Physics of anomalous transport and confinement improvement

异常传输和限制改进的物理学

• 批准号: 09044111
• 负责人: IDA Katsumi
• 金额: $ 2.69万
• 依托单位: National Institute for Fusion Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09044111/
• 关键词: Self sustained transport model; Theory of confinement improvement; Theory of collapse phenomena; Non local transport model; Helical system; Momentum Transport; Spontaneous potential Bifurcation; Internal Transport Barrier; トロイダル・プラズマ; 乱流輸送; 異常輸送

Theoretical research results are (1) Development of self sustained transport model (critical turbulence characteristics, spectral. turbulence), (2) Theory of confinement improvement and guideline for helical system (3) Theory of collapse phenomena.(4)Development of non local transport model. Experimental results are (5) Finding of confinement improvement in Helical system (6) Research of momentum transport (7) Bifurcation of radial electric field. Experimental evidence of micro turbulence in the scale of collisionless electron decay length.The bifurcation surface of radial electric field is predicted theoretically in the structure of radial electric field in torus plasma. The radial electric field bifurcation surface is the surface between the strong positive radial electric field and negative (orweak positive) radial electric field. It is theoretically predicted that the anomalous transport is reduced in the region where the gradient of radial electric field is strong. Theoretically i … More nternal transport barrier is predicted to be produced by this mechanism in helical system.In the conventional anomalous transport mode, the hat flux crossing the magnetic flux is expressed with local plasma parameter at the magnetic flux surface. In the theoretical frame work, it is difficult to explain the fast response for external trigger observed in W7AS device.New non-local transport model is proposed by analyzing the observation in W7AS.The heat flux across the magnetic flux surface is affected by the radial profile of plasma because of the turbulence of long wavelength comparable to the plasma size, In the self sustained transport model, the transition of one turbulence to the other is predicted and theory of collapse phenomena such as ELMs and internal transport barrier collapse is proposed.There is significant development of experiment research. In CHS the transition between the two different profiles of electric potential was observed. This is the first observation for spontaneous electric potential bifurcation in toroidal plasma and supports the hypnosis of bifurcation of radial electric field. The transition between two profiles are continuous and give the impact to steady state helical plasma.These bifurcation is predicted in tokamak plasma as well as helical plasma and plasma flow due to the plasma pressure is theoretically predicted in the momentum transport. The detail experiments on this issue has been done and the relation between the gradient of flow velocity and momentum flux is studied. It is clearly demonstrated that the momentum flux not due to the gradient of flow but the gradient of ion pressure or ion temperature exists in the momentum transport. Less

理论研究成果有：（1）发展了自维持输运模式（临界湍流特性、谱。（2）约束改善理论和螺旋系统的准则;（3）塌缩现象理论。（4）非局部输运模型的发展。实验结果包括：（5）螺旋系统约束改善的发现;（6）动量输运的研究;（7）径向电场的分叉。无碰撞电子衰减长度尺度下微观湍流的实验证据在环面等离子体径向电场结构中，从理论上预测了径向电场的分叉面。径向电场分叉面是强正径向电场和负（或弱正）径向电场之间的表面。从理论上预测，在径向电场梯度较强的区域，反常输运减弱。理论上我 ...更多信息 在传统的反常输运模式中，穿过磁通量的帽通量用磁通量表面的局域等离子体参数来表示。针对W7 AS装置中观测到的外触发快速响应现象，在理论框架下难以解释的问题，通过对W7 AS装置中观测到的外触发快速响应现象的分析，提出了新的非局域输运模型：由于与等离子体尺寸相当的长波长湍流，穿过磁通表面的热通量受到等离子体径向分布的影响，在自持输运模型中，预测了一种湍流向另一种湍流的转变，提出了ELMs和内输运势垒坍塌等坍塌现象的理论，实验研究取得了重大进展。在CHS中，观察到两种不同电位分布之间的过渡。这是首次在环形等离子体中观察到自发电位分岔，支持了径向电场分岔的假说。在托卡马克等离子体和螺旋等离子体中，由于等离子体压力的影响，在动量输运中从理论上预测了这些分叉。本文对这一问题进行了详细的实验研究，研究了流速梯度与动量通量的关系。结果表明，动量输运中存在的动量通量不是由流动梯度引起的，而是由离子压力梯度或离子温度梯度引起的。少

项目成果

K.ITOH, et al.: "Generation of Toroidal Current sheet at Sawtooth crash" Plasma Phys.Contr.Fusion. 39. 1033-1039 (1997)

K.ITOH 等人：“锯齿碰撞时环形电流片的生成”Plasma Phys.Contr.Fusion。

S.-I.ITOH, et al.: "Physics of collapse-probolrilistic occurence of ELMS and Crashes" Plasma Phys.Contr.Fusion. 40(印刷中). (1998)

S.-I.ITOH 等人：“ELMS 和崩溃的崩溃概率发生的物理学”Plasma Phys.Contr.Fusion 40（出版中）。

H.Sanuki: "Studies on wave analysis and electric field in plasmas in Frontier of Physics in Fusion-Relevant Plasmas" World Scientific, Singapore, (1998)

H.Sanuki：“聚变相关等离子体物理学前沿中等离子体波分析和电场的研究”世界科学，新加坡，（1998 年）

S.-I.ITOH, K.ITOH: "Spectrum of subcritical turbulence in an inhomageneous plasma" J.Phys.Soc.Jpn.66. 1571-1574 (1997)

S.-I.ITOH、K.ITOH：“非均匀等离子体中的亚临界湍流谱”J.Phys.Soc.Jpn.66。

T.Kubota, S.-I.Itoh, et al.: "1D Simulation of Sawtooth crash based on transport bifurcation" Plasma Phys.Contr.Fusion. 39. 1397-1407 (1997)

T.Kubota、S.-I.Itoh 等人：“基于传输分叉的锯齿碰撞的一维模拟”Plasma Phys.Contr.Fusion。