He离子辐照金属钨引入缺陷的微结构研究
Study on Microstructure of He+-irradiation Induced Defects in Tungsten

采用能量为100keV的He离子在室温下辐照金属钨，辐照注量范围为1.4×1017-3.5×1017/cm2，辐照后对样品进行了1100℃退火处理。利用X射线衍射、慢正电子多普勒展宽和扫描电镜技术研究了钨中He离子辐照引入的缺陷和注量之间的关系。研究结果表明辐照并退火后材料内部晶面间距增大,空位型缺陷浓度或尺寸随辐照注量的升高而增大，而高注量辐照的样品表面晶粒间连接疏松并存在孔隙，钨表层可能生成了大尺寸的He空位复合体或He泡。
The samples of tungsten were irradiated by 100keV helium ions at room temperature with different fluences ranging from 1.4×1017-3.5×1017/cm2 and then annealed at 1100℃. The interaction of helium-related defects with helium fluence was studied by means of X-ray diffraction (XRD), slow positron beam analysis (SPBA) and scanning electron microscope (SEM). The results show that the distance of crystal plane in tungsten increase after implantation. The concentration or/and size of the formed open-volume defects increase with the increase of irradiation fluence. The intergranular loose connections and voids on the surface of the sample, which were irradiated by the highest fluence of ions, reveal that there are vacancy-helium complexes or He bubbles with big size in the sample