Divertor conceptual designs for a fusion power plant

Developing a divertor concept for fusion power plants to be built after ITER is deemed to be an urgent task to meet the EU Fast Track scenario. This task is particularly challenging because of the wide range of requirements to be met, namely, the high incident peak heat flux, the blanket design with which the divertor has to be integrated, sputtering erosion of the plasma-facing material caused by the incident particles from the plasma, radiation effects on the properties of structural materials, and efficient recovery and conversion of the considerable fraction (∼15%) of the total fusion thermal power incident on the divertor.This paper provides an overview of the development of different conceptual divertor designs (water-cooled, liquid metal-cooled, and helium-cooled types); their advantages and disadvantages and expected performance are outlined and discussed. Emphasis is placed on summarizing the status and progress of R&D associated with He-cooled divertor designs which have been proposed in most of conceptual plant models in Europe and USA.