DEMO exhaust challenges beyond ITER

In the European fusion road-map, ITER is followed by a demonstration fusion reactor (DEMO) [1]. Table 1 lists parameters of several recent EU DEMO designs. The designs are tokamaks in H-mode operation with a closed fuel cycle. In comparison to the ITER (Q = 10) design the European DEMO design options have significantly fusion power, bN, higher temperature across the whole profile, higher fueling rate and higher core radiation fraction. Also various engineering boundary conditions are significantly more restrictive than for ITER. Due to this there is a number of areas, in which the physics challenges of DEMO - mostly related to the feasibility or the cost of the device - go considerably beyond the ones for ITER. This paper addresses the important subset of these additional challenges, which concentrate around the topic of power and particle exhaust.