目前，我国正在大力发展X射线自由电子激光，如何评估薄膜光学元件在极紫外-X射线不同工作能段的抗损伤性能、探索研究具有更大全反射角和抗损伤能力的新型反射式薄膜光学元件是亟需解决的科学问题。针对这些问题，本项目拟用自行搭建的极紫外辐照损伤装置以及上海软X射线自由电子激光开展损伤研究，分析低Z、高Z原子序数和低Z/高Z双层膜材料辐照损伤与波长和角度等因素的关联性，结合有限元等方法分析薄膜元件的损伤机理和抗损伤能力。通过实验与理论相结合，建立一套极紫外-X射线波段薄膜元件抗损伤性能评估方法，为我国硬X射线自由电子激光光束线用薄膜光学元件的设计和抗损伤性能评估发挥作用。

Presently, China is rapidly developing X-ray free electron laser (XFEL). There are some important scientific questions needed to be answered, which includes how to evaluate the damage-resistance capability of thin-film optics in different energy regions and to develop new-type reflective thin-film optics with good damage-resistance capabilities and relatively large critical angles. For answering these questions, based on the EUV damage instrument built in our laboratory and Shanghai soft X-ray FEL light source, this project is planned to do damage experiments on low Z, high Z and low Z/high Z bilayer materials as a function of the wavelength and incidence angles, etc. The damage mechanisms and the damage-resistance capabilities are hoped to be figured out by comparing the experimental results with the analysis of finite element method. By combining the experimental and theoretical analysis together, an evaluation method will be developed on evaluating the damage-resistance capabilities for different types of thin-film optics in the energy region from EUV to X-ray. It is hoped to make some contributions for designing the structures and evaluating the damage-resistance properties of thin-film optics used in the beamlines of hard X-ray free electron laser facility in China.