New Concepts of Transport Physics in Toroidal Plasmas
New Concepts of Transport Physics in Toroidal Plasmas
复制标题
环形等离子体输运物理的新概念
DOI：
10.1088/0741-3335/57/4/044007
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发表时间：
2015
影响因子：
2.2
通讯作者：
K. Ida
中科院分区：
文献类型：
--
作者：
Y. Fujiki;C. Nagai;L. Oxarango;and T. Mukunoki;T.;上野道雄;伊藤 悟;K. Ida
综述了环形等离子体输运物理的新概念。输运的非扩散和非定域性的输运特性已经被认为是决定密度、旋转和温度的径向结构以及通量-梯度关系中的非线性的重要因素。动量输运的非扩散项表现为“自发转动和本征扭矩”，而粒子输运的非扩散项表现为“粒子夹持和粒子排气”。已发现这些非扩散项的符号和大小对引起反转现象的湍流状态很敏感。在动量输运中，即使等离子体参数稍有变化，通常也能观察到从co(平行于等离子体流)方向到反(反平行于等离子体流)方向的自发流动反转。在粒子输运中，特别是在杂质输运中，环形等离子体中也观察到了由内向外的对流径向通量的逆转，表现为密度峰值/平坦化和杂质聚集/排出现象。在对微扰的响应中观察到了输运的非定域性，例如与边缘的弹丸冷却相关的核心温升，不同半径输运的强耦合，如ITB的曲率转变，以及ITB区域的空间传播。实验证实了具有中尺度和长关联的湍流是引起输运非定域性的重要因素，并且在各种装置中也发现了不同湍流尺度之间的耦合。
New concepts of transport physics in toroidal plasmas is reviewed. The transport characteristics of non-diffusion and non-locality of transport has been recognized to be important in determining radial structures of density, rotation, and temperature, as well as non-linearity in the flux-gradient relation. The non-diffusive term of momentum transport appears as a'spontaneous rotation and intrinsic torque', while the non-diffusive term of particle transport appears as a'particle pinch and particle exhaust'. The sign and magnitude of these non-diffusive terms have been found to be sensitive to the turbulence state, which causes reversal phenomena. In the momentum transport, the spontaneous flow reversal from the co-(parallel to plasma current) direction to the counter-(anti-parallel to plasma current) direction and vice versa have been commonly observed even when the plasma parameter changes slightly. In the particle transport, especially in the impurity transport, reversals of convective radial flux from inward to outward are also observed in toroidal plasmas as phenomena of density peaking/flattening and impurity accumulation/exhaust. Non-locality of transport has been observed in the response to perturbations, such as a core temperature rise associated with the cooling at edge by pellet injection, strong coupling of transport at different radii as seen in the curvature transition of ITB, and spatial propagation of ITB regions. The turbulence with meso-scale and long correlation, which are strong candidates for causing the non-locality of the transport, have been confirmed experimentally and the coupling between the different turbulence scales has also been identified in various devices.