Search Results 1-20 of 397

  • Development of a Wide Dynamic Range Neutron Flux Measurement Instrument Having Fast Time Response for Fusion Experiments

    ITO Daijiro , MIYAKE Hitoshi , OGAWA Kunihiro , NISHITANI Takeo , ISOBE Mitsutaka , YAZAWA Hiroyuki , TOMITAKA Makoto , KUMAGAI Tsuyoshi , KONO Shigehiro , YAMAUCHI Michinori , MISAWA Tsuyoshi , KOBUCHI Takashi , HAYASHI Hiroshi

    … <p>A wide-range neutron flux measurement instrument is developed herein for monitoring the total neutron emission rate and yield of the Large Helical Device (LHD) during deuterium experiments implemented from March 2017 in the National Institute for Fusion Science (NIFS), Japan. … The instrument is designed for and installed on the Neutron Flux Monitoring (NFM) system, which measures the counting rate using a <sup>235</sup>U Fission Chamber. …

    Plasma and Fusion Research 16(0), 1405018-1405018, 2021


  • Residual stress evaluation by pulsed neutron stress measurement for cruciform welded joints treated with ultrasonic impact method  [in Japanese]

    SUZUKI Tamaki , OKAWA Teppei , HARJO Stefanus , SASAKI Toshihiko

    … <p>The residual stress state inside the cruciform welded joints were measured using the pulsed neutron stress measurement method. … The applied stresses at this time were 75 % or 85 % of the yield point, respectively. …

    Transactions of the JSME (in Japanese) 87(894), 20-00377-20-00377, 2021


  • Monte Carlo sensitivity analysis method for the effective delayed neutron fraction with the differential operator sampling method

    Yamamoto Toshihiro , Sakamoto Hiroki

    … An exact Monte Carlo method for evaluating the sensitivity coefficients of the effective delayed neutron fraction (βeff) with respect to nuclear data is developed using the differential operator sampling (DOS) method. … In particular, the sensitivities of βeff to the yield and spectrum of delayed neutrons, which are dominant contributors to the uncertainty of βeff, can be predicted precisely by the new method. …

    Annals of Nuclear Energy (140), 2020-06-01


  • Mechanism of Improved Ductility of 1500 MPa-class Ultra-high Strength Cold-rolled Steel Sheet Produced by Rolling and Partitioning Method

    Hosoya Yoshihiro , Matsumura Yuta , Tomota Yo , Onuki Yusuke , Harjo Stefanus

    … <p>By using a steel with standardized chemical composition and conventional manufacturing processes for flat-rolled steel strip, a 1500 MPa class stainless steel sheet, whose product of yield strength (YS) and total elongation (El) exceeds 30000 MPa%, was developed and its mass production was established. …

    ISIJ International 60(9), 2097-2106, 2020


  • Anode Shape Dependency of Discharge Characteristics and Neutron Yield of a Linear Type Inertial Electrostatic Confinement Fusion Neutron Source  [in Japanese]

    Itagaki Tomonobu , Hotta Eiki , Hasegawa Jun , Takakura Kei , Tabata Shinnosuke , Matsueda Yasushi

    … <p>A linear inertial electrostatic confinement fusion neutron source equipped with a cooling system for high power operation was developed and its discharge characteristics and neutron production performance were tested under a wide range of discharge conditions. … A maximum neutron production rate of 3.4×10<sup>6</sup> …

    IEEJ Transactions on Fundamentals and Materials 140(9), 464-472, 2020


  • Neutronic Design of Neutron Moderator on a Reentrant-hole Configuration for Kyoto University Accelerator-based Neutron Source (KUANS)  [in Japanese]

    OKITA Shoichiro , TASAKI Seiji , ABE Yutaka

    … The Kyoto University Accelerator-based Neutron Source (KUANS) is a compact neutron source that is mainly used for spectrometer and detector development. … In addition, it is also suited for experiments to study the neutronic design of moderators owing to the relatively low neutron generation yield by <sup>9</sup>Be(p,n). …

    Transactions of the Atomic Energy Society of Japan 19(3), 178-184, 2020


  • Mechanism of Improved Ductility of 1,500 MPa-class Ultra-high Strength Cold-rolled Steel Sheet Produced by Rolling and Partitioning Method  [in Japanese]

    Hosoya Yoshihiro , Matsumura Yuta , Tomota Yo , Onuki Yusuke , Harjo Stefanus

    … using a steel with standardized chemical composition and conventional manufacturing processes for flat-rolled steel strip, a 1,500 MPa class stainless steel sheet whose product of yield strength (YS) and total elongation (El) exceeds 30,000 MPa% was developed and its mass production has been established.Besides the excellent YS-El balance, the developed steel sheet has excellent performance for not only an anti-secondary work embrittlement but also high cycle fatigue endurance.</p><p>Core technology of the developed method is …

    Tetsu-to-Hagane 106(3), 154-164, 2020


  • Feasibility Study of Radioisotope 132^Cs Production Using Accelerator-Based Neutrons

    Md Kawchar Ahmed Patwary , Kin Tadahiro , Araki Naoto , Aoki Katsumi , Yoshinami Kosuke , Yamaguchi Masaya , Watanabe Yukinobu , Itoh Masatoshi

    … We first investigate the production yield and radioactive purity of 132^Cs in a production experiment at the Cyclotron and Radioisotope Center of Tohoku University. … The 132^Cs was produced via the 133^Cs(n,2n) reaction with neutrons generated by bombarding accelerated deuterons onto a 4 mm-thick neutron converter made of carbon. …

    Evergreen 6(4), 280-284, 2019-12

    IR  DOI 

  • Thermal neutron flux evaluation by a single crystal CVD diamond detector in LHD deuterium experiment

    Kobayashi Makoto , Ogawa Kunihiro , Isobe Mitsutaka , Nishitani Takeo , Kamio Shuji , Fujiwara Yutaka , Tsubouchi Tomomi , Yoshihashi Sachiko , Uritani Akira , Sakama Minoru , Osakabe Masaki

    … The single crystal CVD diamond detector (SDD) was installed in the torus hall of the Large Helical Device (LHD) to measure neutrons with high time resolution and neutron energy resolution. …

    Journal of Instrumentation 14(9), C09039, 2019-09-23


  • Thermal neutron distribution in the beam line tunnel of the KEK electron/positron injector linac (The 9th International Symposium on Radiation Safety and Detection Technology (ISORD-9))

    Oyama Takahiro , Iwase Hiroshi , Toyoda Akihiro , Yoshihara Naoto , Sanami Toshiya

    Progress in nuclear science and technology 6, 181-184, 2019-01

  • The formation of fission products from fission fragments with prompt neutron and photon emissions  [in Japanese]

    Okumura Shin

    <p> 核分裂収率は,放射性廃棄物の組成を決定する最も基本的な物理量である。原子炉の臨界性や動特性を支配する即発・遅発中性子放出,あるいは福島の事故誘因となった崩壊熱,宇宙における元素起源の解明,核セキュリティーや核不拡散分野でもその重要性が認識されている。本稿では,核分裂現象の描像を出発点として核データの観点からみた核分裂収率,より精度の高い収率データを提供することを目標とした手法開 …

    Journal of the Atomic Energy Society of Japan 61(11), 775-779, 2019



    Zong Zizhao , Zhao Qiujuan , Zhang Puzhong , Wang Xiaoxia , Xiao Huiwei , Yi Xuan , Mi Aijun , Zhang Liying , Zhu Zhigang

    … The fuel material depletion is correlated to the neutron flux distribution in the reactor, therefore, both the design parameters and the practical operation history are obliged to be considered in the AC and FP yield calculation. …

    The Proceedings of the International Conference on Nuclear Engineering (ICONE) 2019.27(0), 2023, 2019


  • Reduction of the Neutron Induced Noise in the Compact Neutral Particle Analyzer for LHD Deuterium Plasma Experiments

    OZAKI Tetsuo , KAMIO Shuji , NISHITANI Takeo , SAITO Kenji , OGAWA Kunihiro , ISOBE Mitsutaka , OSAKABE Masaki , KOBAYASHI Makoto , the LHD Group

    … However, if the neutron energy is thermalized on the detector, the neutron noise can be estimated only from the total neutron yield, which is monitored by the <sup>235</sup>U fission chamber, etc. … In the experiments, the pure neutron noise on the CNPA has been measured by closing the gate-valve to avoid the charge exchange neutral particle signals. …

    Plasma and Fusion Research 14(0), 3402142-3402142, 2019


  • 7.2.1 Secondary Neutron Production Yields from Thick Targets (TTY)  [in Japanese]

    Nakamura Takashi

    <p>重イオンによる厚い標的からの中性子生成は,加速器施設の遮蔽安全設計において放射線源となる非常に重要なデータである。様々なエネルギーのHeイオンからXeイオンに至るビームをC, Al, Cu, Pbの厚いターゲットに入射して,生成される2次中性子のエネルギースペクトルを,0, 7.5, 15, 30, 60, 90°の角度で,有機液体シンチレータを用いて飛行時間分析法(TOF)によ …

    RADIOISOTOPES 68(8), 543-552, 2019


  • 7.1 Research on Radiation Safety Design for a High-energy Heavy Ion Accelerator—Pre and Post Construction of the HIMAC Facility—  [in Japanese]

    Nakamura Takashi

    <p>HIMAC施設の建設が1984年に決まり,放射線遮蔽安全設計を全面的に依頼された。当時,重イオン輸送計算コードはなく,ともかく安全側の評価をしたが,その時の苦労が,その後の重イオン輸送計算コードPHITSの開発等の研究の発展につながった。HIMAC施設が完成後,それまでほとんどなかった重イオンによる2次粒子,特に安全設計上重要な中性子生成の実験データを系統的に取得した。これらの成 …

    RADIOISOTOPES 68(8), 539-541, 2019


  • Monte-Carlo Simulation of Dissipation Processes in Ion Beam Plasma

    SAKAI Gaku , URANO Takahiro , IWATA Shuya , SEKIGUCHI Kojiro , MATSUMOTO Ryo , TAKAHASHI Toshiki

    … To assess the medical applicability of our neutron source, a combined Monte-Carlo simulation with Diffusion-Reaction model was employed to evaluate the available neutron yield for the Boron Neutron Capture Therapy (BNCT) neutron source under the beam diffusion conditions. … The paper found that the proposed electrostatic trap of deuterium beam ions could provide sufficient neutron generation for the therapy.</p> …

    Plasma and Fusion Research 14(0), 2406009-2406009, 2019


  • DDTTNY Measurement of Accelerator-based Neutron via C(d,n) Reaction by 30-MeV Deuteron by means of Multiple-foil Activation Method

    Patwary Md Kawchar Ahmed , Kin Tadahiro , Aoki Katsumi , Araki Naoto , Yoshinami Kosuke , Watanabe Yukinobu

    … The design of deuteron accelerator neutron source facilities requires reliable yield estimation of neutrons from deuteron-induced reactions. … We have so measured systematically double-differential thick target neutron yields for carbon target using GRAVEL unfolding code. … natC bombarded by deuterons of 30-MeV following the multiple-foil activation method in order to investigate the neutron production yields as high-intensity neutron sources. …

    Proceedings of International Exchange and Innovation Conference on Engineering & Sciences (IEICES) (4), 124-126, 2018-10-18

    IR  DOI 

  • RIKEN Accelerator-driven Compact Neutron Source, RANS (RIKEN Accelerator-driven compact Neutron Source) for Non-Destructive Test of Infrastructures  [in Japanese]

    OTAKE Yoshie

    … A compact neutron source by using a particle accelerator is a promising tool for actual material analysis,infrastructural diagnostics, nuclear detection, and medical treatment. … We have been operating theneutron source RANS (RIKEN Accelerator-driven compact Neutron Source) with 7 MeV proton LINACwith a beryllium long-life target for 6 years. …

    The Review of Laser Engineering 46(11), 654, 2018


  • Initial Results of Triton Burnup Study in the Large Helical Device

    PU Neng , NISHITANI Takeo , OGAWA Kunihiro , ISOBE Mitsutaka , MURAKAMI Sadayoshi , LHD Experiment Group

    … The neutron yield per shot has reached up to 7 × 10<sup>14 </sup>and 3.5 × 10<sup>15 </sup>in the first phase where NBI #1, 2, and 3 used hydrogen and NBI #4 and 5 used deuterium, and in full D-D phase, respectively. … For the triton burnup study in this campaign, the neutron activation system (NAS) has been used to measure 14 MeV neutrons and 2.45 MeV neutrons. …

    Plasma and Fusion Research 13(0), 3402121-3402121, 2018


  • 3 × 10<sup>8 </sup>D-D Neutron Generation by High-Intensity Laser Irradiation onto the Inner Surface of Spherical CD Shells

    SATOH Nakahiro , ARIKAWA Yasunobu , SUNAHARA Atsushi , HIRONAKA Yoichiro , SHIGEMORI Keisuke , FUJIOKA Shinsuke , NAKAI Mitsuo , AZECHI Hiroshi , WATARI Takeshi , NISHIHARA Katsunobu , MATSUKADO Koji , YOSHIMURA Ryo , AKIYAMA Naoki , TAKAGI Masaru , KAWASHIMA Toshiyuki , ABE Yuki

    … <p>3 × 10<sup>8 </sup>deuterium-deuterium (D-D) neutron generation per pulse was achieved with one-sided laser irradiation through an inlet hole of a deuterated polystyrene shell and a laser intensity of (2-3) × 10<sup>16 </sup>W/cm<sup>2</sup>. … Neutron time-of-flight spectra were recorded at three different angles from the laser incident axis to investigate the directional dependence. …

    Plasma and Fusion Research 13(0), 2401028-2401028, 2018


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