Optimization of the JET beryllium tile profile for power handling

The primary objective of the JET ITER-like wall project is to install a beryllium main wall and a tungsten divertor. For beryllium, melting and thermal stress limit the maximum power density which can be tolerated in operation. The tile design has to allow routine plasma operation for ITER relevant scenarios, i.e., q95 f ≈ [2.3–10] with high power input (Pin ≤ 30 MW) for pulse lengths of ≈10 s. This paper focuses on the power handling studies of the beryllium tiles for the outer poloidal limiters and ICRH horizontal protections, and the optimization of their design to achieve the operational goal described above.