planning for proton therapy is currently based on the stopping power of protons relative to water (i.e., the relative stopping power [RSP]), estimated by converting Hounsfield units (HU) into RSP (HU-RSP conversion) in reconstructed X-ray computed tomography (XCT) images, the HU-RSP conversion causes uncertainties in RSP, which affect the accuracy of dose simulation in patients. Proton computed tomography (pCT) has attracted a great deal of attention due to its potential to reduce RSP uncertainties in clinical treatment planning, and is additionally expected to provide improved accuracy during small animal treatment planning. However, as the proton energies for irradiating small animals are much lower than those used clinically, the energy dependence of RSP may negatively affect pCT-based RSP evaluation.&#xD;We evaluated the RSPs of 10 water- and tissue-equivalent materials with known constituent elements based on pCT measurements conducted at 73.65 MeV, and compared them with XCT-based and calculated RSPs to investigate energy dependence and achieve more accurate RSPs for treatment planning in small animals. The results demonstrated that despite the low proton energy, with the pCT approach for RSP evaluation smaller root mean square deviation (1.9%) of RSP from the theoretical prediction is still achieved compared to conventional HU-RSP conversion with XCT (6.1%), which is expected to improve the accuracy of proton therapy treatment planning in pre-clinical studies of small animals.
Neutron-induced thermoluminescence of Dy3+-doped Li2O–Al2O3–B2O3 glasses Peer-reviewed

Hiroto Yamaguchi, Masanori Koshimizu, Hajime Komiya, Hiroki Kawamoto, Yutaka Fujimoto, Genichiro Wakabayashi, Mitsuhiro Nogami, Keitaro Hitomi, Kenichi Watanabe, Keisuke Asai

Journal of Materials Science: Materials in Electronics　33　(35)　26424-26433　2022/11/01
Publisher: Springer Science and Business Media LLC
DOI： 10.1007/s10854-022-09322-2 　

ISSN： 0957-4522

eISSN： 1573-482X
Evaluation of the thermal neutron sensitivity, output linearity, and gamma-ray response of optical fiber-based neutron detectors using Li-glass scintillator Peer-reviewed

Akihisa Ishikawa, Kenichi Watanabe, Atsushi Yamazaki, Sachiko Yoshihashi, Shigefumi Imai, Akihiko Masuda, Tetsuro Matsumoto, Hiroki Tanaka, Yoshinori Sakurai, Mitsuhiro Nogami, Keitaro Hitomi, Akira Uritani, Hideki Harano

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment　1025　2022/02/11

DOI： 10.1016/j.nima.2021.166074 　

ISSN： 0168-9002
Spatial Resolution of X-ray Imaging Using 80 µm Pitch TlBr Detector

Kohei Toyoda, Katsuyuki Takagi, Hiroki Kase, Toshiyuki Takagi, Kento Tabata, Tsuyoshi Terao, Hisashi Morii, AKifumi Koike, Toru Aoki, Mitsuhiro Nogami, Keitaro Hitomi

Research and Education: Traditions and Innovations　345-351　2022
Publisher: Springer Singapore
DOI： 10.1007/978-981-19-0379-3_36 　

ISSN： 2367-3370

eISSN： 2367-3389
Bias Polarity Switching-Type TlBr X-Ray Imager Peer-reviewed

Katsuyuki Takagi, Kohei Toyoda, Hiroki Kase, Toshiyuki Takagi, Kento Tabata, Tsuyoshi Terao, Hisashi Morii, Akifumi Koike, Toru Aoki, Mitsuhiro Nogami, Keitaro Hitomi

IEEE Transactions on Nuclear Science　68　(9)　2435-2439　2021/09
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
DOI： 10.1109/tns.2021.3078448 　

ISSN： 0018-9499

eISSN： 1558-1578
Neutron detection via thermoluminescence of Tb3+-doped Li2O–Al2O3–B2O3 glasses Peer-reviewed

Ichiro Kawamura, Hiroki Kawamoto, Yutaka Fujimoto, Masanori Koshimizu, Go Okada, Genichiro Wakabayashi, Mitsuhiro Nogami, Keitaro Hitomi, Kenichi Watanabe, Takayuki Yanagida, Keisuke Asai

Japanese Journal of Applied Physics　60　(3)　036002-036002　2021/03/01

DOI： 10.35848/1347-4065/abdf7d 　

ISSN： 0021-4922

eISSN： 1347-4065
Demonstration of using TlBr detectors for X-ray Imager

Takagi Katsuyuki, Toyoda Kohei, Kase Hiroki, Takagi Toshiyuki, Tabata Kento, Terao Tsuyoshi, Morii Hisashi, Koike Akifumi, Aoki Toru, Nogami Mitsuhiro, Hitomi Keitaro

JSAP Annual Meetings Extended Abstracts　2021.1　436-436　2021/02/26
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/jsapmeeting.2021.1.0_436 　

eISSN： 2436-7613
Demonstration of polarization behavior of TlBr x-ray imager with silver electrodes

Katsuyuk Takagi, Kohei Toyoda, Hiroki Kase, Toshiyuki Takagi, Kento Tabata, Tsuyoshi Terao, Hisashi Morii, Akifumi Koike, Toru Aoki, Mitsuhiro Nogami, Keitaro Hitomi

Proceedings of SPIE - The International Society for Optical Engineering　11838　2021
Publisher: SPIE
DOI： 10.1117/12.2596374 　

ISSN： 1996-756X 0277-786X
Proton-induced X-ray emission analysis of white birch milk

E. Ohkoshi, S. Horimatsu, T. Tada, K. Hitomi, M. Nogami, K. Ishii

International Journal of PIXE　30　(03n04)　85-89　2020/12
Publisher: World Scientific Pub Co Pte Ltd
DOI： 10.1142/s0129083520500102 　

ISSN： 0129-0835

eISSN： 1793-6616

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We subjected white birch milk to X-ray emission analysis. The mineral levels changed over time. White birch seasonality (sprouting in early spring and fruition in autumn) affected the mineral levels.
Proton-induced X-ray emission analysis of the Chinese yam

M. Nogami, K. Hitomi, K. Ishii

International Journal of PIXE　30　(03n04)　77-83　2020/12
Publisher: World Scientific Pub Co Pte Ltd
DOI： 10.1142/s0129083520500096 　

ISSN： 0129-0835

eISSN： 1793-6616

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The Chinese yam is a major component of the Japanese diet consumed in raw and cooked form. It is important to determine the nutrient contents of yam, which contains high potassium levels; a simple measurement method is required. We performed proton-induced X-ray emission (PIXE) analysis of fully grown and immature yams. Analysis of the yam trunk, skin, and hair roots revealed that the skin potassium concentration was 10-fold higher than that of the trunk; consumption of the skin is thus recommended. Longitudinal measurements of mineral concentrations in a growing yam revealed that the concentrations increased in the growth direction.
Development of thallium bromide semiconductor detectors for particle-induced gamma-ray emission

K. Hitomi, M. Nogami, A. Terakawa, K. Ishii

International Journal of PIXE　30　(03n04)　63-68　2020/12
Publisher: World Scientific Pub Co Pte Ltd
DOI： 10.1142/s0129083520500072 　

ISSN： 0129-0835

eISSN： 1793-6616

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A thallium bromide (TlBr) gamma-ray detector was developed for particle-induced gamma-ray emission (PIGE) applications. The PIGE spectrum of a lithium fluoride (LiF) crystal was obtained for the first time using the TlBr detector. This detector was fabricated using a zone-purified crystal with dimensions of approximately 2mm × 2mm × 5mm. An energy resolution of 2.3% full-width at half maximum for 511 keV gamma rays was obtained from the detector at room temperature. The LiF crystal target was irradiated with a 20 MeV proton beam at the Aomori Prefecture Quantum Science Center. Full-energy peaks of 478 keV and 197 keV were successfully detected from lithium and fluorine, respectively, using the TlBr detector in the PIGE experiment.
Feasibility study of TlBr semiconductor detectors for PIXE applications Peer-reviewed

Mitsuhiro Nogami, Keitaro Hitomi, Toshiyuki Onodera, Kio Matsumoto, Kenichi Watanabe, Atsuki Terakawa, Keizo Ishii

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms　477　43-45　2020/08
Publisher: Elsevier BV
DOI： 10.1016/j.nimb.2019.10.003 　

ISSN： 0168-583X
A trial application of particle-induced X-ray emission analysis to microplastic samples collected from the seashore Peer-reviewed

R. Shimizu, H. Hinata, T. Mori, T. Asakawa, M. Satoh, M. Nogami, K. Hitomi, K. Ishii

International Journal of PIXE　30　(01n02)　23-29　2020/06
Publisher: World Scientific Pub Co Pte Ltd
DOI： 10.1142/s0129083520500035 　

ISSN： 0129-0835

eISSN： 1793-6616

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Here, we apply 20 MeV particle-induced X-ray emission (PIXE) to elemental analysis of microplastic samples with a diameter of approximately 2 mm, collected from the seashores of the northeastern area of Honshu in Japan. The samples were in a grain form with unwanted elements adhering to their surfaces. The PIXE measurements were conducted in a helium atmosphere. For normalization, the number of K X-rays of the residual gas argon was used instead of the directly measured beam irradiation, and the number of continuous X-rays in the PIXE spectrum was used instead of the mass of each sample. Thirteen elements were identified on the microplastics, among which were toxic chromium and lead. Thus, PIXE analysis is useful for analyzing microplastic samples.
Crystalline Characterization of TlBr Semiconductor Detectors Using Wavelength-resolved Neutron Imaging Peer-reviewed

Kenichi Watanabe, Kio Matsumoto, Akira Unitani, Keitaro Hitomi, Mitsuhiro Nogami, Winfried Kockelmann

Sensors and Materials　32　(4)　1435-1435　2020/04/20
Publisher: MYU K.K.
DOI： 10.18494/sam.2020.2744 　

ISSN： 0914-4935
Transient Absorption Spectroscopy of TlBr Crystals Using Pulsed Electron Beams Peer-reviewed

Masanori Koshimizu, Yusa Muroya, Shinichi Yamashita, Mitsuhiro Nogami, Keitaro Hitomi, Yutaka Fujimoto, Keisuke Asai

Sensors and Materials　32　(4)　1445-1445　2020/04/20
Publisher: MYU K.K.
DOI： 10.18494/sam.2020.2754 　

ISSN： 0914-4935
Spectrometric Estimation of Dose Rate Induced from Radioactive Cesium in the Ground Using a Mobile Gamma-Ray Spectrometry Based on a LaBr3(Ce) Detector Peer-reviewed

Young-Yong Ji, Taehyung Lim, Keitaro Hitomi, Tatsuo Yajima

Health Physics　118　(2)　215-225　2020/02
Publisher: Ovid Technologies (Wolters Kluwer Health)
DOI： 10.1097/hp.0000000000001139 　

ISSN： 0017-9078
Photoluminescence and scintillation of TlBr crystals at low temperatures Peer-reviewed

Masanori Koshimizu, Keitaro Hitomi, Mitsuhiro Nogami, Takayuki Yanagida, Yutaka Fujimoto, Keisuke Asai

Japanese Journal of Applied Physics　59　(SC)　SCCB19-SCCB19　2020/02/01
Publisher: IOP Publishing
DOI： 10.7567/1347-4065/ab4895 　

ISSN： 0021-4922

eISSN： 1347-4065
Neutron-induced thermoluminescence properties of Tb3+-doped CaO-Al2O3-B2O3 glasses

Ichiro Kawamura, Hiroki Kawamoto, Yutaka Fujimoto, Masanori Koshimizu, Go Okada, Yusuke Koba, Ryo Ogawara, Takayuki Yanagida, Keisuke Asai

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN　127　(10)　663-668　2019/10

DOI： 10.2109/jcersj2.19071 　

ISSN： 1882-0743

eISSN： 1348-6535
Assessment of radioactive cesium deposition using ground-based gamma-ray spectrometry with a LaBr3(Ce) detector Peer-reviewed

Young-Yong JI, Taehyung LIM, Keitaro HITOMI, Tatsuo YAJIMA

Journal of Radiological Protection　39　(4)　1006-1020　2019/09
DEVELOPMENT OF THALLIUM BROMIDE GAMMA-RAY SPECTROMETERS FOR FUKUSHIMA DECOMMISSIONING

Mitsuhiro Nogami, Keitaro Hitomi, Tatsuo Torii, Yuki Sato, Yoshihiko Tanimura, Kuniaki Kawabata, Yoshihiro Furuta, Hiroshi Usami, Kenichi Watanabe, Toshiyuki Onodera, Norihisa Kimura, Shin Kubo, Seong-Yun Kim, Tatsuya Ito, Keizo Ishii, Hiroyuki Takahashi

Proceedings of FDR2019　FDR2019-1110　2019/07
Water-equivalent Lengths Derived from Proton Computed Tomography

A. Terakawa, H. Hosokawa, K. Shigihara, A. Kajiyama, R. Nagao, K. Narumi, H. Hosokawa, Y. Fujise, H. Ushijima, Y. Wakayama, M. Fujiwara, K. Hitomi, Y. Nagano, M. Nogami

CYRIC Annual Report 2016-2017　91-93　2019/04
Prompt Gamma-Ray Detection with TlBr Detectors for Proton Radiation Therapy

K. Hitomi, T. Higuma, H. Hosokawa, M. Nogami, A. Terakawa

CYRIC Annual Report 2016-2017　50-52　2019/04
Development of a 20MeV proton particle-induced X-ray emission analysis method in a helium atmosphere

Keizo Ishii, Atsuki Terakawa, Keitaro Hitomi, Mitsuhiro Nogami

International Journal of PIXE　29　(03n04)　113-117　2019/01
Publisher: World Scientific Pub Co Pte Lt
DOI： 10.1142/s0129083519500219 　

ISSN： 0129-0835

eISSN： 1793-6616

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We developed a 20[Formula: see text]MeV particle-induced X-ray emission (PIXE) analysis method using a medical cyclotron, which is conventionally used for positron emission tomography analysis performed in vacuo, during which the target sample is damaged. For non-destructive analysis and ease of switching between target samples, we developed a technique allowing 20[Formula: see text]MeV proton PIXE analysis to be performed at the atmospheric pressure. We filled the PIXE analysis chamber with helium and checked that the continuous background of the Compton tails of nuclear reaction [Formula: see text]-rays increased only minimally, and that the quasi-free electron bremsstrahlung (QFEB) did not increase at all, in the X-ray energy spectrum.
First in-beam application of thallium bromide semiconductor detectors to particle-induced X-ray emission Peer-reviewed

M. Nogami, K. Hitomi, A. Terakawa, K. Ishii

International Journal of PIXE　29　(01n02)　53-59　2019/01
Publisher: World Scientific Pub Co Pte Lt
DOI： 10.1142/s0129083519500153 　

ISSN： 0129-0835

eISSN： 1793-6616

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For the first time, particle-induced X-ray emission (PIXE) spectra were obtained using TlBr detectors. The TlBr detector was fabricated from a crystal grown with material purified by the zone purification. Its active volume was 1.5 mm × 1.5 mm × 3.1 mm, and it exhibited an energy resolution of a 6.2 keV full-width at half-maximum (FWHM) for 59.5 keV at room temperature. The detector was installed into a PIXE system at Aomori Prefecture Quantum Science Center. A Pb plate target in the PIXE chamber was irradiated with a 20 MeV proton beam, and X-ray peaks for Pb K[Formula: see text] and K[Formula: see text] were successfully detected by the TlBr detector at room temperature.
Fabrication of Small-volume Thallium Bromide Gamma-ray Detectors for High-intensity Radiation Fields Peer-reviewed

Mitsuhiro Nogami, Keitaro Hitomi, Nobumichi Nagano, Toshiyuki Onodera, Norihisa Kimura, Hiroki Sunaba, Makoto Kosaka, Shin Kubo, Seong-Yun Kim, Tatsuya Ito, Kenichi Watanabe, Keizo Ishii

Proceedings of the Second International Symposium on Radiation Detectors and Their Uses (ISRD2018), JPS Conference Proceedings　24　011017　2019/01
Evaluation of Antimony Tri-Iodide Crystals for Radiation Detectors Peer-reviewed

Toshiyuki Onodera, Koei Baba, Keitaro Hitomi

Science and Technology of Nuclear Installations　2018　1532742　2018/12
六ケ所核燃料再処理施設用セシウムガンマ線モニタリングシステムの開発 Peer-reviewed

木村乃久, 人見啓太朗, 長野宣道, 金聖潤, 伊藤辰也, 石井慶造

放射線　44　(3)　75-83　2018/11
Pulse-height loss in the signal readout circuit of compound semiconductor detectors Peer-reviewed

M. Nakhostin, K. Hitomi

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment　893　146-150　2018/06/11
Publisher: Elsevier B.V.
DOI： 10.1016/j.nima.2018.03.053 　

ISSN： 0168-9002
Theoretical detection limit of PIXE analysis using 20 MeV proton beams Peer-reviewed

Keizo Ishii, Keitaro Hitomi

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms　417　37-40　2018/02/15
Publisher: Elsevier B.V.
DOI： 10.1016/j.nimb.2017.10.008 　

ISSN： 0168-583X
Use of a medical positron emission tomography cyclotron to perform proton-induced X-ray emission analysis

Keizo Ishii, Atsuki Terakawa, Hiroki Ushijima, Keitaro Hitomi, Nobumichi Nagano, Mitsuhiro Nogami

International Journal of PIXE　28　(03n04)　93-100　2018/01
Publisher: World Scientific Pub Co Pte Lt
DOI： 10.1142/s0129083518500183 　

ISSN： 0129-0835

eISSN： 1793-6616

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We explored whether medical positron emission tomography (PET) cyclotron proton beams could be used for proton-induced X-ray emission (PIXE) analysis. The beam current of the medical PET cyclotron is high, as required for radioisotope production, and is not commonly used for PIXE analysis. We successfully extracted stable proton beams of low intensity by using the ion source of a medical cyclotron to exploit proton impurities in deuteron gas. We performed 20-MeV PIXE analysis of a biological sample (used tea leaves). Elements lighter than Sr could be detected with high sensitivity ([Formula: see text]14 ppm) using a silicon drift detector. We thus showed that a medical cyclotron widely used for PET diagnosis could be employed for PIXE analysis of biological samples.
Recent results from pixelated TlBr detectors with Tl electrodes operated at room-temperature

Charles Leak, William Koehler, Sean O'Neal, Zhong He, Keitaro Hitomi

2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop, NSS/MIC/RTSD 2016　2017-　2017/10/16
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/NSSMIC.2016.8069952 　
Cs(I) and Sr(II) Separation from High-level Liquid Waste using Extractant with Ionic Liquid Impregnated on SiO2-P Adsorbents and Its Kinetic, Equilibrium and Adsorption studies Peer-reviewed

Seong-Yun Kim, Tatsuya Kudo, Tatsuya Ito, Nobumichi Nagano, Keitaro Hitomi

Proceedings of GLOBAL 2017 (International Nuclear Fuel Cycle Conference)　1-4　2017/09
Effects of γ-ray Irradiation on Thiodiglycolamide-type Extractant-impregnated Adsorbents for Separation of Platinum Group Metals from High-level Liquid Waste Peer-reviewed

Tatsuya Ito, Seong-Yun Kim, Nobumichi Nagano, Keitaro Hitomi

Energy Procedia　131　195-202　2017
Publisher: Elsevier Ltd
DOI： 10.1016/j.egypro.2017.09.427 　

ISSN： 1876-6102
Study on Effects of Gamma-Ray Irradiation on TlBr Semiconductor Detectors Peer-reviewed

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

Proceedings of International Symposium on Radiation Detectors and Their uses (ISRD2016), JPS Conference Proceedings　11　30005　2016/11/14

DOI： 10.7566/JPSCP.11.030005 　
Fabrication of double-sided thallium bromide strip detectors Peer-reviewed

Keitaro Hitomi, Nobumichi Nagano, Toshiyuki Onodera, Seong-Yun Kim, Tatsuya Ito, Keizo Ishii

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　823　15-19　2016/07

DOI： 10.1016/j.nima.2016.03.107 　

ISSN： 0168-9002

eISSN： 1872-9576
クラウンエーテル含有イオン液体抽出系を用いた高レベル放射性廃液からのSr(II)の選択的分離 Peer-reviewed

高橋正幸, 伊藤辰也, 金聖潤, 徳田玄明, 長野宣道, 人見啓太朗, 石井慶造

日本イオン交換学会誌　27　(2)　21-26　2016

DOI： 10.5182/jaie.27.21 　
Effect of nitrate on corrosion of austenitic stainless steel in boiling nitric acid solution containing chromium ions Peer-reviewed

Satoshi Hasegawa, Seong-Yun Kim, Tetsunari Ebina, Haruaki Tokuda, Tatsuya Ito, Nobumichi Nagano, Keitaro Hitomi, Keizo Ishii

JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY　53　(9)　1332-1341　2016

DOI： 10.1080/00223131.2015.1107514 　

ISSN： 0022-3131

eISSN： 1881-1248
Experimental Determination of the Ionization Energy in TlBr Peer-reviewed

Keitaro Hitomi, Toshiyuki Onodera, Seong-Yun Kim, Tadayoshi Shoji, Keizo Ishii

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　62　(3)　1251-1254　2015/06

DOI： 10.1109/TNS.2015.2430971 　

ISSN： 0018-9499

eISSN： 1558-1578
Redox behavior of chromium on the corrosion of austenitic stainless steel (R-SUS304ULC) in 8M nitric acid solution Peer-reviewed

Satoshi Hasegawa, Tetsunari Ebina, Haruaki Tokuda, Masahiko Inaguma, Keitaro Hitomi, Keizo Ishii, Seong-Yun Kim

JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY　52　(4)　530-540　2015/04

DOI： 10.1080/00223131.2014.962637 　

ISSN： 0022-3131

eISSN： 1881-1248
Adsorption Behavior of Platinum Group Metals onto a Silica-based (Crea+Dodec)/SiO2-P Extraction Resin from Simulated High Level Liquid Waste Peer-reviewed

Yuanlai Xu, Seong-Yun Kim, Tatsuya Ito, Haruki Tokuda, Keitaro Hitomi, Keizo Ishii

SEPARATION SCIENCE AND TECHNOLOGY　50　(2)　260-266　2015/01

DOI： 10.1080/01496395.2014.956222 　

ISSN： 0149-6395

eISSN： 1520-5754
Investigation on Selective Separation of Sr(II) from High Level Liquid Waste Using a Macroporous Silica-based Absorbent Peer-reviewed

Seong-Yun Kim, Tatsuya Ito, Yuanlai Xu, Keitaro Hitomi, Keizo Ishii

GLOBAL2015　1575-1581　2015
Discussion on Applicability of Macroporous Silica-based Adsorbents to Multistep Partitioning Process of High Level Liquid Waste Peer-reviewed

Tatsuya Ito, Seong-Yun Kim, Yuanlai Xu, Atsushi Yoshida, Keitaro Hitomi, Keizo Ishii

GLOBAL2015　1590-1596　2015
Effect of boiling phenomena on the corrosion of austenitic stainless steel (R-SUS304ULC) in nitric acid solution containing chromium ions Peer-reviewed

Satoshi Hasegawa, Tetsunari Ebina, Haruaki Tokuda, Keitaro Hitomi, Keizo Ishii, Seong-Yun Kim

ICONE23　2015　(23)　1-6　2015
Publisher: The Japan Society of Mechanical Engineers

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The redox behavior of chromium was investigated under three conditions for the nitric acid solutions considering the operating conditions of the reprocessing plant -atmospheric-pressure boiling, reduced-pressure boiling, and atmospheric-pressure non-boiling-to determine the relationship between the corrosion of austenitic stainless steel (R-SUS304ULC) and this behavior. The oxidation of Cr(III) to Cr(VI) in 8 M boiling nitric acid was increased over that in non-boiling nitric acid, even at the same temperature by measuring the time dependence of the chromium concentration and thermodynamic calculations. These results show that Cr(III) is more likely to oxidize under boiling than non-boiling conditions. On the other hand, the apparent rate of Cr(VI) reduction, as consumed by corrosion of the stainless steel, was more than 10 times greater than the rate of Cr(III) oxidation in 8 M nitric acid solution. This is evidence that the rate of Cr(VI) reduction by corrosion is kinetically faster than the rate of Cr(III) oxidation. In addition, the apparent rate of Cr(VI) reduction and the corrosion rate of R-SUS304ULC were positively correlated. Therefore, these indicate that the corrosion of R-SUS304ULC apparently follows Arrhenius' law in 8 M nitric acid solution containing Cr(VI), regardless of the boiling or non-boiling conditions.
New compound semiconductor gamma-ray detectors Invited

Keitaro HITOMI

OYO BUTURI　83　(9)　757-760　2014/09/10
Publisher:
ISSN： 0369-8009
Characterization of pixelated TlBr detectors with Tl electrodes Peer-reviewed

Keitaro Hitomi, Toshiyuki Onodera, Seong-Yun Kim, Tadayoshi Shoji, Keizo Ishii

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　747　7-12　2014/05

DOI： 10.1016/j.nima.2014.02.020 　

ISSN： 0168-9002

eISSN： 1872-9576
Evaluation of Long-Term Stability of TlBr Detectors for the Nuclear Spent Fuel Reprocessing Plant

Kimura N, Hitomi K, Kim S.-Y, Ishii K

CYRIC Annual Report 2012-2013　2012　73-75　2014
Publisher: Cyclotron and Radioisotope Center, Tohoku University
Adsorption behavior of trivalent americium and rare earth ions onto a macroporous silica-based isobutyl-BTP/SiO2-P adsorbent in nitric acid solution Peer-reviewed

Yuanlai Xu, Seong-Yun Kim, Tatsuya Ito, Keitaro Hitomi, Etsushu Kuraoka, Shigekazu Usuda, Keizo Ishii

JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY　299　(1)　149-155　2014/01

DOI： 10.1007/s10967-013-2747-9 　

ISSN： 0236-5731

eISSN： 1588-2780
Study on Separation of Platinum Group Metals from High Level Liquid Waste Using Solid State Adsorbent

Ito T, Kim S.-Y, Xu Y, Hitomi K, Ishii K, Nagaishi R, Kimura T

CYRIC Annual Report 2012-2013　2012　101-106　2014
Publisher: Cyclotron and Radioisotope Center, Tohoku University
Development of measurement systems using a aqueos solution of N,N-dimethyl formamide for gaseous radioactive methyl iodide in nuclear power plant accidents

Tokuda H, Kim S.-Y, Takahashi T, Hasegawa S, Hitomi K, Ishii K

CYRIC Annual Report 2012-2013　2012　118-123　2014
Publisher: Cyclotron and Radioisotope Center, Tohoku University
Extraction of Cesium and Strontium from Nitric Acid Solution using Ionic liquids

Takahashi T, Kim S.-Y, Tokuda H, Hitomi K, Ishii K

CYRIC Annual Report 2012-2013　2012　113-117　2014
Publisher: Cyclotron and Radioisotope Center, Tohoku University
Electrochemical Proparties of Austenitic Stainless Steel(R-SUS304ULC) in Nitric Acid Solution

Hasegawa S, Kim S. -Y, Ebina T, Tokuda H, Hitomi K, Ishii K

CYRIC Annual Report 2012-2013　2012　107-112　2014
Publisher: Cyclotron and Radioisotope Center, Tohoku University
Adsorption Behaviors of Platinum Group Metals in Simulated High Level Liquid Waste Using Macroporous (MOTDGA-TOA)/SiO2-P Silica-based Absorbent Peer-reviewed

Tatsuya Ito, Seong-Yun Kim, Yuanlai Xu, Keitaro Hitomi, Keizo Ishii, Ryuji Nagaishi, Takaumi Kimura

SEPARATION SCIENCE AND TECHNOLOGY　48　(17)　2616-2625　2013/11

DOI： 10.1080/01496395.2013.807290 　

ISSN： 0149-6395

eISSN： 1520-5754
臭化タリウム半導体検出器 Invited

人見啓太朗, 石井慶造

Isotope News　715　27-29　2013/11
Chromatographic separation of platinum group metals from simulated high level liquid waste using macroporous silica-based adsorbents Peer-reviewed

Yuanlai Xu, Seong-Yun Kim, Tatsuya Ito, Haruki Tokuda, Keitaro Hitomi, Keizo Ishii

Journal of Chromatography A　1312　37-41　2013/10/18

DOI： 10.1016/j.chroma.2013.08.089 　

ISSN： 0021-9673 1873-3778
Characterization of Thallium Bromide Detectors Made From Material Purified by the Filter Method Peer-reviewed

Toshiyuki Onodera, Keitaro Hitomi, Tsutomu Tada, Tadayoshi Shoji, Katsumi Mochizuki

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　60　(5)　3833-3836　2013/10

DOI： 10.1109/TNS.2013.2275171 　

ISSN： 0018-9499

eISSN： 1558-1578
化合物半導体TlBr結晶を用いたガンマ線検出器 Invited

人見啓太朗, 石井慶造

日本結晶成長学会誌　40　(3)　163-166　2013/10
Publisher: The Japanese Association for Crystal Growth (JACG)
DOI： 10.19009/jjacg.40.3_163 　

ISSN： 0385-6275

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Thallium bromide (TlBr) is a compound semiconductor attractive for fabrication of gamma-ray detectors. TlBr exhibits very high photon stopping power originating from its high atomic numbers (Ti: 81, Br: 35) and high density (7.56g/cm^3). Capacitive Frisch grid detectors and pixelated detectors were fabricated from TlBr crystals grown by the traveling molten zone method. The capacitive Frisch grid detectors exhibited an energy resolution of 1.7% FWHM for 662keV gamma-rays at -20℃. An energy resolution of 1.2% FWHM for 662keV was obtained from a pixelated anode of a TlBr detector operating at room temperature.
Advances in TlBr detector development Invited Peer-reviewed

Keitaro Hitomi, Tadayoshi Shoji, Keizo Ishii

JOURNAL OF CRYSTAL GROWTH　379　93-98　2013/09

DOI： 10.1016/j.jcrysgro.2013.03.002 　

ISSN： 0022-0248

eISSN： 1873-5002
Timing Performance of TlBr Detectors Peer-reviewed

Keitaro Hitomi, Tsutomu Tada, Toshiyuki Onodera, Tadayoshi Shoji, Seong-Yun Kim, Yuanlai Xu, Keizo Ishii

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　60　(4)　2883-2887　2013/08

DOI： 10.1109/TNS.2013.2268855 　

ISSN： 0018-9499
Adsorption properties and behavior of the platinum group metals onto a silica-based (Crea + TOA)/SiO2-P adsorbent from simulated high level liquid waste of PUREX reprocessing Peer-reviewed

Yuanlai Xu, Seong-Yun Kim, Tatsuya Ito, Tsutomu Tada, Keitaro Hitomi, Keizo Ishii

Journal of Radioanalytical and Nuclear Chemistry　297　(1)　41-48　2013/07

DOI： 10.1007/s10967-012-2314-9 　

ISSN： 0236-5731 1588-2780
TlBr Capacitive Frisch Grid Detectors Peer-reviewed

Keitaro Hitomi, Tsutomu Tada, Toshiyuki Onodera, Seong-Yun Kim, Yuanlai Xu, Tadayoshi Shoji, Keizo Ishii

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　60　(2)　1156-1161　2013/04

DOI： 10.1109/TNS.2012.2217155 　

ISSN： 0018-9499
A novel partitioning process for treatment of high level liquid waste using macroporous silica-based adsorbents Peer-reviewed

S. -Y. Kim, Y. Xu, T. Ito, Y. Wu, T. Tada, K. Hitomi, E. Kuraoka, K. Ishii

JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY　295　(2)　1043-1050　2013/02

DOI： 10.1007/s10967-012-1878-8 　

ISSN： 0236-5731
Study on Separation of Platinum Group Metals from High Level Liquid Waste Using Macroporous (MOTDGA-TOA)/SiO2-P Silica-based Absorbent

Tatsuya Ito, Seong-Yun Kim, Yuanlai Xu, Keitaro Hitomi, Keizo Ishii, Ryuji Nagaishi, Takaumi Kimura

GLOBAL2013　1504-1511　2013
Adsorption and separation behavior of yttrium and strontium in nitric acid solution by extraction chromatography using a macroporous silica-based adsorbent Peer-reviewed

Yuanlai Xu, Seong-Yun Kim, Tatsuya Ito, Kasane Nakazawa, Yoshihito Funaki, Tsutomu Tada, Keitaro Hitomi, Keizo Ishii

JOURNAL OF CHROMATOGRAPHY A　1263　28-33　2012/11

DOI： 10.1016/j.chroma.2012.09.036 　

ISSN： 0021-9673
Characterization of TlBrxCl1-x Crystals for Radiation Detectors Peer-reviewed

Toshiyuki Onodera, Keitaro Hitomi, Chikara Onodera, Tadayoshi Shoji, Katsumi Mochizuki

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　59　(4)　1559-1562　2012/08

DOI： 10.1109/TNS.2012.2200504 　

ISSN： 0018-9499

eISSN： 1558-1578
Study on selective separation of cesium from high level liquid waste using a macroporous silica-based supramolecular recognition absorbent Peer-reviewed

Y. Wu, S. -Y. Kim, D. Tozawa, T. Ito, T. Tada, K. Hitomi, E. Kuraoka, H. Yamazaki, K. Ishii

JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY　293　(1)　13-20　2012/07

DOI： 10.1007/s10967-012-1738-6 　

ISSN： 0236-5731

eISSN： 1588-2780
Digital pulse processing for planar TlBr detectors, optimized for ballistic deficit and charge-trapping effect Peer-reviewed

M. Nakhostin, K. Hitomi

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　675　47-50　2012/05

DOI： 10.1016/j.nima.2012.02.011 　

ISSN： 0168-9002
Equilibrium and kinetic studies of selective adsorption and separation for strontium using DtBuCH18C6 loaded resin Peer-reviewed

Yan Wu, Seong-Yun Kim, Daisuke Tozawa, Tatsuya Ito, Tsutomu Tada, Keitaro Hitomi, Etsushu Kuraoka, Hiromichi Yamazaki, Keizo Ishii

JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY　49　(3)　320-327　2012/03

DOI： 10.1080/00223131.2012.660022 　

ISSN： 0022-3131
Development of dosimeters using thallium bromide semiconductor detectors

Takami Jun, Hitomi Keitaro, Tada Tsutomu, Kim Seong-Yun, Xu Yuanlai, Ishii Keizo

Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan　2012　75-75　2012
Publisher: Atomic Energy Society of Japan
DOI： 10.11561/aesj.2012f.0.75.0 　
Characterization of TlBr capacitive Frisch grid detectors

Hitomi Keitaro, Tsutomu Tada, Onodera Toshiyuki, Xu Yuanlai Xu, Kim Seong-Yun, Shoji Tadayoshi, Ishii Keizo

Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan　2012　73-73　2012
Publisher: Atomic Energy Society of Japan
DOI： 10.11561/aesj.2012f.0.73.0 　
Separation and Recovery of Platinum Group Metals from High-level Radioactive Liquid Waste:-(3) Adsorption Properties by Silica-Supported Adsorbent in Radiation Field

Ito Tatsuya, Kim Seong-Yun, Xu Yuanlai, Hitomi Keitaro, Ishii Keizo, Nagaishi Ryuji, Kimura Takaumi

Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan　2012　567-567　2012
Publisher: Atomic Energy Society of Japan
DOI： 10.11561/aesj.2012f.0.567.0 　
Separation and Recovery of Platinum Group Metals from High-level Radioactive Liquid:-(4) Adsorption and Separation Behavior of PGMs using Two Novel Silica-Supported Adsorbents

Xu Yuanlai, Kim Seong-yun, Ito Tatsuya, Hitomi Keitaro, Tada Tsutomu, Ishii Keizo

Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan　2012　568-568　2012
Publisher: Atomic Energy Society of Japan
DOI： 10.11561/aesj.2012f.0.568.0 　
Characterization of thallium bromide chloride crystals for radiation detectors

T. Onodera, K. Hitomi, C. Onodera, T. Shoji, K. Mochizuki

IEEE Nuclear Science Symposium Conference Record　4524-4527　2012

DOI： 10.1109/NSSMIC.2011.6154728 　

ISSN： 1095-7863
Characterization of Thallium Bromide Crystals Purified by the Filter Method

T. Onodera, K. Hitomi, T. Tada, T. Shoji, K. Mochizuki

2012 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE RECORD (NSS/MIC)　4131-4134　2012

ISSN： 1082-3654
Semiconductor detectors fabricated from TIBr crystals Peer-reviewed

Keitaro Hitomi, Tsutomu Tada, Seong-Yun Kim, Yan Wu, Hiromichi Yamazaki, Tadayoshi Shoji, Keizo Ishii

Materials Research Society Symposium Proceedings　1341　111-117　2012

DOI： 10.1557/opl.2011.1112 　

ISSN： 0272-9172
Measurement of Electron Drift Mobility in TlBr Crystals

K. Hitomi, T. Tada, Y. Xu, S.-Y. Kim, H. Yamazaki, K. Ishii

CYRIC Annual Report 2010-2011　2010　39-42　2012
Publisher: Cyclotron and Radioisotope Center, Tohoku University
Study on Adsorption Behavior of Trivalent Rare Earths onto a Macroporous Silica-Based TODGA Adsorbent from High Level Liquid Waste

Y. Xu, E. Kuraoka, S. Usuda, S.-Y. Kim, K. Hitomi, T. Tada, H. Yamazaki, K. Ishii

CYRIC Annual Report 2010-2011　2010　88-92　2012
Publisher: Cyclotron and Radioisotope Center, Tohoku University
Study on Selective Separation and Recovery of Cesium and Strontium from High-level Liquid Waste (HLLW)

S.-Y. Kim, Y. Wu, D. Tozawa, T. Ito, Y. Xu, K. Hitomi, T. Tada, H. Yamazaki, K. Ishii

CYRIC Annual Report 2010-2011　82-87　2012
Investigation of an Optimum Clustering Condition for TlBr Detectors

T. Tada, K. Hitomi, Y. Xu, S.-Y. Kim, H. Yamazaki, K. Ishii

CYRIC Annual Report 2010-2011　2010　35-38　2012
Publisher: Cyclotron and Radioisotope Center, Tohoku University
K-mean clustering algorithm for processing signals from compound semiconductor detectors Peer-reviewed

Tsutomu Tada, Keitaro Hitomi, Yan Wu, Seong-Yun Kim, Hiromichi Yamazaki, Keizo Ishii

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　659　(1)　242-246　2011/12

DOI： 10.1016/j.nima.2011.09.007 　

ISSN： 0168-9002

eISSN： 1872-9576
Recent Development of TlBr Gamma-Ray Detectors Peer-reviewed

Keitaro Hitomi, Tsutomu Tada, Seong-Yun Kim, Yan Wu, Tomonobu Tanaka, Tadayoshi Shoji, Hiromichi Yamazaki, Keizo Ishii

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　58　(4)　1987-1991　2011/08

DOI： 10.1109/TNS.2011.2123115 　

ISSN： 0018-9499
Digital pulse processing and electronic noise analysis for improving energy resolutions in planar TlBr detectors Peer-reviewed

Tsutomu Tada, Keitaro Hitomi, Tomonobu Tanaka, Yan Wu, Seong-Yun Kim, Hiromichi Yamazaki, Keizo Ishii

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　638　(1)　92-95　2011/05

DOI： 10.1016/j.nima.2011.02.070 　

ISSN： 0168-9002
Development of a new two-dimensional position-sensitive detection based on resistive charge division and using CdTe detectors for a high-resolution semiconductor-based PET scanning Peer-reviewed

K. Ishii, Y. Kikuchi, K. Takahashi, K. Nakamura, S. Matsuyama, A. Terakawa, H. Yamazaki, K. Hitomi

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　631　(1)　138-143　2011/03

DOI： 10.1016/j.nima.2010.11.115 　

ISSN： 0168-9002
Characterization of Thallium Bromide Chloride Crystals for Radiation Detectors

T. Onodera, K. Hitomi, C. Onodera, T. Shoji, K. Mochizuki

2011 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC)　4524-4527　2011

ISSN： 1082-3654
半導体検出器用TIBr 結晶中の不純物元素のPIXE分析

多田勉, 人見啓太朗, 金聖潤, 山﨑浩道, 石井慶造

Heavy Ion Accelerator System Scientific Report 2010　24-30　2011
COMPUOUND SEMICONDUCTOR RADIATION DETECTORS

K. Hitomi, T. Tada, S.-Y. Kim, H. Yamazaki, K. Ishii

Proceedings of the 30th symposium on materials science and engineering research center of ion beam technology Housei University　5-8　2011
Study on Absorption of Radioactive Iodine in Nitric Acid Solution Using Hydroxylamine Nitrate Peer-reviewed

H. Tokuda, Y. Wu, T. Tada, K. Hitomi, S.-Y. Kim, H. Yamazaki, K. Ishii

Proc. of. GLOBAL2011　449199　1-4　2011
Selective Separation and Recovery of Cesium and Strontium from High Level Liquid Waste by Two Macroporous Silica-Based Supramolecular Recognition Absorbents Peer-reviewed

Y. Wu, D. Tozawa, T. Ito, S.-Y. Kim, K. Hitomi, T. Tada, E. Kuraoka, H. Yamazaki, K. Ishii

Proc. of. GLOBAL2011　391436　1-7　2011
Energy-discriminating X-ray computed tomography system utilizing a cadmium telluride detector Peer-reviewed

Eiichi Sato, Purkhet Abderyim, Toshiyuki Enomoto, Manabu Watanabe, Keitaro Hitomi, Kiyomi Takahasi, Shigehiro Sato, Akira Ogawae, Jun Onagawa

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　619　(1-3)　262-265　2010/07

DOI： 10.1016/j.nima.2009.10.087 　

ISSN： 0168-9002
Demonstration of iodine K-edge imaging by use of an energy-discrimination X-ray computed tomography system with a cadmium telluride detector Peer-reviewed

Abulajiang Abudurexiti, Masashi Kameda, Eiichi Sato, Purkhet Abderyim, Toshiyuki Enomoto, Manabu Watanabe, Keitaro Hitomi, Etsuro Tanaka, Hidezo Mori, Toshiaki Kawai, Kiyomi Takahashi, Shigehiro Sato, Akira Ogawa, Jun Onagawa

Radiological Physics and Technology　3　(2)　127-135　2010/07

DOI： 10.1007/s12194-010-0088-8 　

ISSN： 1865-0333
Digital pulse processing for planar TlBr detectors Peer-reviewed

M. Nakhostin, K. Hitomi, K. Ishii, Y. Kikuchi

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　615　(2)　242-244　2010/04

DOI： 10.1016/j.nima.2010.01.076 　

ISSN： 0168-9002
Recent development of TlBr gamma-ray detectors

Tomonobu Tanaka, Keitaro Hitomi, Tsutomu Tada, Seong-Yun Kim, Yan Wu, Tadayoshi Shoji, Hiromichi Yamazaki, Keizo Ishii

IEEE Nuclear Science Symposium Conference Record　3927-3931　2010

DOI： 10.1109/NSSMIC.2010.5874551 　

ISSN： 1095-7863
Energy-discrimination x-ray computed tomography system utilizing a scanning cadmium-telluride detector

Eiichi Sato, Ablajan Abduraxit, Toshiyuki Enomoto, Manabu Watanabe, Keitaro Hitomi, Kiyomi Takahashi, Shigehiro Sato, Akira Ogawa, Jun Onagawa

MEDICAL IMAGING 2010: PHYSICS OF MEDICAL IMAGING　7622　(2)　2010

DOI： 10.1117/12.843993 　

ISSN： 0277-786X
Study on Selective Separation of Cesium using a Macroporous Silica-based Supramolecular Recognition Absorbent

D. Tozawa, Y. Wu, T. Ito, T. Tada, K. Hitomi, E. KUraoka, S.Y. Kim, H. Yamazaki, K. Ishii

CYRIC Annual Report 2009　2009　127-131　2010
Publisher: Cyclotron and Radioisotope Center, Tohoku University
Improvement of Energy Resolutions for Planar TIBr Detectors Using the Digital Pulse Processing Method

T. Tada, T. Tanaka, S.Y. Kim, Y. Xu, K. Hitomi, H. Yamazaki, K. Ishii

CYRIC Annual Report 2009　2009　55-59　2010
Publisher: Cyclotron and Radioisotope Center, Tohoku University
Energy-Discriminating Gadolinium K-Edge X-ray Computed Tomography System Peer-reviewed

Hiroshi Matsukiyo, Manabu Watanabe, Eiichi Sato, Akihiro Osawa, Toshiyuki Enomoto, Jiro Nagao, Purkhet Abderyim, Katsuo Alzawa, Keitaro Hitomi, Etsuro Tanaka, Hidezo Mori, Toshiaki Kawai, Akira Ogawa, Kiyomi Takahashi, Shigehiro Sato, Jun Onagawa

JAPANESE JOURNAL OF APPLIED PHYSICS　49　(2)　027001　2010

DOI： 10.1143/JJAP.49.027001 　

ISSN： 0021-4922
Double-sided TlBr strip detectors for SPECT application

K. Hitomi, Y. Kikuchi, M. Nakhostin, T. Shoji, K. Ishii

European Jounal of Nuclear Medicine & Molecular Imaging　36　(2)　S171-S171　2009/10
Polarization Phenomena in TlBr Detectors Peer-reviewed

Keitaro Hitomi, Yohei Kikuchi, Tadayoshi Shoji, Keizo Ishii

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　56　(4)　1859-1862　2009/08

DOI： 10.1109/TNS.2009.2013349 　

ISSN： 0018-9499
Improvement of energy resolutions in TlBr detectors Peer-reviewed

Keitaro Hitomi, Yohei Kikuchi, Tadayoshi Shoji, Keizo Ishii

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　607　(1)　112-115　2009/08

DOI： 10.1016/j.nima.2009.03.129 　

ISSN： 0168-9002
Energy discriminating x-ray camera utilizing a cadmium telluride detector Peer-reviewed

Eiichi Sato, Abderyim Purkhet, Hiroshi Matsukiyo, Akihiro Osawa, Toshiyuki Enomoto, Manabu Wantanabe, Jiro Nagao, Seiichiro Nomiya, Keitaro Hitomi, Etsuro Tanaka, Toshiaki Kawai, Shigehiro Sato, Akira Ogawa, Jun Onagawa

OPTICAL ENGINEERING　48　(7)　076502-076502-7　2009/07

DOI： 10.1117/1.3183927 　

ISSN： 0091-3286
TlBr Semiconductor Detectors

HITOMI Keitaro

Medical Imaging Technology　27　(1)　9-9　2009
Publisher: The Japanese Society of Medical Imaging Technology
DOI： 10.11409/mit.27.9 　

ISSN： 0288-450X
Prototype of TlBr Detector Array for Ultra High Resolution PET

K. Ishii, K. Hitomi, M. Nakhostin, Y. Kikuch, M. Fujiwara, H. Yamazaki, S. Matsuyama, A. Terakawa

2008 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (2008 NSS/MIC), VOLS 1-9　2984-+　2009

DOI： 10.1109/NSSMIC.2008.4774135 　

ISSN： 1082-3654
High-speed photon-counting x-ray computed tomography system utilizing a multipixel photon counter

Eiichi Sato, Toshiyuki Enomoto, Manabu Watanabe, Keitaro Hitomi, Kiyomi Takahashi, Shigehiro Sato, Akira Ogawa, Jun Onagawa

Proceedings of SPIE - The International Society for Optical Engineering　7385　738525　2009

DOI： 10.1117/12.836012 　

ISSN： 0277-786X
Fabrication of TlBr strip detectors

Keitaro Hitomi, Youhei Kikuchi, Mohammad Nakhostin, Tadayoshi Shoji, Keizo Ishii

Proceedings of SPIE - The International Society for Optical Engineering　7449　74491D　2009

DOI： 10.1117/12.825794 　

ISSN： 0277-786X
Photoluminescence Analysis of TlBr Crystals for Radiation Detector Applications

Kentaro Hayakawa, Keitaro Hitomi, Tadayoshi Shoji, Chikara Onodera

2009 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-5　1647-+　2009

DOI： 10.1109/NSSMIC.2009.5402244 　

ISSN： 1082-3654
Current Status of Semiconductor Gamma-ray Detectors Fabricated from Thallium Bromide(TlBr) Crystals

K. Hitomi, Y. Kikuchi, T. Shoji, K. Ishii

Journal of the Japanese Association of Crystal Growth　35　(2)　118-122　2008/07

DOI： 10.19009/jjacg.35.2_118 　
TlBr gamma-ray spectrometers using the depth sensitive single polarity charge sensing technique Peer-reviewed

Keitaro Hitomi, Toshiyuki Onodera, Tadayoshi Shoji, Yukio Hiratate, Zhong He

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　55　(3)　1781-1784　2008/06

DOI： 10.1109/TNS.2008.924086 　

ISSN： 0018-9499
Investigation of pixelated TlBr gamma-ray spectrometers with the depth-sensing technique Peer-reviewed

Keitaro Hitomi, Toshiyuki Onodera, Tadayoshi Shoji, Zhong He

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　591　(1)　276-278　2008/06

DOI： 10.1016/j.nima.2008.03.086 　

ISSN： 0168-9002
Prototype of T1Br detector array for ultra high resolution PET Peer-reviewed

K. Ishii, K. Hitomi, M. Nakhostin, Y. Kikuch, M. Fujiwara, H. Yamazaki, S. Matsuyama, A. Terakawa

IEEE Nuclear Science Symposium Conference Record　3709-3710　2008

DOI： 10.1109/NSSMIC.2008.4774135 　

ISSN： 1095-7863
Energy-discriminating x-ray camera utilizing a cadmium telluride detector Peer-reviewed

Eiichi Sato, Purkhet Abderyim, Hiroshi Matsukiyo, Akihiro Osawa, Toshiyuki Enomoto, Manabu Watanabe, Jiro Nagao, Seichiro Nomiya, Keitaro Hitomi, Akira Ogawa, Shigehiro Sato, Toshio Ichimaru

HARD X-RAY, GAMMA-RAY, AND NEUTRON DETECTOR PHYSICS X　7079　2008

DOI： 10.1117/12.795480 　

ISSN： 0277-786X
Polarization Phenomena in TlBr Detectors

K.Hitomi, Y.Kikuchi, T.Shoji, K.Ishii

IEEE Nuclear Science Symposium, Medical Imaging Conference, Conference Record　181-184　2008
Energy-discriminating K-edge x-ray computed tomography system

Manabu Watanabe, Eiichi Sato, Purkhet Abderyim, Hiroshi Matsukiyo, Akihiro Osawa, Toshiyuki Enomoto, Jiro Nagao, Seiichiro Nomiya, Keitaro Hitomi, Akira Ogawa, Shigehiro Sato, Toshio Ichimaru

PENETRATING RADIATION SYSTEMS AND APPLICATIONS IX　7080　70800B　2008

DOI： 10.1117/12.795874 　

ISSN： 0277-786X
Evaluation of TlBr detectors with Tl electrodes

Keitaro Hitomi, Yohei Kikuchi, Tadayoshi Shoji, Keizo Ishii

HARD X-RAY, GAMMA-RAY, AND NEUTRON DETECTOR PHYSICS X　7079　70790J　2008

DOI： 10.1117/12.794381 　

ISSN： 0277-786X
X-ray computed tomography system using a multipixel photon counter

Eiichi Sato, Hiroshi Matsukiyo, Akihiro Osawa, Toshiyuki Enomoto, Manabu Watanabe, Jiro Nagao, Purkhet Abderyim, Seiichiro Nomiya, Keitaro Hitomi, Akira Ogawa, Shigehiro Sato

HARD X-RAY, GAMMA-RAY, AND NEUTRON DETECTOR PHYSICS X　7079　70790H　2008

DOI： 10.1117/12.795434 　

ISSN： 0277-786X
A method for suppressing polarization phenomena in TlBr detectors Peer-reviewed

Keitaro Hitomi, Tadayoshi Shoji, Yoshio Nlizeki

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　585　(1-2)　102-104　2008/01

DOI： 10.1016/j.nima.2007.11.012 　

ISSN： 0168-9002
Influence of zone purification process on TlBr crystals for radiation detector fabrication Peer-reviewed

Keitaro Hitomi, Toshiyuki Onodera, Tadayoshi Shoji

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　579　(1)　153-156　2007/08

DOI： 10.1016/j.nima.2007.04.028 　

ISSN： 0168-9002
Temperature dependence of spectroscopic performance of thallium bromide X- and gamma-ray detectors Peer-reviewed

Toshiyuki Onodera, Keitaro Hitomi, Tadayoshi Shoji

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　54　(4)　860-863　2007/08

DOI： 10.1109/TNS.2007.902703 　

ISSN： 0018-9499

eISSN： 1558-1578
Pixellated TlBr detectors with the depth sensing technique Peer-reviewed

Keitaro Hitomi, Toshiyuki Onodera, Tadayoshi Shoji, Zhong He

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　578　(1)　235-238　2007/07

DOI： 10.1016/j.nima.2007.05.113 　

ISSN： 0168-9002
Suppression of polarization phenomena in thallium bromide radiation detectors with illumination of infrared light

T. Onodera, K. Hitomi, T. Shoji

Proceedings of the 21st Workshop on Radiation Detectors and Their Uses　97-101　2007
Evaluation of LGSO scintillators with Si PIN photodiodes Peer-reviewed

Keitaro Hitomi, Toshiyuki Onodera, Tadayoshi Shoji, Yasushi Kuráta, Naoaki Shimura, Tatsuya Usui, Hiroyuki Ishibashi

IEEE Nuclear Science Symposium Conference Record　3　2033-2035　2007

DOI： 10.1109/NSSMIC.2007.4436551 　

ISSN： 1095-7863
Cerium bromide scintillation detectors Peer-reviewed

Toshiyuki Onodera, Keitaro Hitomi, Tadayoshi Shoji

IEEE Nuclear Science Symposium Conference Record　3　2182-2183　2007

DOI： 10.1109/NSSMIC.2007.4436584 　

ISSN： 1095-7863
TlBr gamma-ray spectrometers using the depth sensitive single polarity charge sensing technique Peer-reviewed

Keitaro Hitomi, Toshiyuki Onodera, Tadayoshi Shoji, Yukio Hiratate, Zhong He

IEEE Nuclear Science Symposium Conference Record　3　1908-1913　2007

DOI： 10.1109/NSSMIC.2007.4436529 　

ISSN： 1095-7863
Evaluation of the multi-pixel photon counters with inorganic scintillators

Keitaro Hitomi, Eiichi Sato, Seiichiro Nomiya, Tadayoshi Shoji

HARD X-RAY AND GAMMA-RAY DETECTOR PHYSICS IX　6706　67061C　2007

DOI： 10.1117/12.731704 　

ISSN： 0277-786X
Simple x-ray computed tomography system utilizing a cadmium telluride detector

Eiichi Sato, Seiichiro Nomiya, Keitaro Hitomi, Hideaki Onabe, Tadayoshi Shoji, Etsuro Tanaka, Toshiaki Kawai, Takashi Inoue, Akira Ogawa, Shigehiro Sato, Toshio Ichimaru, Kazuyoshi Takayama

HARD X-RAY AND GAMMA-RAY DETECTOR PHYSICS IX　6706　67060Y　2007

DOI： 10.1117/12.733420 　

ISSN： 0277-786X
High-dose-rate pulse x-ray detection using a multipixel photon counter

Eiichi Sato, Keitaro Hitomi, Seiichiro Nomiya, Hideaki Onabe, Tadayoshi Shoji, Etsuro Tanaka, Toshiaki Kawai, Takashi Inoue, Akira Ogawa, Shigehiro Sato, Kazuyoshi Takayama

PENETRATING RADIATION SYSTEMS AND APPLICATIONS VIII　6707　67070X　2007

DOI： 10.1117/12.733437 　

ISSN： 0277-786X

eISSN： 1996-756X
Fluorescent x-ray tomography system for atomic imaging

Eiichi Sato, Keitaro Hitomi, Seiichiro Nomiya, Etsuro Tanaka, Toshiaki Kawai, Takashi Inoue, Akira Ogawa, Mitsuru Izumisawa, Masanori Shozushima, Shigehiro Sato, Kazuyoshi Takayama

PENETRATING RADIATION SYSTEMS AND APPLICATIONS VIII　6707　67070S　2007

DOI： 10.1117/12.733458 　

ISSN： 0277-786X

eISSN： 1996-756X
Evaluation of LGSO scintillators with SiPIN photodiodes

Keitaro Hitomi, Toshiyuki Onodera, Tadayoshi Shoji, Yasushi Kurata, Naoaki Shimura, Tatsuya Usui, Hiroyuki Ishibashi

2007 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-11　3　2033-2035　2007

DOI： 10.1109/NSSMIC.2007.4436551 　

ISSN： 1082-3654
Cerium bromide scintillation detectors

Toshiyuki Onodera, Keitaro Hitomi, Tadayoshi Shoji

2007 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-11　3　2182-2183　2007

DOI： 10.1109/NSSMIC.2007.4436584 　

ISSN： 1082-3654
TlBr Gamma-Ray Spectrometers Using the Depth Sensitive Single Polarity Charge Sensing Technique Peer-reviewed

Keitaro Hitomi, Toshiyuki Onodera, Tadayoshi Shoji, Yukio Hiratate, Zhong He

2007 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-11　55　(3)　1908-+　2007

DOI： 10.1109/TNS.2008.924086 　

ISSN： 1082-3654
Spectroscopic performance and long-term stability of thallium bromide radiation detectors Peer-reviewed

Toshiyuki Onodera, Keitaro Hitomi, Tadayoshi Shoji

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　568　(1)　433-436　2006/11

DOI： 10.1016/j.nima.2006.06.016 　

ISSN： 0168-9002
Fabrication of indium iodide X- and gamma-ray detectors Peer-reviewed

Toshiyuki Onodera, Keitaro Hitomi, Tadayoshi Shoji

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　53　(5)　3055-3059　2006/10

DOI： 10.1109/TNS.2006.882749 　

ISSN： 0018-9499
Temperature Dependence of Spectroscopic Performance of Thallium Bromide X- and Gamma-Ray Detectors Peer-reviewed

Toshiyuki Onodera, Keitaro Hitomi, Tadayoshi Shoji

2006 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOL 1-6　3711-3714　2006

ISSN： 1082-3654
Spectroscopic performance of pixellated thallium bromide detectors Peer-reviewed

T Onodera, K Hitomi, T Shoji, Y Hiratate, H Kitaguchi

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　52　(5)　1999-2002　2005/10

DOI： 10.1109/TNS.2005.856876 　

ISSN： 0018-9499
Fabrication of indium iodide X- And gamma-ray detectors Peer-reviewed

Toshiyuki Onodera, Keitaro Hitomi, Tadayoshi Shoji

IEEE Nuclear Science Symposium Conference Record　3　1375-1378　2005

DOI： 10.1109/NSSMIC.2005.1596575 　

ISSN： 1095-7863
Fabrication of indium iodide X- and gamma-ray detectors Peer-reviewed

Toshiyuki Onodera, Keitaro Hitomi, Tadayoshi Shoji

2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5　1375-1378　2005

ISSN： 1082-3654
PVT growth of Cd1-xZnxTe(x similar to 0.04) films sensitive to radial rays Peer-reviewed

J Takahashi, K Mochizuki, K Hitomi, T Shoji

JOURNAL OF CRYSTAL GROWTH　269　(2-4)　448-453　2004/09

DOI： 10.1016/j.jcrysgro.2004.05.068 　

ISSN： 0022-0248
Growth of Cd1-xZnxTe (x similar to 0.04) films by hot-wall method and its evaluation Peer-reviewed

J Takahashi, K Mochizuki, K Hitomi, T Shoji

JOURNAL OF CRYSTAL GROWTH　269　(2-4)　419-424　2004/09

DOI： 10.1016/j.jcrysgro.2004.05.054 　

ISSN： 0022-0248
Pixellated thallium bromide detectors for gamma-ray spectroscopy and imaging Peer-reviewed

T Onodera, K Hitomi, T Shoji, Y Hiratate

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　525　(1-2)　199-204　2004/06

DOI： 10.1016/j.nima.2004.03.046 　

ISSN： 0168-9002

eISSN： 1872-9576
Spectroscopic performance of pixellated thallium bromide detectors

Toshiyuki Onodera, Keitaro Hitomi, Tadayoshi Shoji, Yukio Hiratate, Hiroshi Kitaguchi

IEEE Nuclear Science Symposium Conference Record　7　4448-4450　2004

ISSN： 1095-7863
Evaluation of pixellated HgI2 detectors

Keitaro Hitomi, Ling Jian Meng, Zhong He

IEEE Nuclear Science Symposium Conference Record　7　4456-4460　2004

ISSN： 1095-7863
Spectroscopic performance of pixellated thallium bromide detectors Peer-reviewed

T Onodera, K Hitomi, T Shoji, Y Hiratate, H Kitaguchi

2004 IEEE Nuclear Science Symposium Conference Record, Vols 1-7　4448-4450　2004

ISSN： 1082-3654
Pixellated thallium bromide X- and gamma-ray detectors Peer-reviewed

T Onodera, K Hitomi, T Shoji, Y Hiratate

2003 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-5　3428-3430　2004

ISSN： 1082-3654
Evaluation of pixellated HgI2 detectors

K Hitomi, LJ Meng, Z He

2004 IEEE Nuclear Science Symposium Conference Record, Vols 1-7　7　4456-4460　2004

ISSN： 1082-3654
Thallium lead iodide radiation detectors Peer-reviewed

K Hitomi, T Onodera, T Shoji, Y Hiratate

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　50　(4)　1039-1042　2003/08

DOI： 10.1109/TNS.2003.815351 　

ISSN： 0018-9499
Pixellated thallium bromide X- And gamma-ray detectors

T. Onodera, K. Hitomi, T. Shoji, Y. Hiratate

IEEE Nuclear Science Symposium Conference Record　5　3428-3430　2003

ISSN： 1095-7863
Thallium lead iodide radiation detectors

K Hitomi, T Onodera, T Shoji, Y Hiratate

2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3　485-488　2003

ISSN： 1082-3654
Bismuth tri-iodide crystal for nuclear radiation detectors Peer-reviewed

M Matsumoto, K Hitomi, T Shoji, Y Hiratate

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　49　(5)　2517-2520　2002/10

DOI： 10.1109/TNS.2002.803883 　

ISSN： 0018-9499
Thallium bromide optical and radiation detectors for X-ray and gamma-ray spectroscopy Peer-reviewed

K Hitomi, M Matsumoto, O Muroi, T Shoji, Y Hiratate

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　49　(5)　2526-2529　2002/10

DOI： 10.1109/TNS.2002.803851 　

ISSN： 0018-9499

eISSN： 1558-1578
Thallium bromide optical and radiation detectors for X- and gamma-ray spectroscopy Peer-reviewed

K Hitomi, M Matsumoto, O Muroi, T Shoji, Y Hiratate

2001 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORDS, VOLS 1-4　2406-2409　2002

ISSN： 1082-3654
Bismuth iodide (III) crystals for nuclear radiation detectors Peer-reviewed

M Matsumoto, K Hitomi, T Shoji, Y Hiratate

2001 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORDS, VOLS 1-4　2344-2347　2002

ISSN： 1082-3654
High-resolution CdTe radiation detectors with single-polarity charge sensing technique

R Tomie, K Hitomi, T Shoji, Y Hiratate

2001 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORDS, VOLS 1-4　4　2313-2315　2002

ISSN： 1082-3654
臭化タリウム(TlBr)結晶を用いた放射線検出器及び光検出器－放射線賞(奨励賞)を受賞して－

K. Hitomi

放射線　28　(1)　7-12　2002/01
Publisher:
ISSN： 0285-3604
Large-volume thallium bromide detectors for gamma-ray spectroscopy Peer-reviewed

K Hitomi, O Muroi, M Matsumoto, T Shoji, Y Hiratate

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　48　(6)　2313-2316　2001/12

DOI： 10.1109/23.983258 　

ISSN： 0018-9499

eISSN： 1558-1578
Characterization of thallium bromide crystals for radiation detector applications Peer-reviewed

K Hitomi, M Matsumoto, O Muroi, T Shoji, Y Hiratate

JOURNAL OF CRYSTAL GROWTH　225　(2-4)　129-133　2001/05

DOI： 10.1016/S0022-0248(01)00834-X 　

ISSN： 0022-0248
化合物半導体(TlBr, PbI₂, BiI₃)を用いた放射線検出器

庄司忠良, 人見啓太朗, 平舘幸男

放射線　27　(2)　63-72　2001/04
Publisher:
ISSN： 0285-3604
Recent progress in thallium bromide detectors for X- and gamma-ray spectroscopy Peer-reviewed

K Hitomi, O Muroi, M Matsumoto, R Hirabuki, T Shoji, T Suehiro, Y Hiratate

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　458　(1-2)　365-369　2001/02

DOI： 10.1016/S0168-9002(00)00883-4 　

ISSN： 0168-9002

eISSN： 1872-9576
Thallium bromide photodetectors for scintillation detection Peer-reviewed

K Hitomi, O Muroi, T Shoji, Y Hiratate, H Ishibashi, M Ishii

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　448　(3)　571-575　2000/07

DOI： 10.1016/S0168-9002(00)00290-4 　

ISSN： 0168-9002
X-ray detection characteristics of thallium bromide nuclear radiation detectors Peer-reviewed

K Hitomi, O Muroi, M Matsumoto, R Hirabuki, T Shoji, Y Hiratate

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　47　(3)　777-779　2000/06

DOI： 10.1109/23.856514 　

ISSN： 0018-9499

eISSN： 1558-1578
Promising blue sensitive photodetectors using thallium bromide crystals Peer-reviewed

K Hitomi, O Muroi, T Shoji, Y Hiratate

REVIEW OF SCIENTIFIC INSTRUMENTS　71　(1)　322-323　2000/01

DOI： 10.1063/1.1150149 　

ISSN： 0034-6748
Temperature characteristics of the radiation detector using the TlBr crystals Peer-reviewed

T Shoji, K Hitomi, O Muroi, T Suehiro, Y Hiratate

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　46　(6)　1934-1937　1999/12

DOI： 10.1109/23.819257 　

ISSN： 0018-9499

eISSN： 1558-1578
Room temperature X- and gamma-ray detectors using thallium bromide crystals Peer-reviewed

K Hitomi, O Muroi, T Shoji, T Suehiro, Y Hiratate

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　436　(1-2)　160-164　1999/10

DOI： 10.1016/S0168-9002(99)00614-2 　

ISSN： 0168-9002
Radiation damage effects by 25MeV protons and thermal annealing effects on thallium bromide nuclear radiation detectors Peer-reviewed

K Hitomi, T Shoji, T Suehiro, Y Hiratate

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　46　(3)　213-217　1999/06

DOI： 10.1109/23.775516 　

ISSN： 0018-9499
Improved spectrometric characteristics of thallium bromide nuclear radiation detectors Peer-reviewed

K Hitomi, T Murayama, T Shoji, T Suehiro, Y Hiratate

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT　428　(2-3)　372-378　1999/06

DOI： 10.1016/S0168-9002(99)00141-2 　

ISSN： 0168-9002

eISSN： 1872-9576
TlBr光検出器によるシンチレーション光の検出

人見啓太朗, 室井治, 庄司忠良, 平舘幸男, 石橋浩之, 石井満

放射線　25　(2)　83-88　1999/04
Publisher:
ISSN： 0285-3604
Response characteristics of the TlBr radiation detector as a function of the detector temperature

T. Shoji, K. Hitomi, T. Suehiro, Y. Hiratate

IEEE Nuclear Science Symposium and Medical Imaging Conference　2　774-775　1999
Publisher: IEEE
Characterization of radiation damage and thermal annealing effects on thallium bromide nuclear radiation detectors

K. Hitomi, T. Shoji, T. Suehiro, Y. Hiratate

IEEE Nuclear Science Symposium and Medical Imaging Conference　2　843-845　1999
Publisher: IEEE
X-ray detection characteristics of thallium bromide nuclear radiation detectors Peer-reviewed

K Hitomi, O Muroi, M Matsumoto, R Hirabuki, T Shoji, Y Hiratate

1999 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1-3　339-341　1999

ISSN： 1082-3654
Fabrication of a nuclear radiation detector using the PbI2 crystal and its response characteristics for gamma-rays Peer-reviewed

T Shoji, K Hitomi, T Tiba, T Suehiro, Y Hiratate

IEEE TRANSACTIONS ON NUCLEAR SCIENCE　45　(3)　581-584　1998/06

DOI： 10.1109/23.682452 　

ISSN： 0018-9499
Characteristics of PbI2 crystal for use as a gamma-ray detector Peer-reviewed

T Shoji, K Hitomi, T Tiba, T Suehiro, Y Hiratate

1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2　804-806　1998
Development of a simulation program using a Monte Carlo method for thallium bromide gamma-ray detectors

K. Hitomi, T. Shoji, T. Suehiro, Y. Hiratate

Memoirs of the Tohoku Institute of Technology, Ser. I　17　(17)　9-18　1997
Publisher:
ISSN： 0285-3817

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Misc. 14

Charge recombination dynamics of TlBr observed via transient absorption measurements

越水正典, 野上光博, 人見啓太朗, 室屋裕佐, 藤本裕, 浅井圭介

応用物理学会春季学術講演会講演予稿集(CD-ROM)　69th　2022

ISSN： 2436-7613
X-ray-, heavy-particle-, and neutron-induced thermoluminescence of Tb³⁺-doped Li₂O-Al₂O₃-B₂O₃ glasses

河村一朗, 川本弘樹, 藤本裕, 越水正典, 野上光博, 人見啓太朗, 浅井圭介, 岡田豪, 若林源一郎, 渡辺賢一, 柳田健之

日本セラミックス協会年会講演予稿集(Web)　2021　2021
Three-dimensional dose evaluation in proton therapy using a polymer-gel dosimeter

寺川貴樹, 若山雄大, 梶山愛, 牛島寛章, 服部祥尭, 田中香津生, 人見啓太朗, 野上光博

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　82nd　2021
Development of a 2-dimensional position-sensitive CdTe detector for PET application

久保信, 人見啓太朗, 野上光博, 寺川貴樹, 石井慶造

放射線(Web)　46　(1)　2020
Influence of thermal cycle on the low-temperature luminescence properties of TlBr crystals and its dependence on crystal growth

越水正典, 人見啓太朗, 野上光博, 藤本裕, 浅井圭介, 柳田健之, 青木徹

生体医歯工学共同研究拠点成果報告書　2019　2020
マイクロパターンガス検出器を用いた粒子線プロファイルモニターの多段ガス電子増幅による高感度化

鴫原健太, 寺川貴樹, 藤原充啓, 人見啓太朗, 細川響, 梶山愛, 藤瀬慶彦, 鳴海慶一郎, 長尾理那, 細川裕之, 野上光博, 牛島寛章, 若山雄太

日本原子力学会東北支部研究交流会講演要旨集　41st　2017
Effect of nitrate on corrosion of austenitic stainless steel in boiling nitric acid solution containing chromium ions (vol 53, pg 1332, 2016)

S. Hasegawa, S-Y Kim, T. Ebina, H. Tokuda, T. Ito, N. Nagano, K. Hitomi, K. Ishii

JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY　53　(9)　1454-1454　2016

DOI： 10.1080/00223131.2016.1143736 　

ISSN： 0022-3131

eISSN： 1881-1248
半導体検出器とシンチレーション検出器の基礎

人見啓太朗

光学　45　(8)　284-288　2016
Publisher: 一般社団法人日本光学会
ISSN： 0389-6625
Fabrication of Radiation Detectors using Thallium Bromide Chloride(TlBrxCl1-x) Crystals

NUMATA Tomoyuki, HITOMI Keitaro, ONODERA Toshiyuki, SHOJI Tadayoshi, HIRATATE Yukio

Ionizing radiation.　30　(2)　155-157　2004/04/01
Publisher: 応用物理学会放射線分科会
ISSN： 0285-3604
TlBr semiconductor radiation detectors

SHOJI Tadayoshi, HITOMI Keitaro, ONODERA Toshiyuki, HIRATATE Yukio

Ionizing radiation.　30　(1)　19-22　2004/01/01
Publisher: 応用物理学会放射線分科会
ISSN： 0285-3604
Fabrication of TlPbI3 Radiation Detectors

Memoirs of the Tohoku Institute of Technology. Ser.1, Science and engineering　(23)　7-11　2003/03
Publisher: 東北工業大学
ISSN： 0285-3817
Fabrication of Nuclear Radiation Detectors Usign Bismuth Iodide Crystals

MATSUMOTO Manabu, HITOMI Keitaro, SHOJI Tadayoshi, HIRATATE Yukio

Ionizing radiation.　28　(1)　39-43　2002/01/01
Publisher: 応用物理学会放射線分科会
ISSN： 0285-3604
Charge Transport Properties of TlBr Radiation Detectors

MATSUMOTO M., HITOMI K., MUROI O., SHOJI T., HIRATATE Y.

27　(1)　35-40　2001/01/01
Publisher: 応用物理学会放射線分科会
ISSN： 0285-3604
Charge Carrier Transport Properties of Thallium Bromide Crystal for Nuclear Radiation Detector Application

Memoirs of the Tohoku Institute of Technology. Ser.1, Science and engineering　(20)　1-4　2000/03
Publisher: 東北工業大学
ISSN： 0285-3817

Show all ︎Show first 5

Presentations 99

TlBr半導体の結晶性および二次元キャリア輸送特性の比較

須貝優介, 長谷川創大, 渡辺賢一, 人見啓太朗, 野上光博

第71回応用物理学会春季学術講演会　2024
Radiation Sensing Using Thallium Bromide Crystals Invited

Keitaro Hitomi, Mitsuhiro Nogami

The 30th International Display Workshops　2023/12/07
Study on conditioning effect of TlBr semiconductor detectors with gold electrodes

S. Hasegawa, K. Watanabe, K. Hitomi, M. Nogami, Y. Sugai

2023 IEEE Nuclear Science Symposium, Medical Imaging Conference, and Room-Temperature Semiconductor Detector Conference　2023/11/09
Experimental Evaluation of Novel a 4π Field of View Gamma-ray Imaging Method

Y. Kitayama, M. Nogami, K. Hitomi

2023 IEEE Nuclear Science Symposium, Medical Imaging Conference, and Room-Temperature Semiconductor Detector Conference　2023/11/08
Crystal quality evaluation of a large TlBr crystal using neutron Bragg-dip imaging

K. Watanabe, S. Hasegawa, Y. Sugai, M. Nogami, K. Hitomi, S. Maeda, H. Onabe

2023 IEEE Nuclear Science Symposium, Medical Imaging Conference, and Room-Temperature Semiconductor Detector Conference　2023/11/08
Analysis of Recombination Kinetics of Electron-Hole Pairs in TlBr Crystals Using Pulsed Electron Beams of Different Intensities

M. Koshimizu, Y. Muroya, M. Nogami, K. Hitomi

2023 IEEE Nuclear Science Symposium, Medical Imaging Conference, and Room-Temperature Semiconductor Detector Conference　2023/11/07
Characterization of Thallium Bromide Gamma-Ray Detectors for Boron Neutron Capture Therapy

K. Hitomi, M. Nogami, K. Watanabe, T. Onodera, H. Tanaka, K. Ishii

2023 IEEE Nuclear Science Symposium, Medical Imaging Conference, and Room-Temperature Semiconductor Detector Conference　2023/11/07
X-ray imaging using single crystal diamond 80μm pitch pixel detector

K. Toyoda, K. Koyama, S.-W. Kim, T. Miyake, J. Nishizawa, K. Takagi, H. Kase, T. Takagi, K. Tabata, T. Terao, H. Morii, A. Koike, K. Hitomi, T. Aoki

2023 IEEE Nuclear Science Symposium, Medical Imaging Conference, and Room-Temperature Semiconductor Detector Conference　2023/11/06
ヘテロエピタキシャルダイヤモンド両面ストリップ検出器の製作

人見啓太朗, 小山浩司, 小野寺敏幸, 野上光博, 金聖祐

第70回応用物理学会春季学術講演会　2023/03/16
TlBrピクセル検出器実装評価システム開発

豊川秀訓, 人見啓太朗, 野上光博, 小野寺敏幸, 池田博一, 久保信, 末永敦士, 尾鍋秀明

第84回応用物理学会秋季学術講演会　2023
臭化タリウム半導体検出器のコンディショニング効果の評価

長谷川創大, 渡辺賢一, 須貝優介, 人見啓太朗, 野上光博

第84回応用物理学会秋季学術講演会　2023
TlBr結晶の二次元キャリア輸送特性評価システムに関する検討

須貝優介, 長谷川創大, 渡辺賢一, 人見啓太朗, 野上光博

第84回応用物理学会秋季学術講演会　2023
プラズマ処理したTl電極TlBr放射線検出器の初期特性評価

野島太郎, 野上光博, 小野寺敏幸, 人見啓太朗

第84回応用物理学会秋季学術講演会　2023
TlBr半導体検出器の移動度二次元分布計測システムの開発

渡辺賢一, 須貝優介, 長谷川創大, 野上光博, 人見啓太朗

日本原子力学会 2023年秋の大会　2023
Fabrication of 2-cm Thick TlBr Detectors

K. Hitomi, S. Maeda, M. Nogami, C. Ito, K. Watanabe

2022 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room Temperature Semiconductor Detector Conference　2022/11/07
小動物を用いた臨床前陽子線治療研究のための水相対阻止能導出精度に関する低エネルギー陽子線CTとX線CTの比較

寺川貴樹, 細川響, 鴫原健太, 梶山愛, 藤瀬慶彦, 長尾理那, 鳴海慶一郎, 細川裕之, 野上光博, 藤原充啓, 和田成一, 長野宣道, 人見啓太朗

第83回応用物理学会秋季学術講演会　2022/09/22
ピコ秒からマイクロ秒に至るTlBrの電荷再結合ダイナミク

越水正典, 野上光博, 人見啓太朗, 室屋裕佐

第83回応用物理学会秋季学術講演会　2022/09/22
TlBrの結晶育成方向の結晶方位分布の観察

渡辺賢一, 人見啓太朗, 野上光博, 前田茂貴, 尾鍋秀明

第83回応用物理学会秋季学術講演会　2022/09/21
ヘテロエピタキシャルダイヤモンド放射線検出器の作製

入江優雅, 人見啓太朗, 野上光博, 中山隼, 金聖祐, 小山浩司, サハニロイチャンドラ, 嘉数誠

第83回応用物理学会秋季学術講演会　2022/09/20
TlBr検出器の連続動作特性評価

人見啓太朗, 野上光博, 渡辺賢一, 前田茂貴, 小野寺敏幸, 石井慶造

第83回応用物理学会秋季学術講演会　2022/09/20
ピクセル型臭化タリウム半導体検出器の有感体積評価

長谷川創大, 渡辺賢一, 人見啓太朗, 野上光博

第83回応用物理学会秋季学術講演会　2022/09/20
ガンマ線三次元影を用いた全方向イメージング技術の検討

北山佳治, 野上光博, 人見啓太朗

第83回応用物理学会秋季学術講演会　2022/09/20
斜方立方八面体型指向性検出器の基礎検討

野上光博, 北山佳治, 人見啓太朗, 高田英治, 鳥居建男, 石井慶造

日本原子力学会 2022年秋の大会　2022/09/08
プレス成型によるTlBr結晶の作製（3）

小野寺敏, 人見啓太朗

第69回応用物理学会春季学術講演会　2022/03/24
TlBrガンマ線検出器の位置分解能向上のための検討

野上光博, 人見啓太朗, 小野寺敏幸, 椿山邦見, 渡辺賢一, 山端峻, 石井慶造

第69回応用物理学会春季学術講演会　2022/03/24
TlBr結晶の中性子回折イメージとEBSD像の比較

渡辺賢一, 人見啓太朗, 野上光博, 前田茂貴, 伊藤主税, 丹野敬嗣, 尾鍋秀明

第69回応用物理学会春季学術講演会　2022/03/24
過渡吸収で観測したTlBrの電荷再結合ダイナミクス

越水正典, 野上光博, 人見啓太朗, 室屋裕佐, 藤本裕, 浅井圭介

第69回応用物理学会春季学術講演会　2022/03/24
錯体を用いた再結晶法によるTlBrの精製その２

野島太郎, 小野寺敏幸, 人見啓太朗

第69回応用物理学会春季学術講演会　2022/03/22
TlBrガンマ線検出器を用いたチェレンコフ光子と電荷の同時読み出し

金正勲, 島添健次, 高橋浩之, 人見啓太朗, 野上光博

第69回応用物理学会春季学術講演会　2022/03/22
TlBr検出器を用いた加速器中性子による478 keV即発ガンマ線の検

人見啓太朗, 野上光博, 渡辺賢一, 小野寺敏幸, 田中浩基, 石井慶造

第69回応用物理学会春季学術講演会　2022/03/22
X-ray FPDへの応用に向けた薄膜TlBr検出器の基礎評価(2)

野上光博, 人見啓太朗, 金正勲, 島添健次, 石井慶造

日本原子力学会 2022年春の年会　2022/03/17
Timing resolution of TlBr and TlBr-TlCl PET detectors based on Cerenkov radiation measurement

F. Nishikido, K. Hitomi, M. Nogami, H. G. Kang, T. Yamaya

The 28th International Conference on Room-Temperature Semiconductor Detectors　2021/10/22
Optimization of TlBrCl Crystal for Cherenkov Photon Time Resolution

C. Kim, K. Shimazoe, H. Takahashi, K. Hitomi, M. Nogami

The 28th International Conference on Room-Temperature Semiconductor Detectors　2021/10/20
Characterization of long-term stability of thallium bromide gamma-ray detectors

K. Hitomi, M. Nogami, T. Onodera, K. Watanabe, K. Ishii

The 28th International Conference on Room-Temperature Semiconductor Detectors　2021/10/20
Spatial Resolution of X-ray Imaging using TlBr Detector with Silver Electrodes

K. Toyoda, K. Takagi, H. Kase, T. Takagi, K. Tabata, T. Terao, H. Morii, A. Koike, T. Aoki, M. Nogami, K. Hitomi

The 28th International Conference on Room-Temperature Semiconductor Detectors　2021/10/19
TlBr結晶を用いた放射線検出器開発 Invited

人見啓太朗

第82回応用物理学会秋季学術講演会　2021/09/11
Development of capacitive Frisch grid TlBr detectors with reversible electrode design

M. Nogami, K. Hitomi, T. Onodera, K. Watanabe, K. Matsumoto, S. Kubo, N. Kimura, K. Ishii

The 27th International Symposium on Room-Temperature Semiconductor Detectors　2020/11/03
Development of thallium halide gamma-ray detectors

K. Hitomi, M. Nogami, T. Onodera, K. Watanabe, H. Tanaka, S. Kubo, N. Kimura, K. Ishii

The 27th International Conference on Room-Temperature Semiconductor Detectors　2020/11/02
Characterization of 1-cm thick Thallium Bromide Gamma-Ray Detectors Invited

K. Hitomi, M. Nogami, T. Onodera, K. Watanabe, K. Matsumoto, J. Lee, K. Ishii

26th International Symposium on Room-Temperature Semiconductor Detectors　2019/10/31
Crystalline evaluation of TlBr semiconductor detectors using energy-resolved neutron imaging

K. Watanabe, K. Matsumoto, A. Uritani, Y. Kiyanagi, K. Hitomi, M. Nogami, H. Sato, W. Kockelma

26th International Symposium on Room-Temperature Semiconductor Detectors　2019/10/31
Photon counting X-ray imager by dicect charge conversiton with TlBr, CdTe semiconductors

T. Aoki, K. Takagi, A. Koike, T. Takagi, K. Hitomi

26th International Symposium on Room-Temperature Semiconductor Detectors　2019/10/30
Development of Thallium Bromide Gamma-Ray Detectors for Intense Radiation Fields

M. Nogami, K. Hitomi, T. Torii, Y. Sato, Y. Tanimura, K. Kawabata, Y. Furuta, H. Usami, T. Onodera, N. Kimura, S. Kubo, K. Watanabe, S. - Y. Kim, T. Ito, K. Ishii, K. Shimazoe, H. Takahashi

26th International Symposium on Room-Temperature Semiconductor Detectors　2019/10/29
Basic Study on New Configurations for Thallium Bromide Detectors

K. Matsumoto, K. Watanabe, K. Hitomi, N. Nagano, M. Nogami, S. Yoshihashi, A. Yamazaki, A. Uritani

26th International Symposium on Room-Temperature Semiconductor Detectors　2019/10/29
Partial Recovery of Pixellated Thallium Bromide from Polarization through Sustained Reverse-Polarity Biasing

E. Hall, K. Hitomi, Z. He

26th International Symposium on Room-Temperature Semiconductor Detectors　2019/10/29
Development of Thallium Bromide Detectors for Compton Imaging International-presentation Invited

K. Hitomi, M. Nogami, N. Nagano, T. Onodera, K. Watanabe, M. Matsumura, S.-Y. Kim, T. Ito, K. Ishii

2017 IEEE Nuclear Science Symposium, Medical Imaging Conference, and 24th Symposium on Room-Temperature X- and Gamma-Ray Detectors　2017/10/25
高レベル放射性廃液中からのルテニウムの選択的分離・回収及びその利用 (2)硫黄含有アミド酸型抽出剤担持吸着材の吸着特性

伊藤辰也, 金聖潤, 長野宣道, 人見啓太朗

日本原子力学会2017年春の年会　2017/03/27
Flinak溶融塩精製のための一方向凝固法適用性評価

宍戸博紀, 小野寺敏幸, 人見啓太朗, 遊佐訓孝, 橋爪秀利

日本原子力学会2017年春の年会　2017/03/27
液体窒素温度におけるTlBr半導体検出器のガンマ線応答

前畑京介, 小峰良太, 善本翔大, 伊豫本直子, 尾鍋秀明, 人見啓太朗, 小野寺敏幸

日本原子力学会2017年春の年会　2017/03/27
非破壊検査装置への応用を目指した臭化タリウム(TlBr)検出器の基礎特性評価

高坂充, 人見啓太朗, 長野宣道, 小野寺敏幸, 金聖潤, 伊藤辰也, 木村乃久, 砂庭広季, 石井慶造

日本原子力学会2017年春の年会　2017/03/27
三次元相互作用位置情報を用いた9ピクセル型TlBr検出器の評価

砂庭広季, 人見啓太朗, 長野宣道, 小野寺敏幸, 金聖潤, 伊藤辰也, 木村乃久, 高坂充, 石井慶造

日本原子力学会2017年春の年会　2017/03/27
液体窒素で動作するTlBr半導体検出器の検出信号読み出し回路

小峰良太, 善本翔大, 伊豫本直子, 前畑京介, 尾鍋秀明, 人見啓太朗, 小野寺敏幸

第64回応用物理学会春季学術講演会　2017/03/14
ピクセル型TlBr半導体検出器を用いたコンプトンカメラの開発

松村基広, 渡辺賢一, 山﨑淳, 吉橋幸子, 瓜谷章, 砂場広季, 長野宣道, 人見啓太朗

第64回応用物理学会春季学術講演会　2017/03/14
Recent Results from Pixelated TlBr Detectors with Tl Electrodes Operated at Room- Temperature International-presentation

C. Leak, W. Koehler, S. O'Neal, Z. He, K. Hitomi

The 23rd International Symposium on Room-Temperature Semiconductor Detectors　2016/10/29
Basic Study of a Compton Scattering Camera Using a Pixelated TlBr Detector International-presentation

M. Matsumura, K. Watanabe, A. Yamazaki, S. Yoshihashi, A. Uritani, H. Sunaba, N. Nagano, K. Hitomi

The 23rd International Symposium on Room-Temperature Semiconductor Detectors　2016/10/29
Growth of TlBr Crystals by the Vertical Bridgman Method and the Traveling Molten Zone Method for Gamma-Ray Detector Applications International-presentation

K. Hitomi, T. Onodera, N. Nagano, K. Watanabe, M. Matsumura, S.-Y. Kim, T. Ito, K. Ishii

The 23rd International Symposium on Room-Temperature Semiconductor Detectors　2016/10/29
ピクセル型臭化タリウム半導体検出器を用いたコンプトンカメラの研究

松村基広, 山崎淳, 渡辺賢一, 吉橋幸子, 瓜谷章, 砂庭広季, 長野宣道, 人見啓太朗

第77回応用物理学会秋季学術講演会　2016/09/13
三次元相互作用位置情報を用いたTlBr検出器のエネルギー分解能改善

砂庭広季, 人見啓太朗, 長野宣道, 木村乃久, 小野寺敏幸, 伊藤辰也, 金聖潤, 石井慶造

日本原子力学会2016年秋の大会　2016/09/07
波形解析による臭化タリウム検出器のエネルギー分解能改善

人見啓太朗, 長野宣道, 小野寺敏幸, 伊藤辰也, 金聖潤, 石井慶造

第53回アイソトープ・放射線研究発表会　2016/07/06

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発表日7/7、東京大学弥生講堂
Fabrication and Evaluation of Orthogonal-Strip TlBr Gamma-Ray Detectors International-presentation

K. Hitomi, N. Nagano, T. Onodera, T. Ito, S.-Y. Kim, K. Ishii

2016 IEEE Symposium on Radiation Measurements and Applications　2016/05/22

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2016/5/25発表 University of California, Berkeley
Study on Tolerance of TlBr Semiconductor Detectors to Gamma-Ray Irradiation International-presentation

M. Matumura, K. Watanabe, A. Yamazaki, A. Uritani, N. Nagano, K. Hitomi

2016 IEEE Symposium on Radiation Measurements and Applications　2016/05/22

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2016/5/26 University of California, Berkeley
位置敏感型TlBr検出器の製作と評価

人見啓太朗, 長野宣道, 小野寺敏幸, 伊藤辰也, 金聖潤, 石井慶造

日本原子力学会「2016年春の年会」　2016/03/26

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東北大学川内キャンパス 2016年3月26日発表
垂直TMZ法を用いたTlBr結晶の育成及びTlBr検出器の評価

小野寺敏幸, 人見啓太朗, 庄司忠良

第63回応用物理学会春季学術講演会　2016/03/19

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2016年3月21日発表東工大大岡山キャンパス
Tl電極の臭化タリウム半導体検出器の温度特性

松村基広, 山﨑淳, 渡辺賢一, 瓜谷章, 長野宣道, 人見啓太朗

第63回応用物理学会春季学術講演会　2016/03/19

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2016年3月21日発表東工大大岡山キャンパス
3 x 3ピクセル電極を有するTlBr検出器の製作

人見啓太朗, 長野宣道, 小野寺敏幸, 伊藤辰也, 金聖潤, 石井慶造

第63回応用物理学会春季学術講演会　2016/03/19

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2016年3月21日発表東工大大岡山キャンパス
TlBr結晶の蛍光およびシンチレーション特性

越水正典, 人見啓太朗, 柳田健之, 藤本裕, 浅井圭介

第63回応用物理学会春季学術講演会　2016/03/19

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2016年3月21日発表東工大大岡山キャンパス
Development of position-sensitive TlBr gamma-ray detectors International-presentation

Keitaro Hitomi, Nobumichi Nagano, Toshiyuki Onodera, Tatsuya Ito, Seong-Yun Kim, Keizo Ishii

First International Symposium on Radiation Detectors and Their Uses　2016/01/18

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2016年1月21日発表 KEK
Study on the effects of exposure of TlBr semiconductor detector to gamma-ray International-presentation

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

First International Symposium on Radiation Detectors and Their Uses　2016/01/18

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2016年1月19日発表 KEK
Development of TlBr Gamma-Ray Detectors with Single Polarity Charge Sensing Configurations International-presentation

K. Hitomi, N. Nagano, T. Onodera, C. Disch, S.-Y. Kim, T. Ito, K. Ishii

2015 IEEE Nuclear Science Symposium, Medical Imaging Conference and 22nd International Symposium on Room-Temperature Semiconductor X-Ray and Gamma-ray Detectors　2015/10/31

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Thursday, Nov. 5 16:30 ~ Town and Country Hotel
Novel Digital Signal Processing Technique for TlBr Semiconductor Detector International-presentation

M. Matsumura, K. Watanabe, A. Yamazaki, A. Uritani, K. Hitomi

2015 IEEE Nuclear Science Symposium, Medical Imaging Conference, and 22nd International Symposium on Room-Temperature Semiconductor X-Ray and Gamma-Ray Detectors　2015/10/31

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Wednesday, Nov. 4 Town and Country Hotel
SPECT装置への応用を目指した新しい化合物半導体検出器の開発

人見啓太朗, 長野宣道, 伊藤辰也, 金聖潤, 石井慶造, 小野寺敏幸

第43回日本放射線技術学会秋季学術大会　2015/10/08

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2015年10月9日発表金沢市文化ホール
縦型TMZ法を用いたTlBr結晶の育成(II)

小野敏幸, 人見啓太朗, 庄司忠良

第76回応用物理学会秋季学術講演会　2015/09/13

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2015年9月13日発表名古屋国際会議場
両面ストリップ型TlBr検出器の製作

人見啓太朗, 長野宣道, 小野寺敏幸, 伊藤辰也, 金聖潤, 石井慶造

第76回応用物理学会秋季学術講演会　2015/09/13

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2015年9月15日発表名古屋国際会議場
臭化タリウム半導体検出器の耐放射線性

松村基広, 山﨑淳, 渡辺賢一, 瓜谷章, 長野宣道, 人見啓太朗

第76回応用物理学会秋季学術講演会　2015/09/13

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2015年9月15日発表名古屋国際会議場
TlBr検出器を用いたガンマ線CTの検討

長野宣道, 人見啓太朗, 小野寺敏幸, 伊藤辰也, 金聖潤, 石井慶造

第76回応用物理学会秋季学術講演会　2015/09/13

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2015年9月15日発表名古屋国際会議場
TlBrガンマ線検出器の信号処理法開発

長野宣道, 人見啓太朗, 伊藤辰也, 金聖潤, 石井慶造, 小野寺敏幸

日本原子力学会「2015年秋の大会」　2015/09/09

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9月9日発表静岡大学静岡キャンパス
TlBrを用いたX線検出器の開発II

人見啓太朗, 長野宣道, 伊藤辰也, 金聖潤, 石井慶造, 小野寺敏幸

日本原子力学会「2015年秋の大会」　2015/09/09

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9月9日発表静岡大学静岡キャンパス
高純度化合物半導体を用いた放射線検出器

日本学術振興会素材プロセシング第69委員会第２分科会(新素材関連技術)[第69回]研究会　2015/07/24
臭化タリウムガンマ線検出器システムの製作

人見啓太朗, 木村乃久, 長野宣道, 小野寺敏幸, 金聖潤, 石井慶造

第52回アイソトープ・放射線研究発表会　2015/07/08

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7/8発表
臭化タリウム半導体検出器の純化と特性評価

日本学術振興会放射線化学とその応用第186委員会第15回研究会「放射線検出器材料と不純物・欠陥」　2015/05/14
TlBrを用いたX線検出器の開発

人見啓太朗, 小野寺敏幸, 金聖潤, 石井慶造

日本原子力学会「2015年春の年会」　2015/03/20

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3/21日発表茨城大学日立キャンパス
TlBr検出器の電子正孔対生成エネルギーの測定Ⅱ

人見啓太朗, 小野寺敏幸, 金聖潤, 庄司忠良, 石井慶造

第62回応用物理学会春季学術講演会　2015/03/11

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3月13日発表東海大学湘南キャンパス
Characterization of TlBr Gamma-Ray Detectors International-presentation

K. Hitomi, T. Onodera, S.-Y. Kim, T. Shoji, K. Ishii

2014 IEEE Nuclear Science Symposium, Medical Imaging Conference and 21st Symposium on Room-Temperature Semiconductor X-Ray and Gamma-Ray Detectors　2014/11/08

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11月13日発表 Washington State Convention Center, Seattle, WA, USA
TlBr検出器の電子正孔対生成エネルギーの測定

人見啓太朗, 小野寺敏幸, 金聖潤, 庄司忠良, 石井慶造

第75回応用物理学会秋季学術講演会　2014/09/17

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9月17日発表北海道大学札幌キャンパス
臭化タリウム半導体検出器の再処理施設への適用に関する検討(Ⅲ)

木村乃久, 人見啓太朗, 金聖潤, 石井慶造

日本原子力学会「2014年秋の大会」　2014/09/08

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9月8日発表京都大学吉田キャンパス
コンプトンカメラ用ピクセル型 TlBr 検出器の開発 II

人見啓太朗, 小野寺敏幸, 木村乃久, 金聖潤, 庄司忠良, 石井慶造

日本原子力学会「2014年秋の大会」　2014/09/08

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9月8日発表京都大学吉田キャンパス
ピクセル型TlBr検出器の評価

人見啓太朗, 小野寺敏幸, 金聖潤, 庄司忠良, 石井慶造

第51回アイソトープ・放射線研究発表会　2014/07/07

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7月7日発表東京大学弥生講堂
Noise and detector performance studies of TlBr and (Cd, Zn)Te at room temperature with various digital pulse shapers International-presentation

Markus Dambacher, Keitaro Hitomi, Christian Disch, Alex Fauler, Michael Fiederle

2014 Symposium on Radiation Measurements and Applications (SORMA XV)　2014/06/09

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発表日2014年6月11日
臭化タリウム半導体検出器の再処理施設への適用に関する検討Ⅱ

木村乃久, 人見啓太朗, 金聖潤, 石井慶造

日本原子力学会「2014年春の年会」　2014/03/26
ピクセル型TlBr検出器に於ける2ピクセルイベントの評価

人見啓太朗, 小野寺敏幸, 金聖潤, 庄司忠良, 石井慶造

第61回応用物理学会春季学術講演会　2014/03/17
Development of Pixelated TlBr Detectors International-presentation

K. Hitomi, T. Onodera, S.-Y. Kim, Y. Xu, T. Shoji, K. Ishii

2013 IEEE Nuclear Science Symposium, Medical Imaging Conference & Workshop on Room-Temperature Semiconductor X-Ray and Gamma-Ray Detectors　2013/10/27
硝酸溶液中でのR-SUS304ULC鋼の腐食に与えるCrの酸化還元挙動と沸騰の影響

長谷川聡, 蝦名哲成, 徳田玄明, 稲熊正彦, 徐源来, 人見啓太朗, 金聖潤, 石井慶造

日本原子力学会「2013年秋の大会」　2013/09/03

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9/4発表
臭化タリウム半導体検出器の再処理施設への適用に関する検討

木村乃久, 人見啓太朗, 金聖潤, 徐源来, 石井慶造

日本原子力学会「2013年秋の大会」　2013/09/03

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9/5発表
コンプトンカメラ用ピクセル型TlBr検出器の開発

人見啓太朗, 木村乃久, 金聖潤, 徐源来, 石井慶造, 小野寺敏幸

日本原子力学会「2013年秋の大会」　2013/09/03
Fabrication and Characterization of Pixelated TlBr detectors International-presentation

K. Hitomi, T. Onodera, S.Y. Kim, Y. Xu, T. Shoji, K. Ishii

15th International Workshop on Radiation Imaging Detectors　2013/06/23

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June 26th, 2013 発表
Timing Performance of TlBr Detectors International-presentation

K. Hitomi, T. Tada, T. Onodera, T. Shoji, S.-Y. Kim, Y. Xu, K. Ishii

IEEE 2012 Nuclear Science Symposium, Medical Imaging Conferenc & Workshop on Room-Temperature Semiconductor X-Ray and Gamma-Ray Detectors　2012/10/29
Measurement of Charge Transport Properties of TlBr Crystals Using a Digital Signal Processing Technique International-presentation

T. Tada, K. Hitomi, T. Onodera, T. Shoji, Y. Xu, S.-Y. Kim, K. Ishii

IEEE 2012 Nuclear Science Symposium, Medical Imaging Conferenc & Workshop on Room-Temperature Semiconductor X-Ray and Gamma-Ray Detectors　2012/10/29
Capacitive Frishc Grid型TlBr検出器のエネルギー分解能評価

人見啓太朗, 多田勉, 小野寺敏幸, 金聖潤, 徐源来, 庄司忠良, 石井慶造

第73回応用物理学会学術講演会　2012/09/11
Thick TlBr detectors for gamma-ray spectroscopy International-presentation

K. Hitomi, T. Tada, S.-Y. Kim, Y. Xu, T. Onodera, T. Shoji, H. Yamazaki, K. Ishii

SPIE Conference on Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XIV　2012/08/13
TlBr Capacitive Frisch Grid Detectors International-presentation

K. Hitomi, T. Tada, S.-Y. Kim, Y. Xu, T. Onodera, T. Shoji, H. Yamazaki, K. Ishii

2012 IEEE Symposium on Radiation Measurements and Applications　2012/05/14

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Industrial Property Rights 3

放射線検出器及びこれを備えた装置

Property Type: Patent
半導体放射線検出器及び放射線検出装置

Property Type: Patent
臭素リッチな臭化タリウムの単結晶の製造方法

Property Type: Patent

Research Projects 25

超高感度半導体検出器を用いたSPECT装置の実現

人見啓太朗

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(A)

Institution: 東北大学

2025/04/01 - 2029/03/31
TlBr半導体による高感度・高精細フォトンイメージングの実現

小野寺敏幸, 野上光博, 豊川秀訓, 人見啓太朗

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(A)

Institution: 東北工業大学

2024/04/01 - 2029/03/31
陽子線治療効果を増強する新規DDS技術の開発

寺川貴樹, 野上光博, 人見啓太朗

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(B)

Institution: 東北大学

2024/04/01 - 2027/03/31
放射線の三次元影と人工知能が拓く放射線イメージングの新機軸

北山佳治, 野上光博, 人見啓太朗

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(C)

Institution: 国立研究開発法人日本原子力研究開発機構

2023/04 - 2026/03
Innovative study on carrier transport mechanism in TlBr gamma-ray detector based on wavelength-resolving neutron imaging

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Kyushu University

2022/04/01 - 2025/03/31
TlBr半導体の純化過程における不純物挙動と電荷輸送特性の評価

野上光博, 平田岳史, 渡辺賢一, 人見啓太朗

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(B)

Institution: 東北大学

2022/04/01 - 2025/03/31

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当該年度の研究実績の概要は以下の通りである。 1)TlBr原料の純化を帯域精製法を用いて行った。純化したTlBr結晶を用いて帯溶融法により結晶育成を行った。育成したTlBr結晶を前方部・中間部・後方部に切りわけ、それぞれの結晶用いて各部位で４個ずつTlBr検出器の製作を行った。また、TlBr結晶およびTlBr検出器をそれぞれ不純物分析、電荷輸送特性評価試験に提供した。 2)項目1)で準備した前方部・中間部・後方部のTlBr結晶(TlBr検出器製作に用いた近傍の結晶)に対して、LA-ICP-MSによる不純物元素分析を行った。レーザーの照射条件は昨年度と同様に照射視野200 um × 200 um、レーザー出力10 mWで分析を行った。元素スクリーニング分析の結果、分析対象元素を約20元素まで絞り込みTlBr結晶中の含有量の分析を行った。また、試料の深さ方向の分析を行い、表面汚染の影響評価を行った。分析の結果帯域精製により、後方部に著しく集積する元素、反対に全ての部位に万遍なく分布する元素があることが分かった。 3)項目1)で育成したTlBr結晶の前方部・中間部・後方部のそれぞれの部位から製作したTlBr検出器の特性評価および電荷輸送特性の評価を行った。特性評価では、137Cs密封線源を用いてエネルギー分解能の評価を行った。また、電荷輸送特性の評価では、241Am密封線源を用いて電子の移動度μとキャリア寿命τの積であるμτ積の評価を行った。その結果、前方部の結晶から製作したTlBr検出器が最も優れた特性をもつことが分かった。 4)TlBr結晶中に含まれる不純物濃度とTlBr検出器の電荷輸送特性の相関関係に関する検討を行うために、LA-ICP-MSによる不純物分析結果の整理、TlBr検出器の諸特性の整理、および文献調査を行った。
TlBr半導体の純化過程における不純物挙動と電荷輸送特性の評価

野上光博, 人見啓太朗, 渡辺賢一, 平田岳史

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(B)

Institution: 東北大学

2022/04 - 2025/03
Innovative study on carrier transport mechanism in TlBr gamma-ray detector based on wavelength-resolving neutron imaging

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Kyushu University

2022/04 - 2025/03
TlBr中の電荷捕獲準位解明と全吸収γ線エネルギースペクトロメータ開発への挑戦

金子純一, 人見啓太朗

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(C)

Institution: 北海道大学

2021/04 - 2024/03

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TlBrの原材料精製、単結晶育成をすすめた。4Nグレードの原材料を帯域精製中心に純化し、TlBr単結晶を育成した。このTlBr単結晶から検出器を作製し、共同研究先である東北大学と共同して電荷キャリア輸送特性等の評価を進めた。原材料精製、単結晶育成技術に各種改良を重ねた結果、電荷収集効率が大幅に改善した。精製や単結晶育成時の雰囲気に関する改良を段階的に進めると共に、帯域精製に関しては安定して300回の精製を行っている。単結晶育成も同様に信頼性のある炉の開発に成功した。世界的な半導体不足の影響を受け、装置開発が大分遅れたが、年度内に予定していた装置の改良は概ね完了した。 662keVγ線を使用した実験では全吸収ピークがまだ立っていないことから、欠陥低減に加え、電極作製方法等の改善を今後進める。特に加工方法に関してはこれまでのアプローチを肯定する成果を得られたものと判断している。また電荷捕獲トラップを検証するための光照射I-V測定装置の開発も概ね予定通り進んでいる。直径0.5"のTlBr単結晶が安定して合成可能となったことから、今後の各種実験の進展も期待できる。 <BR> 今後は5Nグレードの原材料の使用なども予定しており、従来行ってきた欠陥低減や電極に関する実験を積極的に進め、実用的なTlBr半導体検出器の実現を目指す。さらに安定して測定が可能となったカソードルミネッセンス法に加え、光I-V測定により捕獲準位の定量的な研究に切り込んでいく。
連携計測による線源探査ロボットシステムの開発研究

人見啓太朗, 野上光博, 高田英治, 金子慎一郎, 田村雄介, 北山佳治, 鳥居建男

Offer Organization: 文部科学省

System: 国家課題対応型研究開発推進事業（英知を結集した原子力科学技術・人材育成推進事業）

Institution: 東北大学

2021 - 2024/03
超高ピーク対バックグラウンド比を有するBNCT用治療線量モニターの開発

人見啓太朗, 野上光博, 小野寺敏幸, 渡辺賢一, 田中浩基, 石井慶造

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(A)

Institution: 東北大学

2020/04 - 2024/03

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本研究はガンマ線ピーク効率が非常に高い臭化タリウム(TlBr)化合物半導体を用いて、高エネルギー分解能を有するガンマ線検出器を開発し、高ピーク対バックグラウンド比でホウ素が中性子と反応する際に放出される478 keVの即発ガンマ線を検出することが可能なBNCT用治療線量モニターを実現することを目的としている。今年度はRFスパッタ法を用いた電極形成および加速器中性子源を用いた即発ガンマ線の検出に関する研究を中心に行った。 TlBr検出器の電極はこれまで真空蒸着法を用いて形成されてきた。本研究では良好な電極が形成できると期待されるRFスパッタ法を用いて検出器の電極形成を試みた。育成したTlBr結晶を切り出し表面加工を施して検出器製作に用いる基板とした。TlBr検出器の電極材料としてはTlが良好であるが、Tlスパッタリングターゲットは入手困難である。このため、スパッタリングターゲット製作方法の検討を行った。検討の結果、Tlを真空蒸着したターゲットを製作した。製作したTlターゲットを用いることによりTlBr結晶上にRFスパッタ法によりTl電極を形成する事に成功した。また、本研究ではTlBr検出器を用いて加速器中性子源からの中性子照射による478 keV即発ガンマ線の測定を行った。青森県量子科学センターのNRTラインにおいて即発ガンマ線計測実験を行った。ホウ素入りポリエチレンをターゲットとして中性子照射を行った。この時、ホウ素が中性子と反応する際に放出される即発ガンマ線の検出をTlBr検出器を用いて行った。高エネルギーガンマ線によるバックグラウンドや511 keVのガンマ線が混在する測定環境においてTlBr検出器を用いて478 keVの即発ガンマ線を明確に検出することに成功した。
Development of a simple high sensitivity 90Sr detector based on the simultaneous measurement with tandem type of proportional counters under high radiation background

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2019/04 - 2024/03
半導体SPECTの急速的普及を果たすTlBrガンマ線イメージングアレイの開発

小野寺敏幸, 人見啓太朗

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(B)

Institution: 東北工業大学

2020/04 - 2023/03

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2021年度は、プレス成型で得られるＴｌＢｒ結晶（20ｍｍｘ20ｍｍ）の更なる高品質化と結晶性およびデバイス評価について並行して進めてきた。高品質化では、試料取り出し時に生じるＴｌＢｒが接するパンチプレートとの固着によるクラックを防ぐため、新たに特殊表面処理を施したパンチプレートを採用し課題解決した。また、2020年度まではプレス原料に試薬レベルのＴｌＢｒ粉末を使用してきたが、2021年度は帯域精製法を用いて独自に高純度化したＴｌＢｒを使用した。プレス成型したＴｌＢｒ結晶の結晶性の評価では、従来までＸ線回折を用いてきたが、試料の面内方位分布を詳細にみいだすため、電子後方散乱回折（ＥＢＳＤ）を用いた評価法を追加した。その結果、従来まで単結晶と推測していた試料面は僅かに異なる複数の方位から構成されており、改善の余地がみられた。得られた試料をもとに金電極を持つ単画素のガンマ線検出器を製作し、１３７Ｃｓからのガンマ線を照射し、ガンマ線応答スペクトルを取得した。その結果、未精製原料と比較すると独自精製したＴｌＢｒを用いた方がＴｌＢｒ検出器からの出力が改善したが、一般的な結晶成長法である融液成長で育成したＴｌＢｒ結晶と比較すると十分とは言えなかった。しかしながら、ＴｌＢｒ検出器からはガンマ線照射にともなう明確なパルスが得られており、現状の特性であってもイメージング検出器として動作する可能性がある。
Development of a portable high-resolution gamma-ray spectrometer for nuclear facilities

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Japan Atomic Energy Agency

2020/04 - 2023/03
Study of photon detection for time-of-flight PET

Nishikido Fumihiko

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Research (Exploratory)

Institution: National Institutes for Quantum Science and Technology

2019/06 - 2022/03

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Recently , mainstream of PET scanner development is time-of-flight PET which requires high coincidence timing resolution. In this study, we investigated the improvement of the timing resolution of a semiconductor (thallium bromide)-based PET detector in order to realize performance PET detectors beyond the scintillation detectors typically used in PET detectors. In our experiments, we succeeded to obtain timing resolutions of several hundred picoseconds by using Cherenkov emission. In addition, the experimental result indicate that higher timing resolution could be achieved by increasing detected photons of Cherenkov radiation.
形状がフレキシブルな有機半導体放射線検出器の高度化と新しい放射線量計測手法の開発

高田英治, 錦戸文彦, 人見啓太朗, 高橋浩之, 岡田裕之, 飯本武志

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(B)

Institution: 富山高等専門学校

2018/04 - 2022/03

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申請者らは、放射線計測用蛍光体（シンチレータ）の発光を有機半導体光出器（有機PD）で測定する新型放射線計測手法について研究し、放射線計測への適用可能性を示してきた。有機PDの形状の可変性を生かすことで、今までにない軽量小型で、かつ動的使用に適す放射線検出器が実現可能であると考えている。昨年度の研究により、インクジェット法によって銀インクを塗布することで、有機半導体放射線検出器として動作させることが可能であることが示した。しかし、今年度、絞り込んだX線を素子に照射して、照射位置と電流発生量を調べたところ、電極の金属にX線を照射した場合に大きい電流が発生しているという結果が得られた。すなわち、金属を含有する電極材料を用いることは「生体等価」という長所を損なうものであることが分かった。そこで、今後は可能な限り、薄膜金属とカーボンペーストを電極として使用することとした。パルス計測化については、ノイズ成分による暗電流等の理由により、測定できていない。今後、ガードリングの採用や材料の再探索等により、パルス計測化の実現を目指す。高速中性子を対象とする測定についても、まずシンチレータを併用する間接測定から検討を行う。本検出器の用いる線量計測概念構築のため、ブロック状のシンチレータの表面及び内部に素子を設置し、電流計測を行った。シミュレーションによる電流発生量推定値と比較したところ、同様の傾向が示されたが、シンチレータ内でのシンチレーション光の反射等の考慮が不十分だったため、ややずれた値となった。シンチレーション光の伝搬についてもシミュレーションにおいて考慮することとし、医療用に適した体系で実験を行う予定である。
Realization of Cherenkov PET with photon-electron hybrid detectors using transparent semiconductors

Hitomi Keitaro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Research (Exploratory)

Institution: Tohoku University

2019/06 - 2021/03

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Thallium bromo-chloride (TlBrCl) is a transparent semiconductor. TlBrCl crystals were grown by the traveling molten zone method using zone-purified materials in this study. Semiconductor detectors were fabricated from the TlBrCl crystals by evaporating electrodes on the crystals. A TlBr0.7Cl0.3 semiconductor detector exhibited an energy resolution of 6.4% full width at half maximum for 511-keV gamma rays at room temperature. A silicon photomultiplier (SiPM) was coupled optically to a TlBr0.3Cl0.7 semiconductor detector. The TlBr0.3Cl0.7 detector was irradiated with a 22Na gamma-ray source at room temperature. The gamma ray interacting with the detector material creates electron-hole pairs and Cherenkov photons simultaneously in the crystal. Simultaneous detection of the charge signal and the photon signal was achieved with the device in this study. The TlBrCl detectors are attractive for applications in positron emission tomography.
Development of a Compton camera using a single scattering-absorption detector fabricated from an ultrasensitive thallium bromide semiconductor

Hitomi Keitaro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2015/04 - 2020/03

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A Compton gamma-ray imaging camera was developed using an ultrasensitive compound semiconductor, thallium bromide (TlBr). Gamma-ray detectors were fabricated from TlBr crystals grown from purified materials in this study. Images of gamma-rays of 662 keV from a 137Cs source and gamma-rays of 1173 keV and 1333 keV from a 60Co source were successfully obtained from a pixelated TlBr detector with a Compton imaging method. Because TlBr detectors exhibit high stopping power for high-energy gamma rays, the developed detectors are promising for applications in nuclear medicine for imaging of gamma rays from multiple elements, proton therapy for estimation of dose distributions, and gamma-ray imaging spectroscopies.
Fundamental study for development of a large field of view general-purpose SPECT using a new semiconductor detector

Nagano Nobumichi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (C)

Institution: Tohoku University

2016/04 - 2019/03

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A fundamental study was performed for developing large field of view general-purpose SPECT systems using a TlBr semiconductor detector. TlBr is a compound semiconductor suitable for fabricating low-cost and high-performance detectors. A large-area pixelated TlBr detector was fabricated in this study. The detector had the area of 14 mm x 14 mm on which 4 x 4 pixel electrodes (pixel size of 2 mm x 2 mm) were constructed. The thickness of the detector was 3 mm. The detector successfully detected gamma-rays from a 137Cs radiation source.
Study of energy analytic type gamma-ray dose rate meter for appropriate nuclear reactor decommissioning process

Onodera Toshiyuki, Hitomi Keitaro, Orihara Hikonojo

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Young Scientists (B)

Institution: Tohoku Institute of Technology

2014/04 - 2017/03

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Constructing reactor decommissioning technique is indispensable matter associated with Japan’s energy policy. Safety precaution for environment and worker should be ensured by monitoring radiation dose in the nuclear plant. In this study, a semiconductor gamma-ray dose rate meter with energy analytic type has been developed using thallium bromide (TlBr) semiconductor crystals characterized with high gamma-ray interaction efficiency. Semiconductor production process for TlBr crystal with suitable detector performance was constructed by considering material purification method and crystal growth method. TlBr gamma-ray detectors fabricated from grown in this study was successfully realized high energy resolution for gamma-rays from a 137Cs radioactive source.
Development of new X-ray direct conversion films for high-sensitive flat-panel detectors

HITOMI Keitaro, KIM Seong-Yun, ONODERA Toshiyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2014/04 - 2016/03

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Development of X-ray detectors using a compound semiconductor, thallium bromide (TlBr), was performed for realizing high-sensitive flat-panel detectors. High-pure TlBr was obtained by the horizontal zone purification method. Small pixel electrodes were formed successfully on TlBr single crystals. Thin-film detectors were fabricated from TlBr thin films deposited on ITO glass substrates by the vacuum evaporation method. The fabricated thin films exhibited high resistivity at room temperature.
Development of an RI imaging method for observing the dynamic of X ray tracer in an intracellular by the resolution of a micron

ISHII Keizo, TERAKAWA Atsuki, MATSUYAMA Shigeo, HITOMI Keitaro, MORI Satoshi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2011/04 - 2015/03

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Metallic elements such as iron and zinc play an important role in the growth and life activity of plants. It is expected that the in-vivo observation of these metallic elements in plants enables to elucidate their metabolism mechanism at a molecular level and it becomes useful for the selective breeding and the artificial cultivation. We developed a 3D RI imaging system based on the use of RI source emitting only x-rays (X-ray RI source) and the principle of a pinhole camera. We succeeded to perform 3D RI imaging by using a 55Fe source as the X-ray RI source. We applied it to investigate the movement of 55Fe tracer in a sprout of Japanese mustard spinach. We obtained the time change of distribution of 55Fe tracer in the plant and found that the 55Fe accumulation in leaf became remarkable after a period of time after administration of 55Fe.
Development of thallium bromide semiconductor detectors for whole-body PET scanners

HITOMI KEITARO

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2010/04 - 2015/03

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Thallium bromide (TlBr) semiconductor detectors were developed for whole-body positron emission tomography (PET) scanners. Large volume TlBr crystals were grown successfully and technologies for stable fabrication of 5 mm × 5 mm × 5 mm TlBr detectors were established in this study. The developed TlBr detector exhibited a timing resolution of 6.5 ns. The TlBr detectors operated stably for 48 hours at room temperature and the result indicates that the TlBr detectors have sufficient stability as gamma-ray detectors for PET scanners. The TlBr detector exhibited the best energy resolution of 1.1% FWHM for 662-keV gamma rays at room temperature. The TlBr detectors developed in this study are very promising not only for PET applications but also for other advanced gamma-ray applications.
Development of next-generation PET modules using 3D TlBr detectors

HITOMI Keitaro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Young Scientists (B)

Institution: Tohoku Institute of Technology

2008 - 2009

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Semiconductor gamma-ray sensors using a compound semiconductor, thallium bromide (T1Br), were developed for the next-generation PET scanner with ultra-high spatial resolutions. Crystal growth and fabrication and evaluation of TlBr gamma-ray sensors were performed in this study. It can be concluded that the TlBr sensor is a practical candidate for gamma-ray detectors constructing PET scanner since the TlBr detectors exhibited good timing performance with good long-term stability.
三次元位置検出型臭化タリウム放射線検出器の開発

人見啓太朗

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 若手研究(B)

Institution: 東北工業大学

2006 - 2007

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前年度までの研究によって、臭化タリウム検出器の性能が市販されているテルル化カドミウム検出器を大幅に凌駕することが実証できた。この前年度の成果を受け、本年度は臭化タリウム検出器の実用化へ向けた取り組みを行った。結晶育成においては、帯域精製法による素材の精製回数を1回、100回、300回としたものを用意し検出器を製作し比較した。その結果、100回程度の帯域精製で実用に十分な性能を持つ臭化タリウム検出器を製作できるとの結果を得た。また、信号処理系統を工夫し、詳細な検出器内のガンマ線の相互作用位置を同定することにより、臭化タリウム検出器から662keVのガンマ線に対して1%の分解能を得ることができた。臭化タリウム検出器の実用化への最大の課題は、その性能が時間の経過とともに劣化するポラリゼーション現象であった。本研究により、臭化タリウム結晶に電極材料としてタリウム金属を応用することにより、検出器のポラリゼーション現象を大幅に抑制することができるという知見を得ることができた。また、本研究では、タリウムは他の金属材料とは異なり、臭化タリウム自身を構成する原子であることから、電極において母材との電気化学反応が起こり、検出器の性能が安定するというモデルの構築も行った。以上、本研究では、結晶の育成、検出器製作・評価、信号処理、長期安定動作といった課題を解決し、三次元位置検出型臭化タリウム検出器を完成することができた。本研究の成果は、放射線の高度利用に貢献するものである。

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