氩等离子体与预辐照钨基Li-CPS结构相互作用研究

Study on the interaction between argon plasma and pre-irradiated tungsten Li-CPS structure

本文利用四川大学直线等离子体发生装置(SCU-PSI)研究了不同入射能量的氦(He)等离子体对钨筛网的辐照行为以及氩(Ar)等离子体与预辐照液态锂(Li)钨基多孔筛网结构(CPS)的相互作用.实验结果表明,在不同入射能量的He等离子体辐照后,钨筛网表面形貌出现明显的辐照损伤,并且随着入射能量增加,钨筛网初始平整的表面形貌逐渐变为纳米针孔结构,最终转变为纳米绒毛结构.用相同He等离子体参数辐照钨块材,发现钨筛网产生辐照损伤的阈值显著低于钨块材.利用Ar等离子体对预辐照的钨基Li-CPS结构进行辐照实验.结果显示,预辐照Li-CPS靶板Li液面非常不稳定,在表面形成Li液滴并喷射到等离子体内部.而且靶板表面温度异常升高,比不存在辐照损伤的钨基Li-CPS结构高400℃左右.之后对Ar等离子体辐照后的预辐照Li-CPS结构的表面形貌进行SEM分析,发现由于比表面积增加,使得钨筛网表面绒毛结构被液态Li腐蚀.

In this paper,the irradiation behavior of helium plasma with different incident energies on tungsten meshes and the interaction between argon plasma and pre-irradiated liquid lithium(Li)tungsten-based capillary porous structure(CPS)were investigated by using the linear plasma generator at Sichuan University(SCU-PSI).The experimental results show that the surface morphology of the tungsten meshes is obviously damaged under He plasma irradiation with different incident energies.As the incident energy of He plasma is increased,the formed patterns gradually change into nano-pinhole structure,and finally into nano-fuzz structure.When tungsten block was irradiated with the same He plasma parameters,it was found that the threshold of irradiation damage of the tungsten mesh is significantly lower than that of the tungsten bulk.Irradiation experiments were performed on pre-irradiated tungsten-based Li-CPS using argon plasma.The results show that the Li surface of the pre-irradiated Li-CPS target plate is very unstable,forming Li droplets on the surface and ejecting into the plasma interior.Moreover,the surface temperature of the target plate is abnormally high,about 400℃higher than that of the tungsten-based Li-CPS structure without irradiation damage.The SEM analysis of the surface morphology of the pre-irradiated Li-CPS structure after argon plasma irradiation later indicates that the increase of specific surface area of the fuzz structure accelerated the corrosion of the tungsten mesh surface in liquid Li.