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)发展了自持输运模型(临界湍流特征，谱)。湍流)，(2)约束改善理论和螺旋系统准则(3)坍塌现象理论。(4)非局部输运模型的发展。实验结果是：(5)发现螺旋系统的约束改善；(6)动量输运的研究；(7)径向电场的分叉。在无碰撞电子衰变长度尺度上存在微观湍流的实验证据。从理论上预测了环形等离子体中径向电场结构中的径向电场分岔面。径向电场分岔面是强正向径向电场与负(或弱正)径向电场之间的表面。从理论上预测，在径向电场梯度较大的区域，反常输运减少。理论上讲，I…在常规的反常输运模式下，穿过磁通的HAT通量用磁通面上的局域等离子体参数来表示。在理论框架下，很难解释W7AS器件中观测到的外部触发的快速响应。通过分析W7AS中的观测，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湍流，穿过磁通量表面的热通量受到等离子体径向轮廓的影响。在自维持输运模型中，预测了一种湍流到另一种湍流的转变，并提出了ELMS和内部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，观察到了两种不同的电势分布之间的转变。这是首次观测到环形等离子体中的自发电势分叉，支持了径向电场分叉的催眠机制。在托卡马克等离子体和螺旋等离子体中预测了这种分叉，并从理论上预测了动量输运中由于等离子体压力引起的等离子体流动。对这一问题进行了详细的实验，研究了流速梯度与动量通量之间的关系。结果表明，在动量输运过程中，动量通量不是由流动的梯度引起的，而是离子压力或离子温度的梯度。较少

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。