低杂波产生的快电子对EAST偏滤器靶板热流及等离子体-壁相互作用的影响

稳态运行是国际热核聚变反应堆（ITER）和中国聚变工程实验堆（CFETR）所追求的主要运行模式之一，低杂波电流驱动由于驱动效率高的特点已成为ITER和CFETR实现稳态运行最具潜力的手段。如何控制稳态运行下偏滤器靶板上的热负载以及优化等离子体与靶板材料相互作用已成为当前磁约束聚变研究的焦点问题之一。近期EAST低杂波电流驱动实验结果表明，在低杂波天线附近存在快电子，这些快电子会沿着磁力线到达偏滤器靶板，影响偏滤器靶板热流。本项目将通过发展包括等离子体与壁材料相互作用的粒子模拟程序，研究低杂波产生的快电子对EAST偏滤器靶板热流及等离子体-壁相互作用的影响，弄清EAST边界快电子产生机制、快电子运动到偏滤器靶板期间在相空间的输运过程以及快电子对偏滤器靶板鞘层的影响，为EAST实验数据分析和物理解释提供支持。

The steady state operation is one of the most desired operation scenarios for ITER and CFETR. Lower hybrid current drive has become the most promising approach to achieve the steady state operation due to its high current drive efficiency. How to control the heat load on divertor target plates and optimize the plasma-wall interactions have drawn a lot attentions and have been intensively investigated in recent years. Recent lower hybrid experiments on EAST have shown that there exist fast electrons in the vicinity of lower hybrid antenna. The fast electrons can arrive at the divertor target as moving along the magnetic lines and significantly affect the heat flux to the divertor. It is thus proposed to study the effects of the fast electrons on EAST divertor heat fluxes and plasma-wall interactions by developing a particle-in-cell simulation code. The goals to be reached include understanding (1) how the fast electrons are produced on EAST, (2) transport of the fast electrons in the phase space when moving along the magnetic lines, (3) how the sheath formed on the target plate is affected by the fast electrons. The research will be beneficial to data analysis of EAST lower hybrid experiments and provide physical insights for experimental result interpretations.