Impact of RMP magnetic field simulation models on fast ion losses
Impact of RMP magnetic field simulation models on fast ion losses
复制标题
DOI：
10.1088/0029-5515/55/1/012001
复制
发表时间：
2014
期刊：
影响因子：
3.3
通讯作者：
D. Pfefferlé;C. Misev;W. A. Cooper;J. Graves
中科院分区：
文献类型：
--
作者：
D. Pfefferlé;C. Misev;W. A. Cooper;J. Graves
比较了在快离子模拟中考虑共振磁扰动(RMP)的两种不同方法，一种是将RMP电流线圈产生的真空场添加到轴对称的MHD平衡中，另一种是在其磁通表面的三维形变中包括等离子体响应。第一个模型允许大范围的随机场线不经改变地穿透等离子体。第二种方法采用具有单个磁轴的嵌套磁通面，排除了随机场线，并将RMP嵌入到3D饱和理想MHD态中。关于核动力源的两种描述已在金星-利维斯制导中心轨道代码中实施。对MAST中性束注入产生的快离子布居进行了模拟，得到了MAST n=3RMP线圈结构。在低能时，由于场线的随机性，粒子损失主要由平行输运主导(真空-RMP模型)，而在较高能量时，损失归因于扰动等离子体的三维结构和由此产生的漂移(平衡-RMP模型)。
Two opposing approaches to include resonant magnetic perturbations (RMPs) in fast ion simulations are compared, one where the vacuum field caused by the RMP current coils is added to the axisymmetric MHD equilibrium, the other where the MHD equilibrium includes the plasma response within the 3D deformation of its flux-surfaces. The first model admits large regions of stochastic field-lines that penetrate the plasma without alteration. The second assumes nested flux-surfaces with a single magnetic axis, which excludes stochastic field-lines, and embeds the RMPs within a 3D saturated ideal MHD state. The two descriptions of RMPs have been implemented in the VENUS-LEVIS guiding-centre orbit code. Simulations of fast ion populations resulting from MAST neutral beam injection have been applied to MAST n = 3 RMP coil configuration. At low beam energies, particle losses are dominated by parallel transport due to the stochasticity of the field-lines (vacuum-RMP model), whereas at higher energies, losses are accredited to the 3D structure of the perturbed plasma and the resulting drifts (equilibrium-RMP model).