Mechanism of single-shot damage of Ru thin films irradiated by femtosecond extreme UV free-electron laser
Mechanism of single-shot damage of Ru thin films irradiated by femtosecond extreme UV free-electron laser
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DOI：
10.1364/oe.26.019665
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发表时间：
2018-07-23
期刊：
影响因子：
3.8
通讯作者：
Bijkerk, Fred
中科院分区：
文献类型：
--
作者：
Milov, Igor;Makhotkin, Igor A.;Bijkerk, Fred
钌是自由电子激光装置中用于XUV反射镜的一种有前景的材料。然而，在超快激光-物质相互作用的背景下，它仍然是很少的研究。在这项工作中，我们提出了单次射击损伤的研究薄Ru膜的飞秒XUV自由电子激光脉冲照射在FLASH。通过不同类型的显微镜对受损点进行的非原位分析表明，检测到的最弱损伤是表面粗糙化。对于更高的注量，我们观察到Ru的烧蚀。结合蒙特-卡罗程序XCASCADE（3D）和双温模型的模拟结果表明，激光辐照靶板的损伤机制与激光辐照靶板的损伤机制相似，属于光机械损伤。与光学损伤研究的类比，使我们能够解释所观察到的损伤形态。(C)根据OSA开放获取出版协议的条款，2018年美国光学学会
Ruthenium is a perspective material to be used for XUV mirrors at free-electron laser facilities. Yet, it is still poorly studied in the context of ultrafast laser-matter interaction. In this work, we present single-shot damage studies of thin Ru films irradiated by femtosecond XUV free-electron laser pulses at FLASH. Ex-situ analysis of the damaged spots, performed by different types of microscopy, shows that the weakest detected damage is surface roughening. For higher fluences we observe ablation of Ru. Combined simulations using Monte-Carlo code XCASCADE(3D) and the two-temperature model reveal that the damage mechanism is photomechanical spallation, similar to the case of irradiating the target with optical lasers. The analogy with the optical damage studies enables us to explain the observed damage morphologies. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement