Tungsten Erosion by the Initiation of Unipolar Arcs in Nuclear Fusion Devices

摘要

Arcing is a long standing plasma-surface interaction issue in nuclear fusion research. In this study, erosion of nanostructured tungsten surface due to arcing was estimated by analyzing the arc trail in detail. The sample with arc trail was fabricated with focused ion beam milling process and observed by transmission electron microscope. It was found that more than half of the tungsten still remained after an arc spot runs on the nanostructure. This is the first report on the erosion rate of tungsten, which is essential for fusion devices, by the initiation of arcing.