如何有效控制大幅度边界局域模（ELM）爆发带来的瞬态热负荷是目前磁约束聚变研究亟需解决的关键科学问题。近期EAST在偏滤器杂质注入条件下获得了一种无ELM高约束运行模式，为有效解决偏滤器靶板热负荷问题提供了一种新的途径，但是实现该运行模式的物理机制尚不清楚。本项目将依托EAST实验平台，明确该运行模式的实验参数区间，获得偏滤器杂质注入条件下大幅度type-I ELM行为变化对主要等离子体参数的依赖关系，利用高时空分辨边界诊断，研究偏滤器杂质注入条件下台基结构及涨落模式的演化特征，并借助数值模拟程序，深入理解偏滤器杂质注入影响台基结构以及抑制type-I ELM的物理机制，弄清等离子体宏观约束性能得到维持的原因。期望通过本项目的开展，加深对偏滤器杂质注入条件下台基相关物理的理解，为EAST和CFETR等未来聚变堆实现与辐射偏滤器兼容且维持较高等离子体约束性能的ELM有效控制提供有益借鉴。

How to effectively control the transient heat load caused by large-amplitude edge localized modes (ELMs) is an urgent problem in magnetic confinement fusion. A no-ELM H-mode operation regime has recently been observed with divertor impurity seeding in the EAST tokamak, providing a new approach to effectively control the heat load on the divertor target plate. However, the physical mechanism behind this regime is still unclear. In this project, all the experiments will be conducted in the EAST tokamak and the operational parameter space of this regime will be clarified. The relations between the behavior of type-I ELMs and the main plasma parameters with divertor impurity seeding will be obtained. By using the edge diagnostics with high spatial and temporal resolution, this project research will study the evolution characteristics of pedestal structure and fluctuations during the divertor impurity seeding process and further understand the physical mechanism behind the pedestal structure and suppression of type-I ELMs combined with numerical simulation codes. The reason why the plasma confinement performance is maintained during the divertor impurity seeding process will be ascertained. These studies can enhance our understanding on pedestal physics with divertor impurity seeding and provide a useful reference for effective control of ELMs in radiative divertor plasma with high confinement performance in EAST and future fusion reactors, such as CFETR.