中文摘要：

用磁控溅射技术制备不同调幅波长（L）的W（Mo）/Cu纳米多层膜,所制膜系在60keV氦离子（He^＋）辐照条件下注入不同剂量：0,1×10^17He^＋/cm^2,5×1017He^＋/cm^2.用X射线衍射仪（XRD）和高分辨透射电子显微镜（TEM）表征W（Mo）/Cu纳米多层膜辐照前后微观结构.研究结果表明：1）He^＋离子轰击引起温升效应是导致沉积态亚稳相β-W转变成稳态α-W相的主因,而与调幅波长无明确关联;2）纳米多层结构中W（Mo）和Cu膜显现出的辐照耐受性与调幅波长相关,调幅波长越小,抗He^＋的辐照性能越强;3）在5×10^17He^＋/cm^2注入条件下,观察到He团簇/泡在纳米结构W（Mo）和Cu膜中的积聚行为存在明显差异：在W（Mo）膜中He团簇/泡的分布与晶粒取向相关,He团簇/泡倾向于沿W（211）晶面分布;而Cu膜非晶化且He团簇/泡在其体内呈均匀分布.

英文摘要：

W（Mo, 9.8 at.%）/Cu nanometer multilayer films of different individual layer thickness were prepared by RF magnetron sputtering, which were irradiated by 60 keV He ＋ ions at ion fluence from 0 to 5 × 10^17 He^＋/cm^2. Microstructures of nanometer multilayer W（Mo）/Cu films were investigated by high-resolution transmission electron microscope （HRTEM） and X-ray diffraction （XRD） before and after irradiation. Experimental results indicate that： （1） The phase transformation of β-W （A-15） into steady state α-W can be attributed to the bombardment effect of energetic He ions on the surface of films, leading to phase-transition temperature during irradiation. （2） The irradiation tolerance of W（Mo）/Cu multilayer film was found to depend on the individual layer thickness. （3） At the fluence of 5 × 10^17 He^＋/cm^2, the HRTEM results reveal that the behavior of helium cluster/bubble in the W（Mo） film is obviously different from that in the Cu film. It is interesting that the distribution of helium cluster/bubble is related to the grain orientation of W（Mo） film and tends to distribute along W （211） plane. However, Cu film is completely amorphized and helium cluster/bubble is evenly distributed in it.