Power exhaust scenarios for EU-DEMO

We present an analysis of possible power exhaust scenarios for EU-DEMO. We employ the SOLPS-ITER code with the newly developed advanced fluid neutral model to scan a relatively wide range of neutral pressure divertor and impurity concentration in the core to test the existence of a suitable finite-extension operational space. Ideally, such a region should provide low target power fluxes, negligible erosion, high He divertor compression, and low impurity core concentration. Within the approximations of our model, we identified a non empty region where this long set of constraints can be satisfied. Here we use the constraints q max ⩽ 10 MWm − 2 , Z eff ⩽ 1.2 and T e ⩽ 5 eV, the latter being a proxy for detachment. This region corresponds to an upstream density within the range n e , up = 0.5 − 0.7 n e , GW (large but not necessarily prohibitive), Ar separatrix concentration ⩽ 10 − 3 and divertor neutral pressure ranging from 40 to 50 Pa. This is encouraging, in view of a more detailed analysis to be performed on the best-performance area.