Analysing the impact of anisotropy pressure on tokamak equilibria
Analysing the impact of anisotropy pressure on tokamak equilibria
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DOI：
10.1088/0741-3335/56/7/075007
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发表时间：
2014-01
影响因子：
2.2
通讯作者：
Z. Qu;Michael Fitzgerald;M. Hole
中科院分区：
文献类型：
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作者：
Z. Qu;Michael Fitzgerald;M. Hole
中性束注入和离子回旋共振加热引起压力各向异性。对轴对称等离子体平衡程序HELENA进行了改进，使之包括各向异性和环形流。我们已经研究了，使用分析和数值方法，各向异性平衡的决定因素和它们对通量表面的影响，磁轴的移位，以及压力和密度等值线从通量表面的位移。当p/p = 1.5时，在类MAST（MAST：Mega Spherical Tokamak）平衡中，p在s = 0.5通量面上可以变化20%。我们还重新评估了广泛应用的各向异性近似，其中p* =（p + p）/2，平行和垂直压力的平均值，被视为近似各向同性压力。我们证明，只有通过给出不正确的RBφ，各向同性重建才能产生正确的p*。我们发现，使用各向同性和各向异性模型的相同的MAST放电与p/p 1.25的重建有3%的差异，在环向场和66%的差异极向电流。
Neutral beam injection and ion cyclotron resonance heating induce pressure anisotropy. The axisymmetric plasma equilibrium code HELENA has been upgraded to include anisotropy and toroidal flow. We have studied, using both analytical and numerical methods, the determining factors for anisotropic equilibria and their impact on flux surfaces, the magnetic axis shift, and the displacement of pressure and density contours from the flux surface. With p∥/p⊥ ≈ 1.5, p⊥ can vary by 20% on the s = 0.5 flux surface, in a MAST-like (MAST: Mega Amp Spherical Tokamak) equilibrium. We have also re-evaluated the widely applied approximation to the anisotropy in which p* = (p∥ + p⊥)/2, the average of the parallel and perpendicular pressures, is taken as the approximate isotropic pressure. We show that an isotropic reconstruction can yield a correct p* only by giving an incorrect RBφ. We find the reconstructions of the same MAST discharge with p∥/p⊥ ≈ 1.25 using isotropic and anisotropic models to have a 3% difference in a toroidal field and a 66% difference for a poloidal current.