Status and physics basis of the ITER divertor

The ITER divertor design is the culmination of years of physics and engineering effort, building confidence that this critical component will satisfy the requirements and meet the challenge of burning plasma operation. With 54 cassette assemblies, each weighing ∼9 tonnes, nearly 3900 actively cooled high heat flux elements rated to steady-state surface power flux densities of 10 MW m−2 and a total of ∼60 000 carbon fibre composite monoblocks and ∼260 000 tungsten monoblocks/flat tiles, the ITER divertor will be the largest and most advanced of its kind ever constructed. Both the ITER Design Review and subsequent follow-up activities have led to a number of modifications to the device, including the divertor design, significantly improving ITER's operational flexibility. This paper outlines the salient features of the final divertor design, with emphasis on the physics rationale that has defined the design choices and on the performance of the resulting configuration.