Abstract

The effect of the formation of numerous pits on the surface of polished polycrystalline and single-crystal Mo mirrors after their successive irradiation with He and Ar ions in a gas discharge is found. The pits have the shape of round holes and long multidirectional linear grooves, the maximum depth of which is equal to the thickness of the layer damaged during polishing. The shape of the linear grooves corresponds to scratches immured at different stages of polishing, while their width and depth are determined presumably by the typical size of the used abrasive grains (~1 µm). The overwhelming majority of pits are formed at the interface between the damaged layer and the slightly deformed substrate material, where the gas-diffusion rate sharply decreases. The pitting effect leads to sharp degradation of the optical characteristics of the mirrors. The results obtained can be used to improve the polishing technology and to develop mirror cleaning systems for optical diagnostics of the plasma of thermonuclear facilities.

中文翻译：

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用氦和氩离子连续照射钼镜期间的离子刺激点蚀

摘要

发现了在气体放电中连续照射 He 和 Ar 离子后，在抛光的多晶和单晶 Mo 镜表面上形成大量凹坑的影响。凹坑的形状为圆孔和长长的多向线性凹槽，其最大深度等于抛光过程中损坏的层的厚度。线性凹槽的形状对应于在不同抛光阶段留下的划痕，而它们的宽度和深度大概由所用磨粒的典型尺寸 (~1 µm) 决定。绝大多数凹坑形成在损伤层和轻微变形的基板材料之间的界面处，气体扩散速率急剧下降。点蚀效应导致反射镜光学特性急剧下降。