Abstract A tungsten (W) divertor is exposed to pulsed high heat caused by disruptions and Type-I Edge Localized Modes (ELMs). Therefore, it is important to investigate surface morphology of W during phase change. Heretofore, W melting dynamics under disruption-like heat load has been researched and tried to modify the optical system of our apparatus for knowing more detailed surface behavior. In this paper, the two measurement methods are shown; the in-situ observation of the W surface modification by a High Speed Video (HSV) camera and 3-Dimensional (3D) measurement of melting W surface by stereoscopic photography technique (SPT). In the former, the detailed process of W melting was clarified by observing W surface modification and analyzing luminance at the center of laser-irradiated spot. It was confirmed that luminescence at the center area of heat load fluctuated violently due to the phase change of W. In the latter, 3D images of W surface shape during melting was obtained using SPT and the results indicated that the W surface fluctuated in melting and gathered to the center gradually in solidifying. The calibration accuracy was still scope for improvement but the 3D measurement of W surface behavior loaded by high heat flux was established successfully.

中文翻译：

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原位测量暴露于脉冲高热通量的钨表面改性，用于托卡马克型聚变核反应堆偏滤器设计

摘要 钨 (W) 偏滤器暴露在由中断和 I 型边缘局部模式 (ELM) 引起的脉冲高温下。因此，研究相变过程中 W 的表面形貌很重要。迄今为止，已经研究了类似破坏的热负荷下的 W 熔化动力学，并试图修改我们设备的光学系统，以了解更详细的表面行为。在本文中，显示了两种测量方法；通过高速视频 (HSV) 相机原位观察 W 表面改性，并通过立体摄影技术 (SPT) 对熔化的 W 表面进行 3 维 (3D) 测量。在前者中，通过观察 W 表面改性和分析激光照射点中心的亮度来阐明 W 熔化的详细过程。经证实，由于 W 的相变，热负荷中心区域的发光剧烈波动。 在后者中，使用 SPT 获得 W 表面形状的 3D 图像熔化过程中，结果表明 W 表面在熔化和在凝固中逐渐向中心聚集。校准精度仍有改进的余地，但成功建立了高热通量加载的 W 表面行为的 3D 测量。