边界局域模条件下托卡马克偏滤器靶板附近等离子体输运的数值研究

Based on the transient enhanced energy deposition of plasma facing component and particle sputtering during edge localized modes (ELMs), understanding plasma transport near the divertor plate in a tokamak has been of significance for the extension of materials lifetime and improvement of core plasma confinement. In this projection, the package SOLPS coupling the multi-fluid plasma model with the Monte-Carlo neutral model is used to investigate the divertor energy depositon and heat flux pofiles during ELMs in different magnetic topologies including single-null, double-null and connected double-null. The properties of plasma sheath containing energetic particles is also examined by the plasma particle-in-cell(PIC) software VORPAL. The boundaries conditions of the divertor plates for the plasma transport models are modified by ions velocity entering the sheath and sheath power transmission coefficients during ELMs modeling, and they are applied to SOLPS code.Then, the spatial characteristics of the divertor energy deposition and heat flux profiles are predicted by SOLPS code during ELMs for the high power input in EAST. The simulation results provide references for the optimized divertor designs for ITER and divertor designs for next reactor.

边界局域模爆发的时候会引起器壁材料的热负载和粒子溅射瞬时增强，研究边界局域模条件下托卡马克偏滤器靶板附近等离子体的输运对延长器壁材料寿命和提高主约束区等离子体性能有着重要意义。该项目拟用等离子体流体模型与中性粒子Monte-Carlo相耦合的大型边界输运程序包SOLPS为主要工具，研究在不同磁场拓扑结构（单零、双零、近双零）下，边界局域模爆发时偏滤器靶板的能量沉积和能流分布。同时利用等离子体粒子模拟软件VORPAL，研究包含高能量粒子的鞘层结构，分析离子进入鞘层的速度和鞘层的能量穿透系数，修正边界局域模条件下边界输运模型在偏滤器靶板处所采用的边界条件并应用到SOLPS程序中。然后使用SOLPS程序预测高功率加热下EAST装置爆发边界局域模时偏滤器靶板的能量沉积和能流分布的空间特性，为ITER长脉冲放电偏滤器优化和今后反应堆的偏滤器设计提供参考。

边界局域模爆发的时候会引起器壁材料的热负载和粒子溅射瞬时增强，研究边界局域模条件下托卡马克偏滤器靶板附近等离子体对延长器壁材料寿命和提高主约束区等离子体性能有着重要意义。本项目数值模拟边界局域模爆发时偏滤器靶板的能流分布，比较了EAST上单零和下单零情况下的偏滤器靶板能流随时间演化。分析包含高能量粒子的鞘层结构，得到离子进入鞘层的速度和鞘层的能量穿透系数，讨论了二次电子发射对鞘层结构以及鞘层能量穿透系数的影响，修正存在高能粒子情况下边界流体输运程序模型在偏滤器靶板处所采用的边界条件。同时研究了高能电子改变鞘层结构后对材料表面温度，伏安曲线，杂质溅射等的影响。 此外还预测高功率加热下EAST装置爆发边界局域模时的等离子体与材料相互作用过程，揭示材料表面温度的演化规律以及钨材料的物理溅射,为EAST长脉冲放电偏滤器优化和今后反应堆的偏滤器设计提供参考。受项目资助，在《Plasma Phys. Controlled Fusion》，《Phys. Plasmas》等杂志上共发表SCI收录论文十三篇，其中项目负责人作为第一作者八篇。