Search Results 1-20 of 36

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  • Behavior of a Tracer-Containing Compact Toroid in a Transverse Magnetic Field

    SEKI Taichi , TAMURA Naoki , NARUSHIMA Yoshiro , KOBAYASHI Daichi , SASAKI Rika , MINAMIGI Asuna , ASAI Tomohiko , GOTA Hiroshi , ROCHE Thomas , MATSUMOTO Tadafumi , TAKAHASHI Toshiki

    … A tracer-containing compact toroid (TCCT) injection have been developed as a new tracer injection technique for studying impurity accumulation and behavior in magnetically confined fusion plasmas. … Tracer ions, e.g., tungsten, copper, and aluminum, are supplied by an independently controlled tracer source attached to the CT injector. …

    Plasma and Fusion Research 15(0), 2402069-2402069, 2020

    J-STAGE 

  • 4. Material Science and Radiation Effects

    … Sto et al.(30009) [156]CO4-4 Correlation between Damage Accumulation by Neutron Irradiation and Hydrogen Isotope Retention for Plasma Facing Materials /Y. … Sugita et al.(30076) [170]CO4-18 Recovery Behaviors of Irradiation-Induced Vacancies in Tungsten Probed by Positrons /A. …

    KURNS Progress Report (2018), 154-184, 2019-08

    IR 

  • Expectation from Geochemistry to High-Pressure and High-Temperature Experiments to Elucidate Earth's Geochemical Evolution  [in Japanese]

    SUZUKI Katsuhiko , TAKAMASA Asako , TOKESHI Satoshi

    … A model of the very early history of the earth with accumulation of the planetesimal, the giant impact, core segregation and late veneer has been proposed based on siderophile element abundance and isotopic composition of the old mantle-derived rocks. …

    The Review of High Pressure Science and Technology 27(4), 246-255, 2017

    J-STAGE 

  • Particle Pinch Model of Passing/Trapped High-Z Impurity with Centrifugal Force Effect

    SHIMIZU Yusuke , FUJITA Takaaki , OKAMOTO Atsushi , ARIMOTO Hideki , HAYASHI Nobuhiko , HOSHINO Kazuo , NAKANO Tomohide , HONDA Mitsuru

    <p>The inward pinch model for high-Z impurity ions in a toroidally rotating plasma has been improved to take account of trapped particles and the centrifugal force effect. It is found that the P …

    Plasma and Fusion Research 11(0), 2403082-2403082, 2016

    J-STAGE 

  • Analysis of Tungsten Transport in JT-60U Plasmas

    SHIMIZU Yusuke , FUJITA Takaaki , ARIMOTO Hideki , NAKANO Tomohide , HOSHINO Kazuo , HAYASHI Nobuhiko

    … <p>In JT-60U plasmas, increasing the toroidal rotation opposite to the plasma current (CTR rotation) enhances tungsten accumulation. … We study the dependence of tungsten accumulation on the toroidal rotation in TOTAL simulations of JT-60U plasmas. … The tungsten accumulation was four times higher at high toroidal rotation velocity than at low toroidal rotation velocity, replicating the experimental trend. …

    Plasma and Fusion Research 10(0), 3403062-3403062, 2015

    J-STAGE 

  • Application of Nanostructured Tungsten Fabricated by Helium Plasma Irradiation for Photoinduced Decolorization of Methylene Blue

    Komori Katsuyuki , Yoshida Tomoko , Yagi Shinya , Yoshida Hisao , Yajima Miyuki , Kajita Shin , Ohno Noriyasu

    … The dendritic nanostructure was fabricated on a surface of tungsten plate by helium plasma irradiation. … It is also found that the reaction rate decreased with time, which would be caused by the products accumulation on the surface and the surface oxidation. …

    e-Journal of Surface Science and Nanotechnology 12(0), 343-348, 2014

    J-STAGE 

  • Behaviors of Deuterium Retention and Microstructure Change of Tungsten Simultaneously Implanted with Carbon and/or Helium Ions

    OYA Yasuhisa , KOBAYASHI Makoto , FUJISHIMA Tetsuo , KAWASAKI Kiyotaka , MIYAHARA Yuto , YOSHIDA Naoaki , HATANO Yuji , ASHIKAWA Naoko , SAGARA Akio , OKUNO Kenji

    … Recent studies of deuterium (D) retention and microstructure behaviors of tungsten simultaneously implanted with carbon ion (C<sup>+</sup>) and/or helium ion (He<sup>+</sup>) are reviewed. … However, in the case of triple-ion implantation, the accumulation of C on tungsten was suppressed, and the retention of D trapped by C was reduced. … The D retention in triple-ion-implanted tungsten was considered to be suppressed by He<sup>+</sup> …

    MATERIALS TRANSACTIONS 54(4), 430-436, 2013-04-01

    J-STAGE  References (14)

  • Progress and Issues of Modeling of the Tungsten Impurity Transport  [in Japanese]

    HOSHINO Kazuo

    プラズマ対向壁の損耗や,壁から発生した不純物によるコアプラズマの性能への影響等を評価する上で,シミュレーションの持つ役割は大きい.周辺領域におけるタングステン不純物輸送の解析に対しては,従来のダイバータプラズマや低Z不純物の輸送にも用いられてきたプラズマ流体コードや,運動論的効果や詳細なプラズマ壁相互作用等を取り入れたモンテカルロ法に基づく粒子コードが用いられる.一方,コア領域では,これまでの新古 …

    Journal of plasma and fusion research 87(9), 600-606, 2011-09-25

    NDL Digital Collections  References (15)

  • Progress in Transport and Control Studies of Tungsten in Tokamak Experiments  [in Japanese]

    ASAKURA Nobuyuki , NAKANO Tomohide

    タングステンはITERのダイバータ対向材として設置され,高温壁の原型炉では第一壁材としても考えられているが,高温の炉心プラズマ実験での経験はまだ豊富とは言えず,そのプラズマ中での制御研究が望まれている.本章では,高温で高閉じ込め性能のトカマク・プラズマ実験(ASDEX-Upgrade,JT-60U,Alcator C-MOD,TEXTOR)で進められている,タングステン(およびモリブデン)の発生要 …

    Journal of plasma and fusion research 87(9), 577-590, 2011-09-25

    NDL Digital Collections  References (56)

  • Tritium accumulation in fusion reactor materials and its decontamination (_I_):Tritium accumulation on tungsten and its decontamination  [in Japanese]

    NAKAYAMA Masato , Torikai Yuji , SAITO Makiko , ISOBE Kanetsugu , YAMANISHI Toshihiko

    核融合炉内のトリチウム蓄積量の評価と除染技術開発の一環として,核融合炉材料候補であるタングステンに,573Kから973Kの間でトリチウムガスを曝露し,トリチウムの蓄積量を調べるとともに,表面および内部のトリチウム分布をエッチング法により検証した。また,その除染法を,オートクレーブを用いた除染および加熱脱離による除染法により検討したので報告する。

    Proceedings of Annual / Fall Meetings of Atomic Energy Society of Japan 2011f(0), 720-720, 2011

    J-STAGE 

  • Transport Analysis of High-Z Impurities Including Sawtooth Effects in a Tokamak System

    YAMADA Ikuhiro , YAMAZAKI Kozo , OISHI Tetsutarou , ARIMOTO Hideki , SHOJI Tatsuo

    … The critical levels of impurity concentration in ITER are found to be 4.0 % for carbon, 0.1 % for iron, and 0.008 % for tungsten with respect to electron density. … Forming an internal transport barrier (ITB) for electron density can prevent high-Z impurity accumulation. …

    Plasma and Fusion Research (5), S1022-S1022, 2010

    J-STAGE 

  • Grain Boundary Embrittelement Mechanism due to Very Low Energy Helium Irradiation  [in Japanese]

    馬場 友紹 , 岩切 宏友 , 吉田 直亮 , Baba Tomotsugu , Iwakiri Hirotomo , Yoshida Naoaki

    … In situ transmission electron microscopy study was performed to investigate grain boundary embrittlement mechanism of tungsten due to very low-energy helium irradiation. … In this study, helium accumulation mechanism at grain boundaries was discussed by considering the behavior of vacancy and helium trapping efficiency of impurities. …

    Reports of Research Institute for Applied Mechanics,Kyushu University (129), 165-169, 2005-09

    IR  DOI 

  • EDMed surface property with PCD electrode

    Sharma Anurag , Iwai Manabu , Pang Lee , Sano Sadao , Uematsu Tetsutaro , Suzuki Kiyoshi

    … In the case of the tungsten carbide workpiece, contrary to the expectation, surface roughness deteriorated for the pulse duration te=5 micro s. … This deterioration of the surface roughness is found to be due to an accumulation of carbon from the dielectric oil along with EDM debris on the electrode surface in the region where cobalt is present, creating protrusions on the electrode surface. …

    Proceedings of JSPE Semestrial Meeting 2005A(0), 1109-1110, 2005

    J-STAGE 

  • Fabrication and Characterization of Self-Standing W-Nanodendrites on Insulator SiO2 Substrate by Electron-Beam-Induced Deposition under HVTEM

    Xie Guoqiang , Song Minghui , Mitsuishi Kazutaka , Furuya Kazuo

    … The nucleation and growth of nanodendrite structures are attributed to a mechanism involving charge-up produced on the substrate surface, and the movement of charges to and charge accumulation at the convex surface of the substrate as well as the tips of the deposits. … The as-fabricated nanodendrite structures possess a high crystallinity and a high content of tungsten. …

    Japanese Journal of Applied Physics 44(7B), 5654-5658, 2005

    J-STAGE 

  • Dynamic Simulation of Multiplier Effects of Helium Plasma and Neutron Irradiation on Microstructural Evolution in Tungsten

    Xu Qiu , Yoshida Naoaki , Yoshiie Toshimasa

    … In the present study, multiplier effects of helium plasma and neutron irradiation on microstructural evolution in tungsten were investigated using computer simulations based on a rate theory. … The simulation results revealed the rapid diffusion of helium in tungsten. …

    MATERIALS TRANSACTIONS 46(6), 1255-1260, 2005

    J-STAGE 

  • Techniques to Accumulate Antiprotons and Positrons as a Pioneering Work in Antimatter Science  [in Japanese]

    Torii Hiroyuki , Kuroda Naofumi , Oshima Nagayasu , Yamazaki Yasunori

    … We report on our new techniques which enabled confinement and accumulation of a large number of antiparticles-namely antiprotons and positrons-in an electromagnetic trap. … A new positron accumulation scheme has been invented, where a dense electron plasma is employed as an energy absorber. …

    Butsuri 60(12), 949-956, 2005

    J-STAGE 

  • Techniques to Accumulate Antiprotons and Positrons as a Pioneering Work in Antimatter Science  [in Japanese]

    Torii Hiroyuki , Kuroda Naofumi , Oshima Nagayasu , Yamazaki Yasunori

    … <p>We report on our new techniques which enabled confinement and accumulation of a large number of antiparticles-namely antiprotons and positrons-in an electromagnetic trap. … A new positron accumulation scheme has been invented, where a dense electron plasma is employed as an energy absorber. …

    Butsuri 60(12), 949-956, 2005

    J-STAGE  References (52) Cited by (2)

  • Influence of Pre-Aging on Creep Rupture Strength of Tungsten Alloyed 9%Cr Ferritic Steel and Creep Damage Evaluation by Electrochemical Method  [in Japanese]

    KOMAZAKI Shin-ichi , KISHI Shigeo , SHOJI Tetsuo , KUMAZAWA Tetsuo , HIGUCHI Kojiro , SUZUKI Koshi

    … The influence of pre-aging on creep rupture strength has been investigated to understand the creep damage mechanism of tungsten alloyed 9%Cr ferritic steel KA-STBA29/KA-STPA29. … Based on the results, an electrochemical nondestructive procedure, which quantitatively detected the amount of Laves phase, has been proposed to evaluate creep damage accumulation in the steel. …

    JSME International Journal Series A 45(1), 30-38, 2002-01-01

    J-STAGE  References (10)

  • Plasma Wall Interactions with High Z Wall Materials  [in Japanese]

    TANABE Tetsuo

    … if the high Z impurities once accumulate in the plasma center, they cause a significant radiation loss, which results in disruption, (3)The accumulation is due to changes in transport inside the core plasma and is independent of the release process at the limiter, (4)Prompt redeposition plays a role to reduce the penetration of the high Z impurities into the plasma, (5)Because of high brittleness and hardness, bulk tungsten is difficult to use as a plasma facing material, Thus, a new fabrication method must be …

    Journal of plasma and fusion research 77(2), 97-110, 2001-02-25

    NDL Digital Collections  References (44)

  • SB-06-5(036) Influence of Pre-Aging on Creep Rupture Strength of Tungsten Alloyed 9%Cr Ferritic Steel and Creep Damage Evaluation by Electrochemical Method(Changes in Microstructure 1) :

    KOMAZAKI Shin-ichi , KISHI Shigeo , SHOJI Tetsuo , KUMAZAWA Tetsuo , HIGUCHI Kojiro , SUZUKI Koshi

    … The influence of pre-aging on creep rupture strength has been investigated to understand the creep damage mechanism of tungsten alloyed 9%Cr ferritic steel KA-STBA29/KA-STPA29. … Based on the results, an electrochemical nondestructive procedure, which quantitatively detected the amount of Laves phase, has been proposed to evaluate creep damage accumulation in KA-STBA29/KA-STPA29. …

    Creep : proceedings of the ... international conference on creep and fatigue at elevated temperatures (01-201), 341-345, 2001

    NDL Digital Collections 

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