Lithium wall conditioning has improved the performance of many magnetic fusion devices. Li conditioning in the RFX-mod device was performed by: (1) a single Li pellet injector and (2) a multi-Li pellet injector during He plasma discharges; (3) a Li evaporator after He glow discharge cleaning and He plasma discharge exposure. This report compares the spatial and depth distributions of Li deposited on polycrystalline graphite witness samples at different locations in RFX-mod and the elemental and chemical compositions of the resulting surfaces. The sample surfaces were analyzed ex situ using secondary ion mass spectrometry (SIMS) and high-resolution X-ray photoelectron spectroscopy (HR-XPS). The results showed that Li pellet injection provided a relatively uniform toroidal coverage while Li evaporation produced highly localized Li deposition. A Li 1s HR-XPS peak at 56.5 eV binding energy (BE) characteristic of lithium-intercalated graphite was only observed with the sample exposed to Li evaporation. All of the samples exhibited a HR-XPS C 1s peak at 285.1-285.2 eV BE that is largely attributed to hydrogenated graphite. This finding suggests that hydrogenation of fresh graphite occurs during He plasma discharge exposures. Our results have implications for density control and the selection of Li conditioning techniques in magnetic fusion devices.

锂壁调节改善了许多磁聚变装置的性能。RFX-mod 装置中的锂调节通过以下方式进行：（1）单个锂颗粒喷射器和（2）He 等离子体放电期间的多锂颗粒喷射器；(3) He辉光放电清洗和He等离子体放电曝光后的Li蒸发器。本报告比较了 RFX-mod 中不同位置的多晶石墨见证样品上沉积的锂的空间和深度分布，以及所得表面的元素和化学成分。使用二次离子质谱 (SIMS) 和高分辨率 X 射线光电子能谱 (HR-XPS) 对样品表面进行异位分析。结果表明，锂颗粒注入提供了相对均匀的环形覆盖，而锂蒸发产生了高度局部的锂沉积。仅在暴露于锂蒸发的样品中观察到锂嵌入石墨在 56.5 eV 结合能 (BE) 特征处的 Li 1s HR-XPS 峰。所有样品都在 285.1-285.2 eV BE 处显示出 HR-XPS C 1s 峰，这主要归因于氢化石墨。这一发现表明新鲜石墨的氢化发生在 He 等离子体放电暴露期间。我们的结果对磁聚变装置中的密度控制和锂调节技术的选择具有影响。这一发现表明新鲜石墨的氢化发生在 He 等离子体放电暴露期间。我们的结果对磁聚变装置中的密度控制和锂调节技术的选择具有影响。这一发现表明新鲜石墨的氢化发生在 He 等离子体放电暴露期间。我们的结果对磁聚变装置中的密度控制和锂调节技术的选择具有影响。