On the Challenge of Plasma Heating with the JET Metallic Wall
In this paper, the major aspects linked to the use of the JET heating systems: NBI, ICRF and LHCD, in the new JET ITER-like wall (ILW) are presented. We show that although there were issues related to the operation of each system, efficient and safe plasma heating was obtained with room for higher power. For the NBI up to 25.7MW was safely injected; issues that had to be tackled were mainly the beam shine through and beam re-ionisation before entrance in the plasma. For the ICRF system, 5MW were coupled in L-mode and 4MW in H-mode; the main areas of concern were RF-sheaths related heat loads and impurities production. For the LH, 2.5MW were delivered without problems; arcing and generation of fast electron beams in front of the launcher that can lead to high heat loads were the keys issues. For each system, an overview will be given of: their compatibility with the new metallic wall, the main modifications implemented for a safe use, the differences in behavior compared with the previous wall in carbon, with special emphasis on heat loads and impurity content in the plasma.