Spatial Resolution Measurements of C, Si and Mo Using LIBS for Diagnostics of Plasma Facing Materials in a Fusion Device
Spatial Resolution Measurements of C, Si and Mo Using LIBS for Diagnostics of Plasma Facing Materials in a Fusion Device
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DOI：
10.1088/1009-0630/17/8/05
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发表时间：
2015-03
影响因子：
1.7
通讯作者：
Cong Li;Dongye Zhao;Xingwei Wu;H. Ding
中科院分区：
文献类型：
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作者：
Cong Li;Dongye Zhao;Xingwei Wu;H. Ding
最近，开发了一种激光诱导击穿光谱（LIBS）系统，用于在实验先进超导托卡马克（EAST）中对等离子体表面材料（PFM）的化学成分进行原位测量。在本研究中，开发了一种 LIBS 系统，其光学配置与 EAST 中的原位 LIBS 系统类似，用于研究 10−4 Pa 下 PFM 元素的空间分布。本研究的目的是了解等离子体羽流中不同元素的原子或离子的空间分布性质，并优化 EAST 中原位 LIBS 诊断的信背景比。测量了 C、Si、Mo 和连续背景的 LIBS 信号的空间分布。此外，还研究了激光光斑尺寸和激光能量密度对C、Si、Mo和H的LIBS信号的影响。结果表明，从等离子体羽流中心到边缘，C、Si、Mo峰强度分布先增大后减小。距等离子体羽流中心 R 约 1.5 毫米处存在最大值。这项工作旨在提高对极低压环境中烧蚀等离子体动力学的理解，并为优化 EAST 装置中的 LIBS 系统提供指导。
Recently, a laser-induced breakdown spectroscopic (LIBS) system has been developed for in situ measurements of the chemical compositions of plasma facing materials (PFMs) in the Experimental Advanced Superconducting Tokamak (EAST). In this study, a LIBS system, which was used in a similar optical configuration to the in situ LIBS system in EAST, has been developed to investigate the spatial distribution of PFM elements at 10−4 Pa. The aim of this study was to understand the nature of the spatial distribution of atoms or ions of different elements in the plasma plume and optimize the signal to background ratio for the in situ LIBS diagnosis in EAST. The spatial profiles of the LIBS signals of C, Si, Mo and the continuous background were measured. Moreover, the influence of laser spot size and laser energy density on the LIBS signals of C, Si, Mo and H was also investigated. The results show that the distribution of the C, Si and Mo peaks' intensities first increased and then decreased from the center to the edge of the plasma plume. There was a maximum value at R ≈ 1.5 mm from the center of the plasma plume. This work aims to improve the understanding of ablating plasma dynamics in very low pressure environments and give guidance to optimize the LIBS system in the EAST device.