Fuel retention measurement on plasma-facing components is an active field of study in magnetic confinement nuclear fusion devices. The laser-induced breakdown spectroscopy (LIBS) diagnostic method has been well demonstrated to detect the elemental distribution in PFCs. In this work, an upgraded co-axis LIBS system based on a linear fiber bundle collection system has been developed to measure the hydrogen (H) retention on a tantalum (Ta) sample under a vacuum condition. The spatial resolution measurement of the different positions of the LIBS plasma can be achieved simultaneously with varying delay times. The temporal and spatial evolution results of LIBS plasma emission show that the H plasma observably expands from the delay times of 0–200 ns. The diameter of Ta plasma is about 6 mm which is much less than the size of H plasma after 200 ns. The difference in the temporal and spatial evolution behaviors between H plasma and Ta plasma is due to the great difference in the atomic...

中文翻译：

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激光击穿光谱法在钽中氢保留的时空演变测量

面向等离子体组件的燃料保留量测量是磁约束核聚变设备研究的一个活跃领域。激光诱导击穿光谱法（LIBS）诊断方法已被证明可检测PFC中的元素分布。在这项工作中，已经开发出一种基于线性纤维束收集系统的升级的同轴LIBS系统，以在真空条件下测量钽（Ta）样品上的氢（H）保留量。LIBS等离子体不同位置的空间分辨率测量可以通过变化的延迟时间同时实现。LIBS等离子体发射的时空演化结果表明，H等离子体在0–200 ns的延迟时间内可观察到扩展。Ta等离子体的直径约为6 mm，远小于200 ns后的H等离子体的大小。