Liptak Alexander, Lawson Kerry D, Hasan Mohammad I
Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK.
Sci Rep. 2025 Apr 29;15(1):15068. doi: 10.1038/s41598-025-98065-1.
The plasma-facing components of nuclear fusion reactors are continuously subjected to high thermal loads and bombardment by hydrogenic ions, resulting in erosion of the first-wall material and sputtering of atomic and molecular species into the edge plasma. The management of reactor component lifetimes and control of sputtered plasma impurities remain open problems in fusion research, where quantifying the sputtering yields and understanding the sputtering processes of each impurity species is pivotal for planning an effective maintenance schedule and ensuring optimal plasma performance. Although the sputtering of atomic species is historically well-established, the sputtering of molecules from metallic first-wall materials such as beryllium has only recently been confirmed possible and relevant for fusion reactors. In this study, a molecular dynamics model is used to investigate the sputtering of atomic beryllium, Be dimers, Be trimers, beryllium hydrides, and hydrogenic dimers. The sputtering yield of each species is reported, and the observed ion trajectory preferential sputtering behaviour is presented; beryllium lattice thermal effects as well as bombarding ion isotope effects are discussed where relevant. A theoretical description of the universal sputtering yield relation and its various corrections are explored in detail, and the molecular dynamics model is benchmarked against analytical, computational and experimental data.
核聚变反应堆中面向等离子体的部件持续承受高热负荷以及氢离子的轰击，导致第一壁材料受到侵蚀，原子和分子种类溅射到边缘等离子体中。反应堆部件寿命的管理以及溅射等离子体杂质的控制在聚变研究中仍然是未解决的问题，其中量化溅射产率并了解每种杂质种类的溅射过程对于制定有效的维护计划和确保最佳等离子体性能至关重要。尽管原子种类的溅射在历史上已得到充分证实，但从诸如铍等金属第一壁材料中溅射分子直到最近才被证实是可能的且与聚变反应堆相关。在本研究中，使用分子动力学模型来研究原子铍、铍二聚体、铍三聚体、氢化铍和氢二聚体的溅射。报告了每种物质的溅射产率，并展示了观察到的离子轨迹优先溅射行为；在相关情况下讨论了铍晶格热效应以及轰击离子同位素效应。详细探讨了通用溅射产率关系及其各种修正的理论描述，并将分子动力学模型与分析、计算和实验数据进行了基准测试。
