We investigated the effect of edge-localized mode like transient heat events on pristine samples for two different grades of deformed tungsten with ultrafine and nanocrystalline grains as potential candidates for plasma-facing components. Pulses from a laser beam with durations ∼1 ms and operating in the near infrared wavelength were used for simulating transient heat loading in fusion devices. We specifically focused on investigating and analysis of different mechanisms for material removal from the sample surface under repetitive transient heat loads. Several techniques were applied for analysing different mechanisms leading to material removal from the W surface under repetitive transient heat loads which include witness plates for collected ejected material, and subsequent analysis using x-ray photoelectron spectroscopy and scanning electron microscopy, visible imaging using fast-gated camera, and evaluating thermal emission from the particles using optical emission spectroscopy. Our results show a significantly improved performance of polycrystalline cold-rolled tungsten compared to tungsten produced using an orthogonal machining process under repetitive transient loads for a wide range of the power densities.
我研究了边缘局域模类似瞬态热事件对两种不同变形钨（具有超细晶粒和纳米晶粒）作为等离子体 facing 组件潜在候选材料原始样品的影响。使用持续时间约1毫秒、工作在近红外波段的激光束脉冲来模拟聚变装置中的瞬态热加载。我们重点研究了重复瞬态热载荷下材料从样品表面去除的不同机制。采用多种技术分析了重复瞬态热载荷下钨表面材料去除的机制，包括使用 witness 片收集喷射材料，随后利用 X 射线光电子能谱和扫描电子显微镜进行分析，使用快照相机进行可见光成像，以及利用光学发射光谱评估颗粒的热辐射。我们的结果表明，在较宽的功率密度范围内，重复瞬态载荷下多晶冷轧钨的性能显著优于采用正交加工工艺制备的钨。