EAST钨瓦块棱角热负荷性能改善的计算模拟研究

W/Cu monoblock is used for EAST and ITER divertor targets to remove heat load effectively on the Plasma Facing Components (PFCs). However, power handling capability may be degraded significantly due to hot spots at the leading edges introduced by castellation. Moreover, the melting tungsten droplets can penetrate into the core plasma causing its radiative cooling. To meet the urgent need of upgrading EAST PFCs into full tungsten tiles, this project is dedicated to understand the plasma basis of leading edge problems and reveal the relation between parallel power load and different misalignments of leading edge in EAST normal and reversed fields by a series of simulation methods, such as particle in cell method and heat flux calculation. On the basis of prediction the power load and temperature on PFCs precisely, optimization of the castellation structure will be implemented to improve the power handling capability. The work will not only contribute to the stable operation of high performance long pulse plasmas on EAST by achieving good wall conditions, but also provide significant experience for ITER.

为了及时有效地移除沉积在面向等离子体部件（PFCs）上的热负荷，钨铜穿管部件（Monoblock）将用于EAST和ITER的偏滤器垂直靶板区域。然而穿管结构缝隙边缘正对磁力线部位形成突出棱角（leading edge），承受极大的平行热流，导致局部过热甚至熔化，进而降低钨瓦的热负荷性能，减少寿命；另外熔化的液滴进入芯部，因辐射冷却而可能熄灭等离子体。针对EAST装置全钨壁计划的紧迫需求，本项目拟使用粒子模拟和热流模拟等一系列方法理解粒子流、热流和leading edge的物理作用机制，掌握EAST正反场运行模式下leading edge承载热负荷的规律，进而基于对瓦块边缘棱角热流和温度分布的准确评估，优化瓦块结构的设计，改善leading edge的热负荷性能。为EAST的高参数长脉冲稳定运行提供良好的壁条件，同时也为国际热核实验堆ITER提供有价值的参考。

为了及时有效地移除沉积在面向等离子体部件（PFCs）上的热负荷，钨铜穿管部件（Monoblock）将用于EAST和ITER的偏滤器垂直靶板区域。然而穿管结构缝隙边缘正对磁力线部位形成突出棱角（leading edge），承受极大的平行热流，导致局部过热甚至熔化，进而降低钨瓦的热负荷性能，减少寿命；另外熔化的液滴进入芯部，因辐射冷却而可能熄灭等离子体。针对EAST装置全钨壁计划的紧迫需求，本项目使用PFCFlux程序和粒子模拟PICS2程序得到EAST规则和不规则钨瓦块热流分布规律，结合有限元分析对瓦块边缘棱角温度分布准确评估，在此基础上，对瓦块进行优化设计，并将优化的瓦块用于EAST装置中进行实验验证，为EAST的高参数长脉冲稳定运行提供良好的壁条件，同时也为国际热核实验堆ITER提供有价值的参考。