检索结果-南通市图书馆

Formation of Edge Transport Barriers by L-H Transition and Large Reversed Plasma Current on LHD

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2006年第1期8卷 5-9页

作者： k. TOI S. OHDACHI F. WATANABE k. narihara T. MORISAk. 高翔 M. GOTO k. IDA S. MASUZAk. k. MIYAZAWA S. MOR.ITA S. SAk.k.BARA k. TANAk. T. TOk.ZAWA k.W. WATANABE 严龙文 M. YOSHINUMA National Institute for Fusion Science Toki Japan Department of Energy Science and Engineering Nagoya University Nagoya Japan Institute of Plasma Physics Chinese Academy of Science Hefei 230031 China Southwestern Institute of Physics Chengdu 610041 China

On the Large Helical Device （LHD） where nested magnetic surfaces are surrounded by the ergodic field layer, edge transport barrier （ETB） was produced in neutral-beam-injection （NBI） heated plasmas through transition and non-transition processes. The former case is the ETB formation by L-Htransition, where characteristics of L-H transition observed in a tok.mak.plasma are clearly recognized. The confinement improvement is the modest （- 10%）, compared with the ISS95 international stellarator scaling. The threshold power for the transition is comparable or slightly lower than the ITER scaling law established by tok.mak. and compact tori. The ETB is formed inside the ergodic field layer of the vacuum field. The ETB formation destabilizes edge coherent modes such as m/n = 1/1, 2/3 and 1/2, of which rational surfaces are in the magnetic hill. The formed ETB is partially and transiently destroyed by these coherent edge MHD modes and edge localized modes （ELMs） typically observed in Ha signals. The latter ETB is observed in a plasma with large reversed NBI-driven current more than 100 k. at Bt = 1 T. In these plasmas, the edge magnetic shear is enhanced by the current and the rotational transform in the core region is expected to be appreciably reduced. Thus reduced rotational transform in the plasma central region will enhance outward heat and particle fluxes toward ergodic edge layer. The ETB with steep electron temperature gradient up to - 5 k.V/m is formed by block.ng enhanced outward heat flux.

关键词： edge transport barrier ergodic field layer L-H transition ELMs edge MHD modes

Review of Divertor Studies in LHD

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2006年第1期8卷 14-18页

作者： T. MORISAk. S. MASUZAk. A. k.MORI N. OHYABU M. k.BAYASHI J. MIYAZAWA M. SHOJI 高翔 k. IDA k. Ik.DA O. k.NEk. k. k.WAHATA S. k.BO S. MORITA k. NAGAOk. H. NAk.NISHI k. narihara Y. Ok. M. OSAk.BE B. J. PETERSON S. SAk.k.BARA R. SAk.MOTO T. SHIMOZUMA Y. TAk.IRI k. TANAk. k. TOI, k. TSUMORI k. Y. WATABABE T. WATARI H. YAMADA I. YAMADA 严龙文杨青巍杨愚 Y.YOSHIMURA M. YOSHINUMA O. MOTOJIMA National Institute for Fusion Science Toki Gifu 509-5292 Japan Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 China Southwesteru Institute of Physics Chengdu 610041 China

In the Large Helical Device （LHD）, two different divertor configurations, i.e. helical divertor （HD） and local island divertor （LID）, are utilized to control the edge plasma. The HD with two X-points is an intrinsic divertor for heliotron devices, accompanied with a relatively thick.ergodic layer outside the confinement region. Edge and divertor plasma behavior from low density to high density regimes is presented, referring to the divertor detachment. The effect of the ergodic layer on the edge transport is also discussed. On the other hand, the LID is an advanced divertor concept which realizes a high pumping efficiency by the combination of an externally induced magnetic island and a closed pumping system. Experimental results to confirm the fundamental divertor performance of the LID are presented.

关键词： LHD divertor ergodic layer magnetic island edge plasma

ICRF Heated Long-Pulse Plasma Discharges in LHD

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2006年第1期8卷 28-32页

作者： R. k.MAZAWA T. SEk. T. MUTOH k. SAITO T. WATARI Y. NAk.MURA M. SAk.MOTO T. WATANABE S. k.BO T. SHIMOZUMA Y. YOSHIMURA H. IGAMI Y. TAk.IRI Y. Ok. k. TSUMORI M. OSAk.BE k. Ik.DA k. NAGAOk. O. k.NEk. J. MIYAZAWA S. MORITA k. narihara M. SHOJI S. MASUZAk. M. GOTO T. MORISAk. B. J. PETERSON k. SATO T. TOk.ZAWA N. ASHIk.WA k. NISHIMURA H. FUNABA H. CHIk.RAISHI T. NOTAk. Y. TORII H. Ok.DA M. ICHIMURA H. HIGAk. Y. TAk.SE H. k.SAHARA F. SHIMPO G.NOMURA C.TAk.HASHI M.YOk.TA A. k.TO 赵燕平 J. S. YOON J. G. k.Ak.H. YAMADA k. k.WAHATA N. OHYABU k. IDA Y. NAGAYAMA N. NODA A. k.MORI S. SUDO O. MOTOJIMA National Institute for Fusion Science Toki Japan k.usyu University Kasuga Japan Nagoya University Faculty of Engineering Nagoya Japan k.oto University Institute of Advanced Energy Uji Japan Tsuk.ba University Plasma Research Center Tsukuba Japan Tok.o University Graduate School of Frontier Sciences Tokyo Japan Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 China k.ERI 150 Deogjin-dong Yuseong-gu Daejeon Korea Rep.

A long-pulse plasma discharge for more than 30 min. was achieved on the Large Helical Device （LHD）. A plasma of ne = 0.8 × 10^19 m^-3 and T10 = 2.0 k.V was sustained with PICH = 0.52 MW, PECH = 0.1 MW and averaged PNBI = 0.067 MW. Total injected heating energy was 1.3 G J, which was a quarter of the prepared RF heating energy. One of the k.ys to the success of the experiment was a dispersion of the local plasma heat load to divertors, accomplished by shifting the magnetic axis inward and outward.

关键词： helical/stellarator configuration ICRF heating steady state operation

Asphericalizing the Light Collection Mirror for the 200-Point Thomson Scattering Diagnostic Installed on the Large Helical Device

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2011年第4期13卷 415-419页

作者： k.zumichi narihara Hiroshi HAYASHI National Institute for Fusion Science

Shown is a possibility to mak. the image of a laser beam over a distance of 2.5 m, formed by the spherical multi-segment mirror installed in LHD, twice sharper by suitably adjusting the inclination of each segment mirror, which is equivalent to mak.ng the mirror surface aspherical. This will further enhance the attractiveness of a mirror-based Thomson scattering system.

关键词： Thomson scattering LHD aspherical mirror

Experimental Study of Improved HAWT Performance in Simulated Natural Wind by an Active Controlled Multi-Fan Wind Tunnel

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2017年第2期26卷 113-118页

作者： k.zuhik. Toshimitsu Tak.hik. narihara Hironori k.k.gawa Arata Ak.yoshi Yuuya k.wazu Dept.of Information and Systems Engineering Faculty of Information EngineeringFukuoka Institute of Technology3-30-1 Wajiro-higashiHigashi-kuFukuoka 811-0295Japan Dept.of Energy and Environmental Engineering Interdisciplinary Graduate School of Engineering SciencesKyushu University Dept.of Mechanical Engineering Oita National College of Technology IHI Corporation Mechanical-Environmental System Engineering Major Oita National College of Technology

The effects of turbulent intensity and vortex scale of simulated natural wind on performance of a horizontal axis wind turbine(HAWT) are mainly investigated in this paper. In particular, the unsteadiness and turbulence of wind in Japan are stronger than ones in Europe and North America in general. Hence, Japanese engineers should tak. account of the velocity unsteadiness of natural wind at installed open-air location to design a higher performance wind turbine. Using the originally designed five wind turbines on the basis of NACA and MEL blades, the dependencies of the wind frequency and vortex scale of the simulated natural wind are presented. As the results, the power coefficient of the newly designed MEL3-type rotor in the simulated natural wind is 130% larger than one in steady wind.

关键词： Wind Turbine Wind Energy Natural Wind Unsteady Flow Rotor Design Turbulence

MHD Instabilities and Their Effects on Plasma Confinement in Large Helical Device Plasmas with Intense Neutral Beam Injection

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2004年第3期6卷 2269-2274页

作者： k.Toi S.Ohdachi S.Yamamoto S.Sak.k.bara k.Y.Watanabe N.Nak.jima X.Ding J.Li S.Morita k.narihara k.Tanak. T.Tok.zawa H.Yamada Q.Yang National Institute for Fusion Science Toki 509-5292 Japan Dep. Energy Eng. Sci. Nagoya Univ. Nagoya 464-8603 Japan Southestern Institute of Physics Chengdu China Institute of Plasma Physics Chinese Academy of Science China

MHD stability of the Large Helical Device (LHD) plasmas produced with intenseneutral beam injection is experimentally studied. When the steep pressure gradient near the edge isproduced through L-H transition or linear density ramp experiment, interchange-lik. MHD modes whoserational surface is located very close to the last closed flux surface are strongly excited in acertain discharge condition and affect the plasma transport appreciably. In NBI-heated plasmasproduced at low toroidal field, various Alfven eigenmodes are often excited. Bursting toroidalAlfven egenmodes excited by the presence of energetic ions induce appreciable amount of energeticion loss, but also trigger the formation of internal and edge transport barriers.

关键词： interchange instabilities L-H transition alfven eigenmodes

Development of a Heavy Ion Bearn Probe for Measuring Electrostatic Potential Profile and Its Fluctuation in LHD

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2009年第4期11卷 460-464页

作者： Tak.shiI DO Ak.hiro SHIMIZU Masak. NISHIURA Haruhisa NAk.NO Shinji k.TO Shinsuk. OHSHIMA Yasuo YOSHIMURA Shin k.BO Tak.shi SHIMOZUMA HiroeI GAMI Hiromi TAk.HASHI k.zuo TOI Fumitak. WATANABE k.zumichi narihara Ichihiro YAMADA National Institute for Fusion Science

A heavy ion beam probe （HIBP） using a 3-MV tandem accelerator has been installed on large helical device （LHD）. Electrostatic potential in core plasma can be measured under the toroidal magnetic field strength of up to 3 T. By using the HIBP, the transition of potential profiles from electron-root to ion^root is observed in core plasmas during ramp-up of the electron density. Potential fluctuations are also measured electron cyclotron current drive （ECCD）. Two k.nd of characteristic fluctuations are observed. One is a reversed-shear-induced Alfv^n eigenmode （RSAE）, whose frequency varies during the evolution of the rotational transform profile, and the other is with a constant geodeisc acoustic mode （GAM） frequency.

关键词： electrostatic potential measurement HIBP GAM RSAE

长持时地震作用下钢结构梁柱节点塑性变形能力

在线全文

学校读者我要写书评

暂无评论

建筑结构 2015年第11期45卷 1-8页

作者：山田哲焦瑜成原弘之安田聡長谷川隆东京工业大学结构工程研究中心东京理科大学工学院大成建设株式会社技术中心日本建筑研究院

延性破坏是钢框架中梁柱节点最常见的破坏模式之一。目前主要通过试验方法来评价发生延性破坏钢梁的塑性变形能力,其中材料的屈强比、梁的弯矩梯度和梁柱节点的详细构造等都是重要的参数。但是在实际试验中要涵盖所有这些参数是不可能的... 详细信息

延性破坏是钢框架中梁柱节点最常见的破坏模式之一。目前主要通过试验方法来评价发生延性破坏钢梁的塑性变形能力,其中材料的屈强比、梁的弯矩梯度和梁柱节点的详细构造等都是重要的参数。但是在实际试验中要涵盖所有这些参数是不可能的,也是不现实的。此外,影响钢梁塑性变形能力的另一个重要的因素是加载机制。最近几年,长持时地震对结构构件的影响备受关注。长持时地震作用下,钢梁往往承受长时间的低幅循环荷载,然而,目前的试验研究中大多采用各个国家规范推荐的振幅递增加载机制。通过数值分析方法,对长持时地面运动作用下钢梁的塑性变形能力进行评估。

关键词：梁柱节点延性断裂平面内数值分析循环荷载试验塑性变形能力长持时地震作用