Vacuum modeling of three-dimensional magnetic field topology under resonant magnetic perturbations on EAST
Vacuum modeling of three-dimensional magnetic field topology under resonant magnetic perturbations on EAST
复制标题
EAST 共振磁扰动下三维磁场拓扑的真空建模
DOI：
10.1088/0741-3335/58/5/055010
复制
发表时间：
2016
影响因子：
2.2
通讯作者：
Shen B.
中科院分区：
文献类型：
--
作者：
Jia M.;Sun Y.;Zhong F.;Li H.;Li G.;Wang L.;Gan K.;Zhang B.;Qian J.;Shen B.
提出了一种基于场线追踪的共振磁扰动下先进超导托卡马克（EAST）三维磁场拓扑的数值模型。拓扑结构的计算在真空范例。模拟结果预测，在不同位置的诊断中，可以观察到面向等离子体的组件上可能的撞击点分裂和边界上的叶状结构。结果表明，具有共振主谱的磁扰动不仅可以产生大的随机层，而且可以产生大的足迹分裂效应。这对于使用具有有限空间分辨率的诊断的观测是有用的。研究了RMP字段对边缘断开的双空配置的影响。为了避免上偏滤器或上x点附近面向等离子体的组件上的瞬态热负荷，有必要保持近双零配置的两个分离面之间的距离大于取决于RMP强度和平衡性质的阈值。在EAST上进行的初步RMP实验表明，该程序预测的分裂宽度与偏滤器探测器测量的粒子通量吻合得很好。在RMP阶段，观察到在较低的单零放电的粒子通量的增强上偏滤器。
A numerical model using field line tracing for modeling of three-dimensional magnetic field topology under resonant magnetic perturbations (RMPs) on experimental advanced superconducting tokamak (EAST) is presented. The topological structure is calculated in the vacuum paradigm. The modeling result predicts that the possible strike point splitting on a plasma-facing component and the lobes-like structure on the boundary are observable in the diagnostics at different locations. It is shown that the magnetic perturbations with a resonant dominant spectrum can induce a large footprint splitting effect as well as a wide stochastic layer. This is useful for observations using diagnostics with limited spatial resolution. The impact of RMP fields on marginally disconnected double null configurations is investigated. To avoid the transient heat load on the upper divertor or plasma-facing components near the upper x-point, it is necessary to keep the distance between two separatrices of a near double null configuration larger than a threshold value that depends on the RMP strength and the equilibrium properties. A preliminary RMP experiment on EAST shows that there is a good agreement between the splitting width predicted by the code and that of the particle flux measured by divertor probes. An enhancement of particle flux on the upper divertor during the RMP phase is observed in the lower single null discharge.