A MINIMAL DYNAMICAL MODEL OF EDGE LOCALIZED MODE PHENOMENA
A MINIMAL DYNAMICAL MODEL OF EDGE LOCALIZED MODE PHENOMENA
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DOI：
10.1063/1.871169
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发表时间：
1995-09-01
影响因子：
2.2
通讯作者：
CARRERAS, BA
中科院分区：
文献类型：
--
作者：
LEBEDEV, VB;DIAMOND, PH;CARRERAS, BA
提出了一种简单的低维边缘局域模（ELM）模型。ELM动力学由托卡马克等离子体边缘的几个基本过程的相互作用决定;这些过程包括磁流体动力学（MHD）压力梯度驱动的不稳定性的演化、低-高（L-H）转变（由电场剪切诱导的抑制和产生介导）、中性粒子对边缘的加燃料以及来自核心等离子体的热通量对边缘的加热。在H模式等离子体的参数区域特征中，该模型表现出向稳态弛豫振荡的转变（即，稳定极限环行为）。研究了ELM的频率、振幅等与加热功率P-in等控制参数的关系。从巨人到草ELM行为的过渡似乎是随着P-in的增加而逐渐边缘稳定到理想膨胀的结果。还揭示了ELM开始的动力学和接近L-H转变阈值的行为的一些细节。(C)1995年美国物理学会。
A simple, low-dimensional model of edge localized mode (ELM) phenomena is presented. ELM dynamics are determined by the interaction of few basic processes at the edge of tokamak plasma; these include the evolution of magnetohydrodynamic (MHD) pressure gradient driven instabilities, the low-high (L-H) transition (mediated by electric field shear induced suppression and generation), the fueling of the edge by neutral particles, and edge heating by thermal flux from the core plasma. In the parameter regime characteristic of an H-mode plasma, the model exhibits a transition to stationary relaxation oscillations (i.e., stable limit cycle behavior) corresponding to ELMs. The dependence of ELM frequency, amplitude, etc. on the heating power P-in and other control parameters is studied. The transition from giant to grassy ELM behavior appears as a consequence of increasingly marginal stability to ideal ballooning as P-in increases. Several details of the dynamics of the ELM onset and behavior close to the L-H transition threshold are revealed, as well. (C) 1995 American Institute of Physics.