Analysis of heat transfer and erosion effects on ITER divertor plasma facing components induced by slow high-power transients

This paper presents the results of an analysis carried out to investigate the thermal response of ITER divertor plasma facing components (PFCs) clad with Be, W, and CFC, to high-recycling, high-power thermal transients (i.e. 10-30 MW/m²) which are anticipated to last up to a few seconds. The armour erosion and surface melting are estimated for the different plasma facing materials (PFMs) together with the maximum heat flux to the coolant, and armour/heat-sink interface temperature. The analysis assumes that intense target evaporation will lead to high radiative power losses in the plasma in front of the target which `self-protects´ the target. The cases analysed clarify the influence of several key parameters such as the plasma heat flux to the target, the loss of the melt layer, the duration of the event, the thickness of the armour, and comparison is made with cases without vapour shielding. Finally, some implications for the performance and lifetime of divertor PFCs clad with different PFMs are discussed