Characterisation of a monoblock-type plasma-facing component before and after HHF fatigue loading, by means of neutron imaging techniques

In magnetic confinement fusion reactor devices, the edge plasma and surrounding material surfaces provide a buffer zone between high-temperature conditions in the plasma core and the normal terrestrial environment. The plasma-facing components (PFCs) that line the vacuum vessel of a tokamak are subjected to the most hostile conditions of all the materials in the fusion reactor. The PFC used in the divertor region is based on the monoblock construction. For ITER reactor, the peak surface heat flux is expected to reach up to 10 MWm-2 during normal operation and 20MWm-2 during low transient events. Therefore, it is vital that the PFCs employed in the divertor must maintain structural integrity under high-heat-flux (HHF). Thus, we propose to study a single tungsten monoblock-type plasma-facing component, before (as manufactured) and after HHF fatigue load.