Simulations of lithium (Li) impurity transport behaviour with a liquid lithium divertor on the EAST tokamak have been performed using the fluid code EMC3-EIRENE and the Monte Carlo code ITCD. The interactions between particles and the wall surface, like the gyration-induced scrape-off effect, sheath acceleration, kinetic self-sputtering and reflection, are typically ignored or simplified in fluid models. In order to uncover the impacts of the scrape-off effect, sheath acceleration, kinetic self-sputtering and reflection on Li distribution, detailed analysis of the density distributions of Li1+ and Li2+ ions at the divertor region have been carried out by ITCD modelling. The newly-upgraded ITCD code can principally reproduce the distribution patterns of Li ions as well as EMC3-EIRENE under identical plasma conditions on EAST. However, due to the scrape-off effect and sheath acceleration, the densities of Li1+ and Li2+ ions simulated by ITCD are evidently reduced compared to the EMC3-EIRENE simulations. The kinetic self-sputtering by redeposited Li particles in ITCD can increase the densities of the Li ions. Moreover, the kinetic reflection database calculated by SRIM code has been employed by ITCD, which leads to an increase in the Li densities compared to the reflection approach used in EMC3-EIRENE. Overall, by adding the aforesaid physical effects in ITCD, the total number of Li ions shows an obvious reduction compared to the EMC3-EIRENE modelling.
在EAST托卡马克装置上，利用流体代码EMC3-EIRENE和蒙特卡洛代码ITCD，对液态锂偏滤器下的锂杂质输运行为进行了模拟研究。在流体模型中，粒子与壁面之间的相互作用，如回旋刮削效应、鞘层加速、动力学自溅射及反射等，通常被忽略或简化处理。为揭示这些效应对锂分布的影响，本研究通过ITCD模拟，对偏滤器区域Li1+和Li2+离子的密度分布进行了详细分析。结果表明，新升级的ITCD代码在相同等离子体条件下，能够基本重现EMC3-EIRENE所预测的锂离子分布模式。然而，由于刮削效应和鞘层加速的作用，ITCD模拟得到的Li1+和Li2+离子密度明显低于EMC3-EIRENE的结果。此外，ITCD中考虑了再沉积锂粒子的动力学自溅射效应，这会导致锂离子密度增加。同时，采用基于SRIM计算得到的动力学反射数据库，相较于EMC3-EIRENE中使用的简化反射模型，也使得锂密度有所上升。总体而言，在ITCD中纳入上述物理效应后，锂离子总数相较于EMC3-EIRENE模拟结果呈现出显著减少。