Erosion characteristics of neutron-irradiated carbon-based materials under simulated disruption heat loads

This paper presents disruption simulation experiments on neutron-irradiated carbon-based materials to investigate the erosion characteristics of irradiated materials. Uni-directional (1D) and 2D carbon fiber reinforced carbon composites (CFCs), which are one of the promising materials for the plasma facing components of the fusion experimental reactors, were selected as a test material. These samples were irradiated by neutrons with a total neutron fluence of 3.2–5.6×1024 n/m2, which corresponds to 0.3–0.5 dpa, at an irradiation temperature of 280–320°C. After the neutron irradiation, disruption simulation experiments were carried out at the electron beam facility in the hot-cell under a heat load of 20 MJ/m2, which simulates the ITER disruption conditions. As a result, the weight losses of neutron-irradiated 1D and 2D CFCs increase as the neutron fluence increases. The maximum erosion depth does not change with the neutron fluence. The surface erosion profile is much broader with increasing neutron fluence. It can be seen that the increase in weight loss was caused by the broadened erosion profile.