Formation process of tungsten nanostructure by the exposure to helium plasma under fusion relevant plasma conditions
Formation process of tungsten nanostructure by the exposure to helium plasma under fusion relevant plasma conditions
复制标题
DOI：
10.1088/0029-5515/49/9/095005
复制
发表时间：
2009-09-01
期刊：
影响因子：
3.3
通讯作者：
Saeki, Tsubasa
中科院分区：
文献类型：
--
作者：
Kajita, Shin;Sakaguchi, Wataru;Saeki, Tsubasa
氦气照射钨会形成纳米尺寸的纤维结构，从而显着改变表面形态，这可能会给聚变反应堆带来严重的问题。从线性偏滤器模拟器的实验结果表明，入射离子能量和表面温度是结构形成的关键参数。结果表明，当温度在1000-2000 K范围内且入射离子能量高于20 eV时，容易形成钨纳米结构。此外，基于在偏滤器模拟器NAGDIS-I中进行的氦辐照实验，揭示了纳米结构的初始形成过程。结果表明，纳米结构的形成与材料大部分上出现的针孔有关，然后，粗糙的结构发展为更精细的纳米结构。在暴露于氦等离子体的钼表面上也观察到了纳米结构。它增加了人们对氦辐照形成纳米结构是各种金属上发生的常见现象的可能性的兴趣。
Helium irradiation on tungsten changes the surface morphology dramatically by forming a nanometre-sized fibreform structure which could bring about serious problems for fusion reactors. From the experimental results in liner divertor simulators, it is revealed that the incident ion energy and surface temperature are key parameters for the formation of the structure. It is shown that the tungsten nanostructure is easily formed when the temperature is in the range 1000-2000 K, and the incident ion energy is higher than 20 eV. Furthermore, on the basis of the helium irradiation experiments performed in the divertor simulator NAGDIS-I, the initial formation process of the nanostructure is revealed. It is shown that the nanostructure formation is related to pinholes appearing on the bulk part of the material, and then, the rough structure develops to a much finer nanostructure. The nanostructure was also observed on the molybdenum surface that was exposed to the helium plasma. It increases interest in the possibility that nanostructure formation by helium irradiation is a common phenomenon that occurs on various metals.