Momentum transport and plasma rotation profile in toroidal direction in JT-60U L-mode plasmas
Momentum transport and plasma rotation profile in toroidal direction in JT-60U L-mode plasmas
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DOI：
10.1088/0029-5515/47/8/017
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发表时间：
2007-08
期刊：
影响因子：
3.3
通讯作者：
Minoru Yoshida;Y. Koide;H. Takenaga;H. Urano;Naoyuki Oyama;K. Kamiya;Yoshiteru Sakamoto;G. Matsunaga;Yutaka Kamada
中科院分区：
文献类型：
--
作者：
Minoru Yoshida;Y. Koide;H. Takenaga;H. Urano;Naoyuki Oyama;K. Kamiya;Yoshiteru Sakamoto;G. Matsunaga;Yutaka Kamada
在JT-60 U装置上，采用近垂直中性束注入（PERP-NBI）、同切和反切（CTR）NBI，研究了等离子体在环形方向上的动量输运和旋转特性。利用动量源调制，从瞬态分析中计算了动量输运的扩散项和非扩散项。快速离子损失由于环向场涟漪，局部诱导边缘CTR旋转，被用作一种新的动量源。系统地研究了L模等离子体中这些输运系数即环向动量扩散率（χ i）和对流速度（Vconv）的参数依赖关系，以及动量扩散率和热扩散率（χi）之间的关系。环形动量扩散率随加热功率的增加而增加，随等离子体电流的增加而减小。研究了无量纲参数对χ i和χi的影响。观察到χ_i/χ_i与归一化等离子体压强（βN）有明显的相关性。在低β（βN < 0.4）时，由瞬态动量输运分析得到的χ_（max）和Vconv几乎可以再现有无外转矩输入时的环向旋转速度分布。
The characteristics of momentum transport and plasma rotation in the toroidal direction are studied, using near-perpendicular neutral beam injection (PERP-NBI), co tangential and counter (CTR) tangential NBI in JT-60U. Diffusive and non-diffusive terms of momentum transport are evaluated from the transient analysis by using the momentum source modulation. Fast ion losses due to the toroidal field ripple, which locally induces the edge CTR rotation, are used as a novel momentum source. Parameter dependence of these transport coefficients i.e. the toroidal momentum diffusivity (χϕ) and the convection velocity (Vconv), and the relation between momentum and heat diffusivities (χi) are investigated in L-mode plasmas systematically. The toroidal momentum diffusivity increases with increasing heating power and decreases with increasing plasma current. The relation of χϕ and χi to some non-dimensional parameters is investigated. A clear dependence of χϕ/χi on normalized plasma pressure (βN) is observed. It is also found that toroidal rotation velocity profiles in the case with and without external torque input can be almost reproduced by χϕ and Vconv estimated from the transient momentum transport analysis at low β (βN < 0.4).