EAST高约束等离子体对外部磁扰动响应的磁流体模拟

In tokamak, it is inevitable to have the very small pertubed magnetic field, named error field. These small 3D magnetic perturbations have substantial impacts on the plasma equilibrium,stability,confinement and transport. Abundant 3D magnetic perturbations related experimental results demonstrate that the plasma response to external applied magnetic field plays a vital role. Multifunctional magnetic perturbation coils have been installed on the EAST superconducting tokamak and is about to launch a three-dimensional magnetic perturbation related experiments. We will use a linear MHD code MARS-F to carry out closely related with experiments response modelling. We will investigate effects from plasma parameters and perturbed field parameters , such as the upper-lower coil current phase , q95 and beta on plasma response. Resonant field amplification will be explored. Modelling closely combined with experiments would directly support related experiments and also improve the understanding of 3D relevant physics. Understanding on different plasma how to respond to different configurations external error field will shed light on mechanism of ELM suppression by RMP. It is also beneficial to realization of high perfomance steady state discharge in tokamak.

比平衡磁场小很多的误差场在托卡马克中不可避免，这些三维磁扰动对等离子体平衡、稳定性、约束和输运有着重要的影响。已有的丰富的三维磁扰动物理实验结果表明等离子体对外加扰动磁场的响应对真正理解三维磁扰动产生的物理效果非常关键。EAST超导托卡马克上已经安装了多功能磁扰动线圈，即将系统开展托卡马克中的三维磁扰动物理实验。本课题将运用线性磁流体程序MARS-F开展EAST实验关心和急需的等离子体线性响应模拟，主要包括等离子体参数和扰动场参数，如线圈电流相位差、q95和比压等对高约束等离子体响应的影响；共振场放大规律的探索；被动板对三维平衡的影响等。结合实验的模拟研究将直接支持相关实验的开展并推动三维相关物理的理解，不同等离子体如何对不同外部磁扰动做出不同类型响应的研究对理解边界局域模的抑制机理、误差场补偿实现稳态高参数放电等有着有重要意义。

外部共振磁扰动对等离子体平衡、稳定性、约束和输运有着重要的影响，EAST超导托卡马克上已经安装多功能磁扰动线圈并开展了系列研究。在基金的资助下，项目执行期间与实验人员合作开展了等离子体对外部扰动磁场响应以及外部共振磁扰动弱化、控制边界局域模的实验与模拟研究。运用轨道跟踪程序数值模拟研究了类EAST位形中的共振磁扰动引起的高能粒子的损失和再分布。在项目资助下采用高精度、高分辨的现代数值计算格式完全独立自主成功研发基于守恒扰动形式磁流体模型的数值模拟程序，在成功完成程序验证后研究了磁约束等离子体中关心的双撕裂模中的二级磁岛演化过程。