On the dynamics of edge-core coupling
On the dynamics of edge-core coupling
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DOI：
10.1063/1.2034307
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发表时间：
2005-09-01
影响因子：
2.2
通讯作者：
Ethier, S
中科院分区：
文献类型：
--
作者：
Hahm, TS;Diamond, PH;Ethier, S
在核聚变理论中，一个令人困扰的、尚未解决的问题是边缘的范围。用回旋粒子程序模拟环形离子温度梯度湍流扩展[Z. Lin，T. S.嗯，W。W.李，W。M. Tang，和R. B。白色，科学281，1835（1998）]及其相关的动力学模型已被推广到一个系统的径向变化的离子温度梯度，以研究的边缘湍流向核心等离子体的向内扩展。由于这种扩散，核心区域中的湍流强度比仅从核心区域的模拟获得的值显著增强，并且边缘区域的精确边界模糊。即使当芯梯度在Dimits移位范围内（即，由自生的带状流支配，其将输送减少到可忽略的值），由于从边缘扩散，显著水平的湍流可以穿透到核心。湍流锋面传播速度的标度比基于线性环形耦合的模型更接近于非线性扩散模型的预测。(C)2005年美国物理学会。
One of the nagging, unresolved questions in fusion theory is concerned with the extent of the edge. Gyrokinetic particle simulations of toroidal ion temperature gradient turbulence spreading using the gyrokinetic toroidal code [Z. Lin, T. S. Hahm, W. W. Lee, W. M. Tang, and R. B. White, Science 281, 1835 (1998)] and its related dynamical model have been extended to a system with radially varying ion temperature gradient, in order to study the inward spreading of edge turbulence toward the core plasma. Due to such spreading, the turbulence intensity in the core region is significantly enhanced over the value obtained from the simulations of the core region only, and the precise boundary of the edge region is blurred. Even when the core gradient is within the Dimits shift regime (i.e., dominated by self-generated zonal flows which reduce the transport to a negligible value), a significant level of turbulence can penetrate to the core due to spreading from the edge. The scaling of the turbulent front propagation speed is closer to the prediction from a nonlinear diffusion model than from the one based on linear toroidal coupling. (C) 2005 American Institute of Physics.