具有大拉长比位形的等离子体在垂直方向是极不稳定的。当等离子体失去控制向上或向下移动时，就会在周围诱发大量的HALO电流，当HALO电流随着等离子体碰壁流向托卡马克内部结构后，和强大纵场相互作用，会对内部结构偏滤器部分产生巨大的电磁力,这对目前各大装置以及今后的反应堆都有巨大的危害。而HALO电流的物理成因目前尚不是非常清晰，因此该问题的研究显得尤为关键。基于此，我们将在EAST装置上展开有关HALO电流的实验研究，通过安装在上铜钨偏滤器和下石墨偏滤器区域的罗柯线圈测量详细地HALO电流幅值、电流回路和分布特性，结合理论模型，尝试解决HALO电流的物理机制以及环形不对称性研究，并结合环向多组实验测量数据分析HALO电流旋转频率与环向不对称因子之间的关系。

Plasmas with elongated cross-section are vertically unstable. A large of halo current will be induced in the surface of plasma, when the vertical displacement event. The currents flow into inner components as the plasma touch the first wall in the divertor area. a huge electromagnetic force will be acted on the divertor. It will be serious damage to the device. Now the physics of halo current is not very clear. In the project, we will study the halo current behavious on EAST tokamak. Lots rogowski coils will be installled in the area of up and down divertor to measure the value and profile of HALO current, and investigate the halo current rotation frequency, and compare it with toroidal peaking factor via toroidal halo current sensors.