Influence of H+ ion irradiation on the surface and microstructural changes of a nuclear graphite

Despite the significant importance of nuclear graphite as a promising plasma-facing component material in all thermonuclear fusion devices, its physico-chemical microstructural behavior under severe irradiation conditions was poorly understood. To provide a wide range of information and understanding about the structure change of nuclear graphite under energetic hydrogen ion irradiation, we therefore carried out a systematic study with employing various characterization tools such as scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), and X-ray photoemission spectroscopy (XPS). Furthermore, we suggested possible surface chemical erosion mechanism from the observed physico-chemical microstructural changes.

► Nuclear graphites as a class of promising materials for the plasma-facing component (PFC) of thermonuclear fusion devices. ► Effects of the ion-irradiation on the physico-chemical microstructural changes of nuclear graphite. ► Surface chemical erosion mechanism from the observed physico-chemical microstructural changes.