九州大学-研究者情報 [金政浩 (准教授) 総合理工学研究院エネルギー科学部門]

英知を結集した原子力科学技術・人材育成推進事業
2020.04～2023.03, 代表者：篠原宏文, 日本分析センター, 日本原子力研究開発機構廃炉国際共同研究センター
放射性廃棄物および燃料デブリ中分析対象核種78種の分析は、現在化学処理により峻別分離を行った後に、放射能分析を行い、定量しているが、液体シンチレーション検出器によるβ線、X線、α線とGe, NaI検出器等によるγ線の測定スペクトルは核種毎に異なる応答を示し、測定スペクトルはその線形重ね合わせで表せるという第1原理に基づき、これらのスペクトルデータを同時に統一的に解析するスペクトル解読法（Spectral Decryption Method）を開発する。これにより、核種分析能を大幅に改善し、峻別化学分離を不要とすることで、化学処理プロセスを大幅に軽減することを目指す。.

ミュオグラフィー陸から海への展開ー
2021.04～2024.03, 代表者：田中　宏幸, 東京大学地震研究所, 東京大学国際ミュオグラフィ機構（日本）
これまでは陸で活用されてきたミュオグラフィ技術を海へ適用する。ミュオンを検知する検出器を東京アクアラインの海底トンネル部に敷設し、海面の潮位変動や海底岩盤内の天然ガスの探索を行う。九州大学ではトモグラフィを活用した手法で資源探査の部分を担当する。.

ギザの大ピラミッド内部調査
2018.04～2020.03, 代表者：吉村作治, 東日本国際大学, 東日本国際大学
エジプトのギザにある大ピラミッドの内部構造探査を行う。.

半導体デバイスのミューオン誘起ソフトエラー率評価のための技術基盤構築
2016.04～2019.03, 代表者：渡辺幸信, 九州大学, 九州大学（日本）
次世代半導体デバイスの信頼性問題の１つとして、宇宙線ミューオン起因ソフトエラーと呼ばれる
一過性の誤動作・故障現象がある。本研究では、最先端ミューオン施設を用いた
正・負ミューオンによるソフトエラー試験用照射技術を開発する。
また、物質内ミューオン輸送や付与電荷のデバイス内輸送計算からなる
統合シミュレーションコードを実用化し、照射データの解析に適用する。
さらに、エラー率シミュレーションの不確定性要因の１つである
低エネルギー宇宙線ミューオンの計測システムを開発し、
建屋内環境下の宇宙線ミューオンの空間分布や入射方向・エネルギー分布を計測する。
最終的に、超低電圧LSI 等の次世代デバイスに対するミューオン起因ソフトエラー評価に
特化した先端基盤技術を構築し、実デバイスの評価に応用する。.

低価格・高速・高精度放射能測定装置の実用化開発
2012.10～2014.09, 代表者：西沢博志, 三菱電機, 独立行政法人科学技術振興機構(日本)
食品中に含まれる放射性物質の濃度を測定する装置の開発。新しい信号処理技術を用いて、低価格・高速・高精度な検出器を目指す。.

加速器中性子利用99Mo等医学用RI生成開発研究
2011.05～2015.03, 代表者：永井泰樹, 日本原子力研究開発機構, 日本原子力研究開発機構
3大成人病診断に不可欠な99mTcの親核(99Mo)を含む短寿命RIの安定確保は急務であり、これらRIの国内生成の方法を確立する事は国民の健康に関わる重要な課題である。我々が提案した加速器中性子利用によるこれらRI生成法は安定確保・核不拡散に抵触しない、施設が廉価に作れる等の優れた利点を有し世界的に期待されている。国益・世界への貢献両面から、速やかに本研究を遂行し、その方式を実現する。.

研究業績

主要原著論文

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1.	金　政浩, 放射線計測分野への機械学習の応用 ― 核データ測定とガンマ線分析の例 ―, 原子力学会核データ部会「核データニュース」, 125, 5-13, 2020.04, [URL], 機械学習の歴史を概観し、第三次機械学習ブームの終焉は来ない…あるいは当分来ないことを示した。また、放射線計測分野と機械学習の親和性の高さについて紹介し、私が実施した例を2つ示した。中性子スペクトルアンフォールディングの例では、初めて機械学習を触ったとしても、何十年も使われている伝統的なコードと同等の性能を出せることを示せた。また、人力で解析されることが多いガンマ線スペクトルに関しても機械学習で(少なくとも)核種同定をできることを示した。核種同定だけでも応用先はあると考えているが、今後は放射能推定まで拡張し、複数核種が混在する例にもチャレンジしていく予定である。.
2.	Md Kawchar Ahmed Patwary, Tadahiro Kin, Katsumi Aoki, Kosuke Yoshinami, Masaya Yamaguchi, Yukinobu Watanabe, Kazuaki Tsukada, Nozomi Sato, Masato Asai, Tetsuya K. Sato, Yuichi Hatsukawa, Shinsuke Nakayama, Measurement of double-differential thick-target neutron yields of the C(d,n) reaction at 12, 20, and 30 MeV, journal of nuclear science and technology, 10.1080/00223131.2020.1819908, 58, 252-258, 2020.09, [URL], While designing deuteron accelerator neutron sources for radioisotope production, nuclear data for light elements such as Li, Be, and C have been systematically measured in the deuteron energy range from a few MeV to around 50 MeV. Currently, the experimental data available on double-differential thick-target neutron yields (DDTTNYs) are insufficient, especially for deuteron energies between 18 and 33 MeV. In this study, we measured the DDTTNYs of (d,n) reactions on ^natC target for incident deuteron energies of 12, 20, and 30 MeV using the multiple-foil activation method to improve nuclear data insufficiency. The neutrons were detected at emission angles of 0°, 10°, 20°, 30°, and 45°. We applied the GRAVEL code for the unfolding process to derive the DDTTNYs. The results were compared with the calculation by the deuteron-induced reaction analysis code system (DEURACS), and the DEURACS calculation underestimated our results 12 and 20 MeV deuteron. The present data were also used to confirm the systematics of the differential neutron yields at 0° and total neutron yield per incident deuteron in 12–30 MeV of deuteron energy..
3.	小森智博, 金政浩, Kullapha Chaiwongkhot, 永田悠太, 佐藤光流, 渡辺幸信, PHITS と PARMA モデルを用いたミュオグラフィシミュレーションシステムの開発, 応用物理学会放射線分科会誌「放射線」, 45, 1, 48-52, 2019.04, We have developed a simulation system of muography based on PHITS + PARMA model. The simulation system is made for estimation of measurement time and investigation of degradation of infrastructure building. In the present paper, we show the architecture of the simulation system and its feasibility. The simulation system reproduce experimental cosmic-ray muon distribution. Furthermore, appropriate muography image could be calculated for a simple geometry..
4.	Kullapha Chaiwongkhot1, Tadahiro Kin, Ryo Sasaki, Hikaru Sato, Yuta Nagata, Tomohiro Komori, Yukinobu Watanabe, A Feaibility Study of 3D Cosmic-Ray Muon Tomography with a Portable Muography Detector, JPS Conference Proceedings (Proceedings of the Second International Symposium on Radiation Detectors and Their Uses (ISRD2018)) 24, 011010 (2019), https://doi.org/10.7566/JPSCP.24.011010, 24, 011010, 6 pages, 2019.01, The Maximum Likelihood-Expectation Maximization (ML-EM) method was applied to 3D image reconstruction of cosmic-ray muon tomography. The feasibility was examined by using Monte Carlo simulation for a simple configuration where two lead blocks were placed at a different height from a muography detector. The 2D projection of the average thickness of the blocks as a function of the muon direction was simulated for multiple detection positions. The 3D image of the density profile was reconstructed by applying the ML-EM method to the simulated projections. It was found that the image reproduces reasonably well the position of the two blocks. The effect of the limited number of detection positions and the number of iteration in the ML-EM method on the image reconstruction was investigated in detail..
5.	Tadahiro Kin1, Md. Kawchar Ahmed Patwary, Masaki Kamida, Katsumi Aoki, Naoto Araki, Kosuke Yoshinami, Yukinobu Watanabe, Masatoshi Itoh, Development of Radioisotopes Production Method by Accelerator-Based Neutron: Activity at Kyushu University, JPS Conference Proceedings (Proceedings of the Second International Symposium on Radiation Detectors and Their Uses (ISRD2018)) 24, 011010 (2019), https://doi.org/10.7566/JPSCP.24.011031, 24, 011031, 6 pages, 2019.01, We have studied Radioisotopes (RIs) production by the accelerator-based neutron method with neutrons generated via the (d,n) reaction on C or Be in the incident energy range less than 50 MeV. The study has been conducted by the two approaches: proposal of new production routes or new RIs with the accelerator-based neutron method and systematic measurements of double-differential thick-target neutron yields (DDTTNYs). In the study, we have proposed effective production methods of 64Cu for a new PET RI and 92Y for application of radio immunotherapy. Moreover, the DDTTNYs have been systematically measured by the multiple-foil activation method, and a new unfolding code with artificial neural network was developed for the unfolding process. In the present paper, our research activity and results are reviewed comprehensively to show examples of 64Cu production and a TTNY measurement of C(d,n) reaction at 12-MeV deuteron..
6.	金　政浩, 永田悠太, 小森智博, ミュオグラフィによるO&Mのためのインフラ設備内部探査, 物理探査, 71, 169-178, 2018.12, 近年，宇宙線ミュオンの高い透過力を活かして，巨大な対象の内部構造をイメージング（ミュオグラフィ）する技術が活発に開発されてきている。具体的な対象としては，火山やピラミッドなどが挙げられ，前者は噴火機構の解明や防災のため，後者は新たな空洞の探索を通した考古学的研究のために大きな成果を挙げている。我々のグループでは，このミュオグラフィ技術を小・中規模なインフラ設備の内部探査に拡張することを目的として研究を推進している。今回は，我々の開発した検出器の構成と性能を紹介し，それを用いたインフラ設備の測定例を示し，今後の実用化について議論する。.
7.	金政浩, 青木勝海, 三仙幸将, 多重箔放射化法を用いた加速器中性子計測におけるアンフォールディング手法, 応用物理学会放射線分科会会誌「放射線」, 44, 3, 85-91, 2018.11, Recently, development of applications of accelerator-based neutron have been studied. In the development, double differential neutron spectra are necessary for estimation of neutron induced product, shielding design, and so on. However, there is not sufficient experimental data for many reactions. Therefore, the neutron spectra should be systematically measured. The multiple-foil activation method is a powerful technique to measure the spectra. So-called unfolding process is required to derive the spectra in the method. We have compared results by conventional unfolding codes, and also developed a new unfolding code based-on artificial neural network. In the present paper, the characteristics of the unfolding codes are described..
8.	林真照, 東哲史, 西沢博志, 中西正一, 金政浩, 渡辺幸信, アンフォールディング手法を用いたNaI(Tl)シンチレーション式放射能分析装置の開発, 応用物理学会放射線分科会会誌「放射線」, 44, 3, 101-108, 2018.11.
9.	Tadahiro Kin, Yukimasa Sanzen, Masaki Kamida, Yukinobu Watanabe, Masatoshi Itoh, Production of 92Y via the 92Zr(n, p) reaction using the C(d, n) accelerator neutron source, 2016 International Conference on Nuclear Data for Science and Technology, ND 2016 ND 2016 International Conference on Nuclear Data for Science and Technology, 10.1051/epjconf/201714608009, 146, 2017.09, [URL], We have proposed a new method of producing medical radioisotope ⁹²Y as a candidate of alternatives of ¹¹¹In bioscan prior to ⁹⁰Y ibritumomab tiuxetan treatment. The ⁹²Y isotope is produced via the ⁹²Zr (n,p) reaction using accelerator neutrons generated by the interaction of deuteron beams with carbon. A feasibility experiment was performed at Cyclotron and Radioisotope Center, Tohoku University. A carbon thick target was irradiated by 20-MeV deuterons to produce accelerator neutrons. The thick target neutron yield (TTNY) was measured by using the multiple foils activation method. The foils were made of Al, Fe, Co, Ni, Zn, Zr, Nb, and Au. The production amount of ⁹²Y and induced impurities were estimated by simulation with the measured TTNY and the JENDL-4.0 nuclear data..
10.	Tadahiro KIN, Takaya Kawagoe, Shouhei Araki, Yukinobu Watanabe, Production of high-purity medical radio isotope 64Cu with accelerator-based neutrons generated with 9 and 12 MeV deuterons, Journal of Nuclear Science and Technology, http://dx.doi.org/10.1080/00223131.2017.1344585, 54, 10, 1123-1130, 2017.07, [URL], We conducted a feasibility study for producing a high-purity medical radioisotope 64Cu from natural zinc with accelerator-based neutrons. 64Cu isotopes were produced via the 64Zn(n,p) reaction. The accelerator-based neutrons were generated via the C(d,n) reaction using low-energy deuterons of 9 and 12 MeV on a 1-mm-thick carbon target. First, the production purity was estimated using the evaluated nuclear data library JENDL-4.0 and our previously measured thick target neutron yield. We found that even when natural zinc was used as the starting material, significantly high-purity 64Cu could be obtained. Next, irradiation experiments for producing 64Cu using natural zinc were conducted at Kyushu University Tandem Laboratory, with the amounts of 64Cu isotopes and other gamma-emission nuclides measured by a high-purity germanium detector. As a result, high-purity 64Cu isotopes of 1.11(49) × 100 and 3.70 (17) × 100 Bq/g/uC were produced with incident deuteron energies of 9 and 12 MeV, respectively..
11.	Tadahiro KIN, Kullapha Chaiwongkhot, Hiroaki Ohno, Kazuhiro Kondo, Yukinobu Watanabe, Measurement of Zenith and Azimuth Angular Differential Flux of Cosmic-ray Muons Using a Prototype Portable Muography Detector, JPS Conference Proceedings, http://dx.doi.org/10.7566/JPSCP.11.070006, 11, 070006, 6 pages, 2016.11, We have developed a prototype portable muography detector and applied it to measurement of zenith and azimuth angular differential fluxes of cosmic-ray muons on the ground. The detector system was operated stably and the obtained angular fluxes were consistent with the well-known ones. This result demonstrated that the prototype detector has basic performance for muography after careful realignment..
12.	大野裕明, Tadahiro KIN, 鹿嶋亮介, 近藤和博, 渡辺幸信, 可搬性の高い小型ミュオグラフィ検出器の開発研究, 応用物理学会放射線分科会会誌「放射線」, 41, 3, 163-169, 2016.04.
13.	Takaya Kawagoe, Tadahiro KIN, Shouhei Araki, Yukinobu Watanabe, Measurement of neutron yield by multiple-foil activation unfolding method for medical radioisotopes production using accelerator neutrons, the 2014 Symposium on Nuclear Data, http://dx.doi.org/10.11484/jaea-conf-2015-003, JAEA-Conf 2015-003, 297-302, 2016.03, We measured the angle-differential TTNYs of the C(d,n) reaction at Ed = 12 MeV using multiple-foil activation unfolding method. The spectral shape was in good agreement with previous experimental data..
14.	Tadahiro KIN, Yukinobu Watanabe, Development of a Remote and Multipoint Air-dose Rate Monitoring System Using Webcams, 2015 IEEE Nuclear Science Symposium and Medical Imaging Conference, 3 pages, 2015.11, We propose a new webcam-based air-dose rate monitoring system, in which multiple webcams are driven remotely by a single PC..
15.	Tadahiro KIN, Yasuki Nagai, Nobuyuki Iwamoto, Futoshi Minato, Osamu Iwamoto, Yuichi Hatsukawa, Mariko Segawa, Hideo Harada, Chikara Konno, Kentaro Ochiai, Kosuke Takakura, New Production Routes for Medical Isotopes 64Cu and 67Cu Using Accelerator Neutrons, Journal of the Physical Society of Japan, 82, 034201-8 pages, 2013.02, We have measured the activation cross sections producing 64Cu and 67Cu, promising medical radioisotopes for molecular imaging and radioimmunotherapy, by bombarding a natural zinc sample with 14 MeV neutrons. We estimated the production yields of 64Cu and 67Cu by fast neutrons from natC(d,n) with 40MeV 5mA deuterons. We used the present result together with the evaluated cross section of the (n,x) reaction on Zn isotopes. The calculated 64Cu yield is 1.8 TBq (175 g 64Zn) for 12 hours of irradiation; the yields of 67Cu by 67Zn(n,p)67Cu and 68Zn(n,x)67Cu were 249 GBq (184 g 67Zn) and 287 GBq (186 g 68Zn) at the end of 2 days of irradiation, respectively. From the results, we proposed a new route to produce 67Cu with very little radionuclide impurity via the 68Zn(n,x)67Cu reaction, and showed the 64Zn(n,p)64Cu reaction to be a promising route to produce 64Cu. Both 67Cu and 64Cu should be noted to be produced by using fast neutrons..
16.	T. KIN, K. Furutaka, S. Goko, H. Harada, J. Hori, M. Igashira, T. Kamiyama, T. Katabuchi, A. Kimura, K. Kino, F. Kitatani, Y. Kiyanagi, M. Koizumi, M. Mizumoto, S. Nakamura, M. Ohta, M. Oshima, and Y. Toh, THE “4π GERMANIUM SPECTROMETER” FOR MEASUREMENTS OF NEUTRON CAPTURE CROSS SECTIONS BY THE TIME-OF-FLIGHT METHOD AT THE J-PARC/MLF/NNRI, Journal of the Korean Physical Society, 59, 1769, 2011.08.
17.	Tadahiro Kin, Masumi Oshima, Kazuyoshi Furutaka, Mitsuo Koizumi, Yosuke Toh, Atsushi Kimura, Identification of Nuclear Levels of 34S for Determination of the Neutron Capture Cross Section, Capture Gamma-Ray Spectroscopy and Related Topics, AIP Conference Proceedings 1090, 575, 2009.01.
18.	Tadahiro Kin, Ken-ichi Makino, Nobuo Noda, Kazuharu Koide and Masahiro Nakano, The Molecular Dynamics Calculation of Clathrate Hydrate Structure Stability for Innovative Organ Preservation Method, International Journal of Innovative Computing, Information and Control, 4, 2, 249, 2008.02.
19.	Tadahiro Kin, Masumi Oshima, Kazuyoshi Furutaka, Mitsuo Koizumi, Yosuke Toh and Atsushi Kimura, Development of a Spectrometer for Multiple Prompt Gamma-Ray Measurement to Identify Nuclear Levels, FRONTIERS IN NUCLEAR STRUCTURE, ASTROPHYSICS, AND REACTIONS “FINUSTAR 2”, AIP CONFERENCE PROCEEDINGS 1012, 374, 2008.01.
20.	Tadahiro KIN, Ken-ichi MAKINO, Kazuharu KOIDE, Tetsuya NEMOTO, Molecular Dynamics Simulation of Complex Phase Transition of Clathrate Hydrates in Living Body, 2006 International Conference on Innovative Computing, Information and Control, 556, 2007.01.
21.	Tadahiro Kin, Fuminobu Saiho, Sin-ya Hohara, Katsuhiko Ikeda, Kiyohisa Ichikawa, Yusuke Yamashita, Minoru Imamura, Genichiro Wakabayashi, Nobuo Ikeda, Yusuke Uozumi, Masaru Matoba, Norihiko Koori, Proton Production Cross Sections for Reactions Induced by 300 and 392 MeV Protons, International Conference on Nuclear Data for Science & Technology ND2004, 769, Part One, 207-210, 2005.08.
22.	Tadahiro Kin, Fuminobu Saiho, Shinya Hohara, Katsuhiko Ikeda, Kiyohisa Ichikawa, Yusuke Yamashita, Minoru Imamura, Genichiro Wakabayashi, Nobuo Ikeda, Yusuke Uozumi, Masaru Matoba, Masahiro Nakano, Norihiko Koori, Proton production cross sections for reactions by 300- and 392-MeV protons on carbon, aluminum and niobium., Physical Review C, 10.1103/PhysRevC.72.014606, 72, 1, 014606, 2005.07.

主要総説, 論評, 解説, 書評, 報告書等

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金政浩, 永井泰樹, 初川雄一, 原田秀郎, 落合謙太郎, 高倉耕祐, 今野力, 加速器中性子を用いた99mTc等の医療用RI製造研究, 応用物理学会放射線分科会誌「放射線」 vol. 39-2, 59-64 (2013), 2013.08.

金政浩, 地中空洞探査に向けたミュオグラフィ検出器の開発, 日本原子力学会誌, 2016.09, 宇宙から飛来する素粒子「宇宙線ミュオン」を用いた大型構造物の透視が様々な対象に応用され始めている。この技術は、火山学、地質学、考古学などと融合し、学際的な発展を見せている。本誌2015年5月号の解説シリーズでも紹介があったように、その対象は地盤や大型構造物内部の可視化に広がっている。本稿では、私たちの開発している地中空洞探査を目的とした検出器の開発に焦点をあてて紹介する。これまでに作成したプロトタイプ検出器の検出原理や必要な性能を示し、テスト計測の結果から大型構造物内部の密度分布計測の手法を紹介する。.

主要学会発表等

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1.	Tadahiro Kin, Hamid Basiri Eduardo Cortina Gil Andrea Giammanco, , Magnetic Field imaging by Cosmic-ray muon (Magic-µ), IEEE Nuclear Science Symposium and Medical Imaging Conference, 2021.09, Cosmic-ray muon radiography, also called muography, consists of two techniques: absorption and scattering methods. Alvarez proposed the absorption method in 1970 to survey hidden chambers in pyramids. The method has been applied to various targets to inspect their density distribution or inner structure. Since Borozdin invented the scattering method in 2003, the muography approach can also identify nuclides, especially heavy ones such as uranium or plutonium. This study proposes a new approach, which aims at measuring magnetic field. We call the project, Magic-µ, which is short for MAGnetic field Imaging by Cosmic-ray MUons. Charged particles in motion receive Lorentz force when passing through a magnetic field, and they change their trajectories without losing kinetic energy. The charge of the muons, positive or negative, determines in which direction the trajectory is shifted. Given a magnetic flux density and a trajectory length in the magnetic field, i.e., we can uniquely determine the magnetic flux density along the trajectory for a specific trajectory shift. We have proposed a muography system with sensitivity to magnetic fields and developed data analysis methods to estimate a 3-dimensional magnetic flux density. In the present paper, we will treat the outline of the Magic-µ project and prospect..
2.	Hamid BASIRI Tadahiro KIN Eduardo Cortina Gil Andrea Giammanco, Simulation of a first case study for magnetic field imaging with the Magic-μ technique, International Workshop on Cosmic-ray Muography (Muography2021), 2021.11, So far, most of the developments in muography (or cosmic-ray muon radiography) have been based on either the scattering or the absorption of cosmic-ray muons produced by the nuclear interactions between primary cosmic-rays and the nuclei of the Earth’s atmosphere. Applications of muography are increasing in various disciplines. A new use of this technique to measure a magnetic field has recently been proposed by our group. This new application takes advantage of the electric charge of cosmic-ray muons, which causes them to change their trajectory due to the Lorentz force generated by a magnetic field. In this study, we present a feasibility study of the proposed technique by simulating a permanent magnet using the threedimensional finite element solution package AMaze, together with the PHITS Monte Carlo simulation tools. The distribution of magnetic field flux densities around the magnet was calculated in AMaze and entered into the PHITS code. Positive and negative cosmic-ray muons were generated based on the PHITSbased analytical radiation model (PARMA). A comparison of the count rate maps of the detected muons on two position-sensitive scintillator detectors for the magnetic field ON and OFF was studied using PHITS. The simulation results show the effect of the magnet on the count rate maps and are promising for the newly proposed application of cosmic-ray muons, the imaging of a magnetic field..
3.	Tadahiro KIN　　＃Hamid Basiri Andrea Giammanco Eduardo Coritina Gil, 宇宙線ミュオンを用いた磁場イメージング (Magic-µ)　ーシミュレーションによる実現可能性の検討ー, 第69回応用物理学会春季学術講演会, 2022.03, 宇宙線ミュオンを用いたプローブ不要な磁場イメージング手法(Magic-µ)を実施している。本研究では、定性的な磁場のイメージングを行う体系および、2種類の磁束密度を計測可能な体系（透過法および偏向法）を考えている。本発表では、これまでに実施したシミュレーションベースの実現可能性の検討結果について報告する。.
4.	Tadahiro KIN, 日本における放射線計測分野への機械学習の浸透および九州大学における適用例, 第69回応用物理学会春季学術講演会, 2022.03, 機械学習といっても広範にわたるが、そのすべてにおいて前提知識として統計学の知見が必要である。放射線計測分野は統計学の下地があったが、本邦では機械学習モデルの応用は2016−2019年の間ほとんど見られなかった。新型コロナ対策で実験や面会が制限される中、下地があり、なおかつ自宅でもPCひとつで始められる機械学習の応用が2020年より一気にひろがった。まずはその歴史について私の知りうる範囲で述べる。引き続いて、九州大学で私達がこれまでに取り組んできた機械学習モデルの具体例について紹介する。中性子スペクトルアンフォールディング、宇宙線ミュオン・電子識別、ガンマ線スペクトロメトリなどである。.
5.	Tadahiro KIN Hamid BASIRI Eduardo Cortina Gil Andrea Giammanco, Magnetic-field imaging by cosmic-ray muon (Magic-µ), International Workshop on Cosmic-ray Muography (Muography2021), 2021.11, Cosmic-ray muon radiography, also called muography, can exploit the internal structure of an object that muons traversed. In the conventional absorption method, transmission or absorption ratio to background terrestrial muon flux can determine the density length. After the scattering method was invented, muography can inspect nuclear materials' existence in targets. The identification is possible because the nuclear materials have a large electron density to scatter muon at large angles. This study proposes new targets, "magnetic field imaging" and "magnetic flux density measurement." We call the project, Magic-µ, which is short for MAGnetic field Imaging by Cosmic-ray MUons. When a muon traverses in a magnetic field, they are deflected and change their trajectories with its velocity and charge. In other words, the magnetic field must distort the muography image from its original (non-magnetic field condition) image only around the magnetic field. The distortion is detectable with the same process as anomaly detection in the absorption muography. This technique is promising to detect the degradation of a superconductive coil of a fusion reactor because it can find a weak magnetic field region. Next, let us move toward magnetic flux density measurement. In standard muography, muon charge identification is not necessary, but it is mandatory for the magnetic flux density measurement. We will install a muon charge identifier to a standard absorption muography detector. Also, a novel data analysis technique is required to determine the absolute value of the magnetic flux density from the distorted image. We will start with the so-called template matching method, which can find displacement from a template image, a muography image without a magnetic field. We will estimate the magnetic flux density from the displacement. It is useful to understand the magnetic field applied by multipole electromagnets using for Fixed-Field Alternating Gradient accelerator. Additionally to these overviews, simulation results for the feasibility study will be shown in the workshop..
6.	亀井智子川瀬頌一郎佐藤朗田中裕貴中上直人金政浩渡辺幸信, 電荷識別型低エネルギー宇宙線ミュオン計測システムの開発, 第82回応用物理学会秋季学術講演会, 2021.09.
7.	青木勝海金政浩大塚直彦(IAEA) 山口真矢 Mary Alfonse George Mikhail Md Kawchar Ahmed Patwary 渡辺幸信, アンフォールディング法における共分散を考慮した核データ不確かさの伝播解析, 日本原子力学会 2021年春の年会, 2021.03, 代表的な中性子スペクトル測定手法の一つに多重箔放射化法がある。放射化法は積分実験であるため、エネルギー微分中性子収量を導出するためには、いわゆるアンフォールディングによる解析が必要となる。しかしながら、既存のアンフォールディングコード（GRAVELやSAND-IIなど）の多くは実験誤差の伝播すら計算できず、まして核データの不確かさの伝播まで検討した報告はほとんどない。今回我々は、最もよく用いられているGRAVELコードにおける核データの不確かさの伝播を評価する手法を提案する。多重箔放射化法では核データに格納されている中性子励起関数が応答関数となる。今回新たにJENDL-4.0に格納されている励起関数が平均値となるように共分散に基づいてランダムサンプリングしたものを応答関数として用いて中性子収量分布を導出する試行を繰り返し実施した。なお、核種生成量はPHITS（核データJENDL-4.0）を用いて、C(d,n)中性子源による照射（Ed=20MeV、厚い炭素標的）で導出した値を用いた。得られた複数の中性子収量分布を統計解析することで、スペクトルの不確かさを評価することができる。本発表では、開発した手法や導出した不確かさの結果についての詳細を紹介する。.
8.	高橋龍平, 金政浩, 後藤淳, 大島真澄, 機械学習を用いた環境中放射性セシウムの放射能推定, 第68回応用物理学会春季学術講演会, 2021.03.
9.	Tadahiro KIN, Machine learning in radiation metrology:　Neutron spectrum unfolding and Gamma-ray spectrometry , Consultancy Meeting on Machine Learning for Nuclear Data, 2020.12.
10.	金　政浩, Development of Radioisotopes Production Method by Accelerator-based Neutron -activity at Kyushu- university 2020 - , 核データ研究会, 2020.11, Radioisotopes (RIs) production using deuteron accelerator-based neutrons has been studying at Kyushu University. We primarily focus on neutrons generated via the C or Be(d, n) reactions in a target whose thickness is thicker than the deuteron range. These reactions are selected because (1) high intense neutrons having high kinetic energy can generate by the elastic and non-elastic breakup reaction of deuterons, and (2) neutron energy spectrum has a maximum of around a half incident deuteron energy, i.e., varying deuteron energy guides the spectrum shape adjustment. The two approaches have conducted the study: proposal of new production routes and new RIs with the accelerator-based neutron method and systematic measurements of double-differential thick-target neutron yields (DDTTNYs) up to 40 MeV. The present paper shows some examples of past works (92Y production for biodistribution assessment and 132Cs production for alternative environment tracer as 137Cs), and current status (systematic DDTTNY measurement results) of our project..
11.	金　政浩, 医療用などの放射性同位元素の応用とその製造方法〜既存核種の安定供給・新規RIの提案にむけて〜, 2020年量子医療研究会, 2020.01, 当研究室で取り組んでいる、加速器中性子源をもちいた放射性医療同位元素の製造に関する研究を紹介し、既存の核種の安定供給だけでなく、まったく新たなものを製造できる技術であることを紹介した。.
12.	Hikaru Sato, Tadahiro Kin, Yukinobu Watanabe, Double-differential Energy Spectrum of Terrestrial Cosmic-ray Muons in the 100-340 MeV Range, 2019 IEEE Nuclear Science Symposium (NSS) and Medical Imaging Conference (MIC), 2019.10, We have developed a muon spectrometer named full absorption muon energy spectrometer (FAMES) that consists of plastic scintillators to measure cosmic-ray muon energy spectra in the low energy region from 100 to 340 MeV. The detection acceptance of zenith angle can be arbitrarily adjusted in the measurement of double-differential spectra. We measured the double-differential spectra at Chikushi Campus of Kyushu University in Japan by using FAMES. The measured spectra are in good agreement with the calculated ones with the PHITS-based analytical radiation model in the atmosphere (PARMA). From this result, we concluded that PARMA has a predictive power in the low energy range..
13.	Tadahiro Kin, Jun Goto, Masumi Oshima, Machine Learning Approach for Gamma-ray Spectra Identification for Radioactivity Analysis, 2019 IEEE Nuclear Science Symposium (NSS) and Medical Imaging Conference (MIC), 2019.10, Gamma-ray spectrometry for radioactive analysis plays important role on environmental recovery after the Fukushima Daiichi Nuclear Power Plant Accident. A huge amount of debris should be analyzed to determine whether it has potential of secondary pollution or not. In the gamma-ray spectrometry, a screening process is required to determine measurement time to satisfy a prescribed accuracy. In the screening process, short time measurement of gamma-ray spectrum is conducted to estimate the measurement time. In the conventional radioactive analysis procedure, only photo peaks are counted and identified by human. If Compton component in the spectrum can be used, required time of the screening process will be around 10 times shorter than the conventional procedure. That is because total gamma-ray efficiency is around 10 times higher than photo-peak efficiency. We focus on machine learning to take the Compton component into the screening process for efficient measurement cycle without human. For the first step, we have developed a gamma-ray spectrum identification model using the machine learning in the present study. Architecture of the machine learning model is as follows: 1) Input layer having 4096 units is corresponding to a 4k-ch gamma-ray spectrum. 2) The model has two hidden layers having 170 and 40 units, respectively. 3) Output layer has 7 units corresponding to radioactive nuclides interested in the analysis. 4) Activation functions of all units in the hidden layers are ReLU. Softmax function is used for output layer. 5) Backpropagation method with the stochastic gradient descent method is adopted for learning process. A loss function used in the model is the categorical cross entropy. 6) A metrics to evaluate the model is accuracy which is the mean accuracy rate across all predictions for learning dataset. The accuracy for all learning dataset was more than 95% at 20 epochs. We concluded that the model can sufficiently predict a nuclide included in a spectrum..
14.	金　政浩, 放射線計測分野への機械学習の応用 ―核データ測定とガンマ線分析の例―, 日本原子力学会 2019年秋の大会, 2019.09, 現在の第3次機械学習ブームは、機械学習最大の関門であった勾配消失問題と過学習問題のほぼすべてをHintonらが解決したことから始まった。ブーム到来によって、使いやすいライブラリが整備され、あらゆる分野で容易に機械学習を適用できるようになり、放射線計測分野にもその波は押し寄せてきている。本発表では、九州大学が取り組んでいる放射線計測分野への適用例を2つ示した。.
15.	Naoya OKAMOTO, Tadahiro KIN, Yuta NAGATA, Hikaru SATO, Tomohiro KOMORI, Yu HORAI, Infrastructure Survey by Muography, Muographers 2019, 2019.09.
16.	Tadahiro KIN, Rock-filled Dam Muography, Muographers 2019, 2019.09.
17.	Tadahiro Kin, Naoto Araki, Md Kawchar Ahmed Patwary, Katsumi Aoki, Kosuke Yoshinami, Masaya Yamaguchi, Masatoshi Itoh, Yukinobu Watanabe, Production Method of Environmental Tracer Cs-132 by Accelerator-based Neutron, International Conference on Nuclear Data for Science and Technology 2019, 2019.05, Cesium-137 has been well-known as the most problematic nuclide in a nuclear accident. For instance, in the Fukushima Daiichi nuclear power accident, large amounts of radioactive nuclides were released into the environment. There are three dominant nuclides; 137Cs, 134Cs, and 131I. Among all, 137Cs is the dominant radiation source of the environment in these days because of its long half-life (T1/2 = 30 y). Huge effort has devoted to the study on the dynamics of cesium in soil to develop decontamination method or investigate pollution of agricultural crops and so on. In these study, short-time dynamics of cesium in soil is very important. Nevertheless, long half-life radioactive cesium; 137Cs has been using, because no short half-life radioactive cesium is available. Moreover, using unsealed 137Cs source requires careful management to avoid environmental pollution for long time. Although such difficulties are existing, it is clear that further study on cesium dynamics in the environment is important. To enhance these study, we have proposed a new environmental tracer, 132Cs. The dynamics in the environment is completely same as 137Cs, and the gamma-ray energy of 137Cs (662 keV) and 132Cs (668 keV) is very close. Cesium-132 can be produced via the 133Cs(n,2n) reaction by accelerator-based neutron. We have conducted a production experiment of the accelerator-based production method at CYRIC, Tohoku University, Japan. The accelerator-based neutron was generated by the C(d,n) reaction in thick carbon neutron converter by 30-MeV deuteron. A raw material made of Cs2CO3 was irradiated by the neutron and produced radioactivity of 132Cs was measured by a HP Ge detector. Then, to demonstrate its feasibility, the simple dynamics in a few spices of soil was investigated by using a NaI(Tl) detector. We found that sufficient radioactivity of 132Cs can be produced by a few uA of deuteron beam, and the dynamics can be clearly measured..
18.	金政浩, 後藤淳, 大島真澄, 人工知能によるガンマ線分析のためのスペクトル認識, 第66回応用物理学会春季学術講演会, 2019.03, ニューラルネットワークを用いた機械学習モデルで、低統計なガンマ線スペクトルに含まれるガンマ線放出核の種類を識別することに成功した。.
19.	荒木直人、金政浩、上田真輝、青木勝海、渡辺幸信、伊藤正俊, 小・中規模インフラ設備の透視診断に向けたエネルギーウインドウ型ミュオグラフィシステムの提案, 第65回応用物理学会春季学術講演会, 2018.03, これまでは困難だった橋梁や焼却炉などの「小・中規模インフラ設備」の劣化探査への拡張を目的として新たに「エネルギーウインドウ型ミュオグラフィシステム」を提案する。この手法では、数百MeV以下のミュオンを用いる(ウインドウする)ことで、著しく劣化部位のコントラストを上げることが可能となる。.
20.	Tadahiro Kin, Md. Kawchar Ahmed Patwary, Masaki Kamida, Katsumi Aoki, Naoto Araki, Kosuke Yoshinami, Yukinobu Watanabe, Masatoshi Itoh, Development of Radioisotopes Production Method by Accelerator-based Neutron: Activity at Kyushu University, ISRD2018 : International Symposium on Radiation Detectors and Their Uses, 2018.01, Recently, applications of accelerator-based neutron source have been widely expanding in various fields. Among all, we have focused on radioisotopes (RIs) production. The deuteron induced reactions on a thick target made of carbon or beryllium have large advantages to generate high intense neutron [1]. Moreover, since the neutron spectra induced by deuteron have a peak around a half of incident energy, the spectra can be adjusted to reduce amount of by-products, as reported in [2]. For the RI production, deuteron incident energy from 10 to 50 MeV is useful to suppress by-products, because above 50 MeV, too many uncontrollable reactions occur. To estimate quantity and quality of the RI product and to design radiation shielding, double differential thick target neutron yields (DDTTNYs) are required on carbon or beryllium targets for the energy region. However, there is no systematic experimental data available, so far. To overcome the situation, we have systematically measuring DDTTNYs at CYRIC, Tohoku University by means of the multiple-foil activation method. The measurements of the C(d,n) reaction at incident deuteron energies of 12, 16, 20, and 25 MeV and Be(d,n) reaction at those of 16 and 25 MeV were conducted. The DDTTNYs were determined by using unfolding technique from activity of irradiated multiple foils. The analysis method has been also developed by comparison of various conventional unfolding codes as well as an original artificial neural network unfolding code. In addition, production experiment and practical tests were performed for some of feasible RIs such as Cu-64 (a new PET nuclide), Mo-99 (mother of conventional SPECT nuclide Tc-99m), and Cs-132 (a new environmental tracer). We will show details of the analysis method to determine DDTTNYs for the C(d,n) reaction at incident deuteron energies of 12 and 20 MeV. Furthermore as an example of feasibility study, development of chemical process to recover highly enriched Mo-100 target in the Mo-99 production will be given in the presentation. References [1] Y. Nagai, et al., J. Phys. Soc. Jpn., 82 (2013) 1. [2] T. Kin, et al., J. Nucl. Sci. Technol., 54 (2017) 1123..
21.	T. Kin, Y. Sanzen, M. Kamida, K. Aoki, N. Araki, Y. Watanabe, Artificial Neural Network for Unfolding Accelerator-based Neutron Spectrum by Means of Multiple Foil Activation Method, 2017 IEEE Nuclear Science Symposium & Medical Imaging Conference, 2017.10, Recently, applications of accelerator-based neutron are widely spread to many fields. Among all, we have focused on the medical RIs production. In the study, accelerator-based neutrons are generated by 10- to 40-MeV deuteron induced reactions on thick target made of C or Be. For design of irradiation system and estimation of production rate and purity, double differential thick target neutron yields (DDTTNY) are required. There are, however, not sufficient available data. Therefore, in the medical RI production study, the DDTTNY is necessary to be measured. We adopted the multiple foil activation method for the measurement. It is appropriate for the medical RI production study, because the direct activation power of the neutron source can be obtained. The DDTTNY should be derived by an unfolding technique from measured yields of atoms produced via the activation reactions. Performances of conventional unfolding codes are strongly dependent on the initial guess spectrum and a human-inducible parameter of convergence condition. We have developed an unfolding code using artificial neural network (ANN) which requires no initial guess spectrum and no human-inducible convergence condition. Once the ANN is trained, neutron spectrum can be derived from inputting yields of atoms produced via the activation reactions only. To demonstrate the ability to derive the DDTTNY by the ANN unfolding code, we input yields of produced atoms obtained by a multiple foil activation experiment conducted at Kyushu University Tandem Laboratory. The resultant DDTTNY is compared with that by GRAVEL code, which is one of the conventional codes. Since there is no large discrepancy, we found that the ANN unfolding code has same ability to GRAVEL code even without the initial guess spectrum..
22.	Tadahiro Kin, Muography Project at Kyushu University, MUOGRAPHERS 17 General Assembly, 2017.10.
23.	Tadahiro Kin, Muography at Kyushu University, MUOGRAPHERS 16 General Assembly, 2016.11.
24.	Kin Tadahiro, Yukimasa Sanzen, Masaki Kamida, Yukinobu Watanabe, Masatoshi Itoh, Production of 92Y via the 92Zr(n,p) reaction using the C(d,n) accelerator neutron source, International Conference on Nuclear Data for Science and Technology 2016, 2016.09, Medical radioisotopes are widely applied not only for diagnostic but also therapeutic purposes. In particular, radioimmunotherapy (RIT) plays an important role in cancer therapy in recent years. Yttrium-90-ibritumomab tiuxetan is the first RIT agent approved by the U.S. Food and Drug Administration (FDA). After that it has been approved in more than 40 countries. Until Nov. 2011, assessment of biodistribution by using 111In-ibritumomab tiuxetan before administration of 90Y-ibritumomab tiuxetan (called “bioscan”) was required in United States, Japan and Switzerland. The FDA removed the bioscan at Nov. 2011 and the first reason was “analysis of data in 253 patients showed that the In-111 imaging dose and bioscan was not a reliable predictor of altered Y-90 ZEVALIN (the trade name of ibritumomab tiuxetan) bio-distribution”. If ibritumomab tiuxetan is labeled with an Yttrium isotope, it has to be a reliable predictor. Since gamma-ray imaging is used for the bioscan, gamma-ray emitter has to be used as the labelling nuclide. There are a few Yttrium isotopes which emit gamma ray. Among all we focus on 92Y, because it has relatively-long half-life (3.5 h) and decays to a stable isotope (92Zr). We propose a new method to produce 92Y using accelerator neutrons. Yttrium-92 is produced via the (n,p) reaction on 92Zr. A feasibility experiment was performed at Cyclotron and Radioisotope Center in Tohoku University. A carbon thick target was irradiated by 20 MeV deuterons to produce accelerator neutrons. The thick target neutron yield (TTNY) was measured by using the multiple foils activation method. The foils were made of Al, Fe, Co, Ni, Zn, Zr, Nb, and Au. The amount of 92Y production and induced impurities were estimated by simulation with the measured TTNY. The details of the data analysis and the results are shown in the presentation..
25.	Tadahiro KIN, 地中空洞探査に向けたミュオグラフィ検出器開発, 日本原子力学会 2016年春の年会, 2016.03, 宇宙から飛来するミュオンを捉えることで、大型構造物の内部密度構造を透過するミュオグラフィ技術が近年注目を集めている。本報告では、当研究室で開発した地中空洞探査を目的としたミュオグラフィ検出器について、計測原理、構造、テスト計測の結果を発表した。.
26.	Tadahiro KIN, 中村嵩之, 渡辺幸信, 3Dプリンタでのシンチレータの造形を目的としたUV硬化樹脂の開発, 日本原子力学会 2016年春の年会, 2016.03, 3Dプリンタで放射線計測用シンチレータを造形する手法の開発を行った。試作したシンチレータを用いた線源測定の結果、市販のプラスチックシンチレータと比較しても十分な性能があることを確認した。.
27.	Tadahiro KIN, Kullapha Chaiwongkhot, 大野裕明, 近藤和博, 渡辺幸信, Measurement of Zenith and Azimuth Angular Differential Flux of Cosmic-ray Muons Using a Prototype Portable Muography Detector, International Symposium on Radiation Detectors and Their Uses, 2016.01, We have developed a prototype portable muography detector and applied it to measurement of zenith and azimuth angular differential fluxes of cosmic-ray muons on the ground..
28.	Tadahiro KIN, 渡辺幸信, Development of a Remote and Multipoint Air-dose Rate Monitoring System Using Webcams, 2015 IEEE　Nuclear Science Symposium & Medical Imaging Conference, 2015.11, We propose a new webcam-based air-dose rate monitoring system, in which multiple webcams are driven remotely by a single PC..
29.	Tadahiro KIN, 川越敬也, 石井裕也, 渡辺幸信, 重陽子加速器中性子源設計に必要な重陽子核データに関する研究（4）九大タンデム施設における医療用RIの製造テスト実験, 日本原子力学会 2015年春の年会, 2015.03, 九州大学タンデム加速器を用いたC(d,n)反応からの中性子による医療用RI製造実験を行った。さらに箔放射化法を用いた中性子収量分布を求めた。その結果C(d,n)中性子源の利点と64Cu等の将来的な製造量を示せた。.
30.	Tadahiro KIN, 渡辺幸信, Accelerator-based Neutron Source for Medical RI Production, the AFAD 6th Asian Forum for Accelerators and Detectors, 2015.01, Accelerator-based neutron sources have been used for various studies: fundamental physics, engineering application, medical application, and so on. Recently, the applications have been spread to medical RI production. In 2013, a new method for Generation of Radioisotopes (RI) with Accelerator Neutrons by Deuterons (GRAND) has been proposed. In the method for GRAND, two types of neutron sources with deuteron-induced reactions have been considered: one is the DT reaction and the other is the C(d,n) or the Be(d,n) reaction. We focused on the latter reaction. For the reaction, deuterons are accelerated up to a few ~ 40 MeV and bombard on a neutron converter made of thick carbon or beryllium. Thick target neutron yields (TTNYs) of the reactions are very important to predict the amount of medical RIs, however, experimental data are not sufficient. We can simulate TTNYs with calculation codes e.g. PHITS, but the reproducibility is not satisfactory. At the Kyushu University Tandem Accelerator, we have so far measured TTNYs of the X(d,n) reactions systematically (here, X= natC to 181Ta) not only to improve insufficient experimental data but also to modify/develop theoretical models. In addition, we have carried out some test experiments of medical RI production e.g. 58Co and 64Cu for positron emission tomography. At the end of FY2014, however, the accelerator will be shut down, and a new 8 MV Tandem accelerator is now in preparation to star up in FY 2015 at the Center for Accelerator and Beam Applied Science, Kyushu University. Now we have a plan to develop a dedicated beam line as a neutron source to proceed and expand our research work. Our past relevant results and future plan will be reported in the forum. .
31.	川越敬也, Tadahiro KIN, 荒木祥平, 渡辺幸信, Measurement of neutron yield by foils activation unfolding method for medical radioisotopes production using accelerator neutrons, 2014 Symposium on Nuclear Data, 2014.11, Accelerator neutrons have been proposed to produce medical radioisotopes. The C(d,n) reaction is one of the candidates to produce neutrons. The data of thick target neutron yields (TTNYs) is needed for reliable prediction of the amount of production. We measured the angle-differential TTNYs of the C(d,n) reaction at Ed = 12 MeV using multiple-foil activation unfolding method. The spectral shape was in good agreement with previous experimental data. This demonstrates that the experimental method is applicable to prediction of the amount of medical radioisotopes produced with accelerator neutrons..
32.	Tadahiro KIN, 川越敬也, 石井裕也, 荒木祥平, 渡辺幸信, 加速器中性子源を用いた58Ni(n,p)反応による58Coの角度微分収量の計測, 第75回応用物理学会秋季学術講演会, 2014.09, 我々は加速器中性子源による医療用RI製造の研究の一環として、九州大学理学部タンデム加速器にて、C(d,n)中性子源を用いた、PET技術に応用可能な陽電子放出核58Coの生成実験を行った。入射重陽子エネルギーは9MeVで、厚い炭素標的で全エネルギーを吸収させる。生成した中性子は17cm下流のnatNiサンプルに入射する。このサンプルはリボン状(20×300×0.4mmt)であり、炭素標的を中心としてビーム軸から－5～95度の範囲をカバーする様、円弧状に配置した。約7.5時間の照射後、10度毎にサンプルを切り出し、58Ni(n,p)反応で生成した58Co(T1/2=71d)からの崩壊ガンマ線をGe検出器で計測し、その生成量の角度分布を得た。.
33.	Tadahiro KIN, 渡辺幸信, CMOSイメージングセンサを用いた荷電粒子計測の検討, 第61回応用物理学会春季学術講演会, 2014.03, 我々は、手軽に入手可能な「Webカメラ(CMOSイメージングセンサ)」を用いた簡易荷電粒子計測システムの開発を行っている。Webカメラは光検出部にフォトダイオード(PD)を用いている。放射線がPDに入射した際、電離作用によって生じた電荷が、通常の光検出の場合に生じる電子－正孔対と同様の働きをし、「光」の様に観測される。これまでに、本検出器で十分にベータ線を観測できる事がわかっており、放射線教育のための教材として、有用なツールとして用いてきた[1,2]。これまでに作成した計測ソフトでは、Webカメラから得られる画像をリアルタイムに解析して、ほぼデッドタイム無しで、約100cpsでのベータ線カウント数を正確に求める事に成功していた。今回は、さらに「付与エネルギースペクトル」の取得を行う機能を追加した。本検出器ではベータ線は図1の様な「輝点」として観測される。各イベントで得られる輝点の明るさ(画素のRGB値の和)は、放射線がPDに付与したエネルギーと相関がある。今回、90Srベータ線源を用いた測定を行った。その結果、ほとんどのイベントの画素のRGB値は255以下であり、オーバーフローすることは無かった。解析では、各イベントの輝点は複数の画素から成っているため、イベント毎にRGB値の合計値を算出し、その頻度分布(図2)を作成した。Webカメラ用のPDは、ベータ線が透過してしまう厚みであり、なおかつ正確な厚みが公表されていない事も多い。そこで今回は、図2の横軸(RGB合計値)をPDへの付与エネルギーに較正するために、粒子輸送計算コードPHITSによるシミュレーションを活用し、概算で求めた。今回の結果をもとに、WebカメラのようなCMOSイメージングセンサの荷電粒子検出器としての展望についても考察する。 .
34.	Tadahiro KIN, 渡辺幸信, 放射線教育のためのWeb カメラを用いた簡易放射線計測システムの開発；大学および高校教育への実践とその成果, 日本原子力学会2013年秋の大会, 2013.09, 我々の生活に身近な「Webカメラ(CMOSイメージングセンサ)」を用いた簡易放射線計測システムの開発と測定を通して、放射線の「可視化」を主眼とした大学生および高校生への教育を行った。当該教育の具体的な内容および実際に教育を受けた学生、生徒達への教育効果について発表を行う。.
35.	金政浩、川越敬也、渡辺幸信、佐藤望、永井泰樹, 加速器中性子による医療用RI製造における効率的な照射ターゲット体系の設計に関する研究, 原子力学会九州支部第31回研究発表講演会, 2012.12, 加速器中性子による医療用RI製造量の効率化のため、原料サンプルの周りに中性子反射材を置く設計を検討する。今回、64Cuの製造を例として、反射材に炭素板を置いた系の、PHITSによるシミュレーションを行い生成量予測および中性子スペクトル、中性子強度の変化を求めた。.
36.	金政浩, 永井泰樹, 初川雄一, 原田秀郎, 落合謙太郎, 高倉耕祐, 今野力, 加速器中性子を用いた99mTc等の医療用RI製造研究, 第73回応用物理学会学術講演会, 2012.09, 日本では、放射性薬剤のほとんどを海外からの輸入に頼っている。国内のみならず、世界で最も多く使用されている99mTc製剤も例外ではなく、国内生産は全く行われていない。さらに、99mTc製剤に着目すると、約6時間という短い半減期のため、有効期間(いわゆる消費期限)が24－30時間であり、医療施設で薬剤の在庫を置くことができない。また、老朽化した原子炉による生産が大半を占め、計画外に炉が停止して供給が滞ることがたびたび起きている。輸送に関しても、2010年にアイスランド火山の噴火の影響で、放射性医薬品の輸入が完全にストップし、社会的な問題になった。これらの問題を根本的に解決するには、国内での生産が必須である。しかしながら既存の方法を用いて薬剤用に原子炉を新設するのは非現実的であり、核不拡散の観点からも問題がある。そこで、私たちは加速器を用いた中性子源によるRI製造法の開発を進めている。この製造法の一つに、小型の加速器で加速した重陽子をトリチウムターゲットに当てることで発生する14MeV中性子を利用する方法がある。このエネルギーの中性子による、100Mo(n,2n)99Mo反応の断面積は非常に大きいため、99mTcの親核である99Moを効率的に製造することができる。今回の報告では、本手法に関してこれまでに原子力機構核融合中性子源FNS(Fusion Neutronics Source)で行った予備実験の結果、および本手法の特徴について報告を行う。 .
37.	(JAEA) 金政浩、大島真澄、原かおる、木村敦、藤暢輔、小泉光生、原田秀郎, 自動核準位構築法の35Cl(n,γ)反応を用いた有効性の研究, 日本原子力学会2011年秋の大会, 2011.09, 中性子捕獲反応からの多重即発γ線測定のデータを用いた、PCによる自動原子核準位構築法の開発を行っている。本手法の有効性を検討するために、断面積が大きく、過去によく調査のなされている35Cl(n,γ)反応からの多重即発γ線に着目した。JRR-3でのSTELLAを用いた多重即発線測定の結果に本手法を適用した結果について報告した。.
38.	(JAEA) 金政浩, 初川雄一, 永井泰樹, 原田秀郎, 瀬川麻里子, 落合謙太郎, 高倉耕祐, 今野力, 加速器高速中性子源を利用した新しい99mTc 製造サイクルの開発 I, 日本原子力学会2010年秋の大会, 2010.09, 我々は、現在行っている加速器高速中性子源を用いた医療用RI製造法の開発の一環として99mTc国内生産技術の要素開発を行っている。本発表では、天然Mo試料を用いた予備実験の結果と、今後開発する製造サイクルについて製造量の見積もりと混入する不純物の可能性について報告した。.
39.	T. KIN, K. Furutaka, S. Goko, H. Harada, J. Hori, M. Igashira, T. Kamiyama, T. Katabuchi, A. Kimura, K. Kino, F. Kitatani, Y. Kiyanagi, M. Koizumi, M. Mizumoto, S. Nakamura, M. Ohta, M. Oshima, and Y. Toh, THE “4π GERMANIUM SPECTROMETER” FOR MEASUREMENTS OF NEUTRON CAPTURE CROSS SECTIONS BY THE TIME-OF-FLIGHT METHOD AT THE J-PARC/MLF/NNRI, International Conference on Nuclear Data for Science and Technology 2010, 2010.04, A "4π germanium spectrometer" was developed for measurements of neutron capture cross sections of minor actinides and long-lived-fssion products. It was installed on the Beam Line No. 04 of the Materials and Life Science Experimental Facility of the Japan Proton Accelerator Research Complex. The time-of-flight method is used to measure the cross sections. To obtain characteristics of the spectrometer, a measurement was done of prompt gamma rays emitted following neutron capture reactions of gold whose cross section was well studied. In the present paper, we show the procedure of analysis of the data obtained with the spectrometer and discuss the characteristics to measure neutron capture cross section..
40.	T. Kin, K. Furutaka, S. Goko, H. Harada, M. Igashira, T. Kamiyama, T. Katabuchi, A. Kimura, K. Kino, F. Kitatani, Y. Kiyanagi, M. Koizumi, M. Mizumoto, S. Nakamura, M. Ohta, M. Oshima, and Y. Toh, Development of a 4π Germanium Spectrometer for Nuclear Data Measurements at J-PARC, IEEE Nuclear Science Symposium/Medical Imaging Conference, 2009.10, A 4π germanium spectrometer was developed for measurements of neutron capture cross sections of minor actinides and long-lived-fission products. It was installed on the Beam Line No. 04 of the MLF in the J-PARC. We measured its full-energy peak efficiency and gamma-energy resolution at 1.3-MeV with a Co-60 standard source (10kBq). As an example of a result of TOF measurements with the spectrometer, preliminary TOF and energy spectra of Pd-108 are shown in this paper..
41.	Tadahiro Kin, Masumi Oshima, Kazuyoshi Furutaka, Mitsuo Koizumi, Yosuke Toh, Atsushi Kimura, Identification of Nuclear Levels of S-34 for Determination of the Neutron Capture Cross Section, The Thirteenth International Symposium on Capture Gamma-Ray Spectroscopy and Related Topics, 2008.08, We are developing a new method to identify nuclear levels based on neutron capture reactions, named “TELLA-2. Measured data of prompt gamma rays from 33S(n,γ)34S was used to improve the method. We will show how we obtain candidates of nuclear levels..
42.	Tadahiro Kin, Masumi Oshima, Kazuyoshi Furutaka, Mitsuo Koizumi, Yosuke Toh, Atsushi Kimura, Development of a Spectrometer for Multiple Prompt Gamma-Ray Measurement to Identify Nuclear Levels, 2nd International Conference on Frontiers in Nuclear Structure, Astrophysics and Reactions, 2007.09, We developed a spectrometer for multiple prompt gamma-ray measurements to identify nuclear levels to determine neutron capture cross sections. From a test of finding candidates of 15N levels with a developing method, we found performance of the spectrometer is sufficient..
43.	Tadahiro KIN, Masumi OSHIMA, Kazuyoshi FURUTAKA, Atsushi KIMURA, Mitsuo KOIZUMI, and Yosuke TOH, Innovative Method for Nuclear Level Construction Using Measured Multiple Prompt Gamma-rays, INTERNATIONAL NUCLEAR PHYSICS CONFERENCE 2007, 2007.06, MA and LLFP neutron capture cross sections are important for nuclear transmutation. Measurements of prompt gamma are useful method for improvement of accuracy of the data. For the method, ground-state transition gammas have to be known. We developed an innovative method for identification of nuclear levels using measured multiple prompt gamma-ray. For demonstration of the method, we calculated a existing-probability of 15N nuclear levels with measurement of 14N(n,γ)15N reaction with 4π Ge spectrometer at JRR-3. With this demonstration, we verified that the method is useful..
44.	Tadahiro Kin, Fuminobu Saiho, Sin-ya Hohara, Katsuhiko Ikeda, Kiyohisa Ichikawa, Yusuke Yamashita, Minoru Imamura, Genichiro Wakabayashi, Nobuo Ikeda, Yusuke Uozumi, Masaru Matoba, Norihiko Koori, Proton Production Cross Sections for Reactions Induced by 300 and 392 MeV Protons, 2004.10.

特許出願・取得

特許出願件数 7件

特許登録件数 7件

その他の優れた研究業績

2020.01, クフ王のピラミッド（エジプト）の探査に関する研究プロジェクトのうち宇宙線ミュオンを用いた探査を担当。ピラミッドの主構成物である石灰岩の厚みを宇宙から降り注ぐ高エネルギーミュオンで測定可能な装置の開発を行った。.

学会活動

所属学会名

応用物理学会

日本原子力学会

日本核医学会

学協会役員等への就任

2021.04～2023.03, 応用物理学会, 幹事.

2019.04～2021.03, 日本原子力学会, プログラム編成委員.

2017.04～2019.03, 日本原子力学会九州支部, 幹事.

2017.04～2019.03, 応用物理学会, 幹事.

2013.04～2015.03, 応用物理学会, 幹事.

学会大会・会議・シンポジウム等における役割

2021.09.08～2021.09.10, 原子力学会202１年秋の大会, プログラム編成委員.

2021.03.17～2021.03.19, 原子力学会202１年春の年会, プログラム編成委員.

2021.10.16～2021.10.23, IEEE Nuclear Science Symposium / Medical Imaging Conference, Committee.

2020.04～2021.03.01, 応用物理学会放射線分科会次世代放射線シンポジウム 2020, 実行委員.

2020.03.16～2019.03.18, 原子力学会2020年春の年会, プログラム編成委員.

2019.09.11～2019.09.13, 原子力学会2019年秋の大会, 座長.

2019.09.11～2019.09.13, 原子力学会2019年秋の大会, プログラム編成委員.

2019.04～2020.03, 応用物理学会放射線分科会次世代放射線シンポジウム 2019, 実行委員.

2018.09.18～2018.09.21, 第79回応用物理学会秋季学術講演会, 放射線分科会シンポジウム担当幹事.

2016.12.03～2016.12.03, 日本原子力学会九州支部第３５回研究発表講演会, 座長（Chairmanship）.

2016.09.07～2016.09.09, 日本原子力学会 2016年秋の大会, 座長（Chairmanship）.

2016.03.26～2016.03.28, 日本原子力学会 2016年春の年会, 座長（Chairmanship）.

2015.03.20～2015.03.22, 日本原子力学会 2015年春の年会, 座長（Chairmanship）.

2014.03.17～2014.03.20, 2014年第61回応用物理学会春季学術講演会, 座長（Chairmanship）.

2013.09.03～2013.09.05, 原子力学会2013年秋の大会, 座長（Chairmanship）.

2010.09.15～2010.09.17, 2010年原子力学会秋の大会, 座長（Chairmanship）.

2007.09.27～2007.09.29, 2007年原子力学会秋の大会, 座長（Chairmanship）.

学会誌・雑誌・著書の編集への参加状況

2020.07～2021.06, Journal of Nuclear Science and Technology, 国際, 編集委員.

2019.07～2020.06, Journal of Nuclear Science and Technology, 国際, 編集委員.

2017.07～2019.06, Journal of Nuclear Science and Technology, 国際, 編集委員.

学術論文等の審査

年度	外国語雑誌査読論文数	国際会議録査読論文数	合計
2020年度	20		20
2021年度	6		6
2022年度	4		4
2019年度	52		52
2017年度	2	3	5
2016年度	1	1	2
2015年度	1		1
2014年度	1		1
2013年度	2		2

その他の研究活動

海外渡航状況, 海外での教育研究歴

Madrid University, Japan, 2021.02～2021.02.

受賞

第42回環境賞・優秀賞, 日立財団・日刊工業新聞, 2015.06.

第42回環境賞・環境大臣賞, 日立財団・日刊工業新聞, 2015.06.

日本原子力学会技術開発賞, 日本原子力学会, 2011.03.

日本原子力研究開発機構理事長賞, 日本原子力研究開発機構, 2011.10.

JPSJ Papers of Editors' Choice, Journal of the Physical Society of Japan, 2013.05.

ポスター賞, 日本原子力学会核データ部会, 2012.11.

口頭発表奨励賞, 日本原子力学会九州支部, 2012.12.

研究資金

科学研究費補助金の採択状況(文部科学省、日本学術振興会)

2019年度～2021年度, 基盤研究(C), 分担, ホウ素中性子捕捉療法における中性子測定に適した自己放射化有機シンチレータの開発.

2019年度～2021年度, 基盤研究(C), 代表, インフラ設備の迅速探査にむけたエネルギーウインドウ型ミュオグラフィ手法の開発.

2016年度～2018年度, 基盤研究(B), 分担, 本研究では、最先端ミューオン施設を用いた正・負ミューオンによるソフトエラー試験用照射技術を開発する。
また、物質内ミューオン輸送や付与電荷のデバイス内輸送計算からなる統合シミュレーションコードを実用化し、
照射データの解析に適用する。.

2011年度～2014年度, 特別推進研究, 分担, 加速器中性子利用99Mo等医学用RI生成開発研究.

2014年度～2015年度, 挑戦的萌芽研究, 代表, ３Dプリンタを用いたシンチレーション式放射線検出器製造の検討.

2010年度～2012年度, 若手研究(B), 代表, DT反応中性子を使ったTc-99m製剤製造のためのMo-100原料サイクルの開発.

科学研究費補助金の採択状況(文部科学省、日本学術振興会以外)

2018年度～2022年度, Horizon2020 RISE, 分担, INTENSE promotes the collaboration among European, US and Japanese researchers involved in the most important particle physics research projects at the high intensity frontier, and technological spin-offs originating from that research.

Japan played a crucial role in establishing the current picture of the behaviour of elementary particles named neutrinos, most notably with the observation of their oscillations, which in turn firmly proved that neutrinos have a mass. We still don't know the value of their mass, though. What we know is that it must be extremely small, so small to demand explanations from outside of the current Standard Model of particle physics. Neutrino data from the past couple of decades (including some puzzling anomalies) are a crucial input to new theories, which in turn predict new phenomena that are potentially observable by a new generation of experiments in the US with a strong European and Japanese participation.

Funded until 2022, INTENSE will span three complementary directions: new neutrino experiments; a novel search for decays of the muon (another elementary particle, which shares the same properties of the electron apart from a much larger mass) that are suppressed in the Standard Model but are predicted at an observable rate by the same theories that would explain the neutrino oscillations; and finally, multidisciplinary collaboration through “muography”, which uses cosmic-ray muons to image the interior of large targets, including volcanoes, glaciers and archaeological sites. Andrea Giammanco will coordinate the work package devoted to the latter endeavour, which includes particle physicists from the Earthquake Research Institute in Tokyo, Nagoya University, INFN (Italy), Bern University (Switzerland), Wigner RCP (Hungary), UCLouvain and Ghent (Belgium), as well as volcanologists from INGV (Italy) and UCLouvain (Belgium), and two private companies: TECNO IN (Italy) and B12 (Belgium). Other important partners, including CERN, are involved in INTENSE but not in its muography work package..

競争的資金(受託研究を含む)の採択状況

2021年度～2021年度, 高エネルギー素粒子地球物理学公募研究, 代表, 宇宙線トモグラフィのための基礎データ取得.

2020年度～2022年度, 英知を結集した原子力科学技術・人材育成推進事業, 分担, β、γ、Ｘ線同時解析による迅速・高感度　放射性核種分析法の開発.

2020年度～2020年度, 2020年度東京大学地震研究所共同利用, 代表, エネルギーウインドウ型ミュオグラフィの実測を通した原理実証.

2012年度～2014年度, 日本学術振興機構研究成果展開事業先端計測分析技術・機器開発プログラム「放射線計測領域」実用化タイプ, 分担, 低価格・高速・高精度放射能測定装置の実用化開発.

共同研究、受託研究(競争的資金を除く)の受入状況

2019.04～2020.03, 代表, ミューオンによる構造可視化.

2018.04～2019.03, 代表, ミューオンによる構造可視化.

2017.04～2018.03, 代表, ミューオンによる構造可視化.

2016.10～2017.03, 代表, ミューオンによる構造可視化.

2016.04～2017.03, 代表, サイクロトロンを用いた加速器中性子源の研究開発.

学内資金・基金等への採択状況

2017年度～2017年度, QRプロジェクトわかばチャレンジ, 代表, 加速器中性子を用いた学際研究に応用可能な放射性同位元素製造法の検討.

2017年度～2017年度, 九州大学研究活動基礎支援制度国際学会派遣支援, 代表, Artificial Neural Network for Unfolding Accelerator-based Neutron Spectrum by Means of Multiple Foil Activation Method.

2015年度～2015年度, 九州大学基金教職員の海外派遣等支援, 代表, Development of a Remote and Multipoint Air-dose Rate Monitoring System Using Webcams.

九大関連コンテンツ

pure2017年10月2日から、「九州大学研究者情報」を補完するデータベースとして、Elsevier社の「Pure」による研究業績の公開を開始しました。

QIR　九州大学学術情報リポジトリシステム情報科学研究院

総合理工学研究院


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