Impact of the JET ITER-Like Wall On the Current Ramp Up Phase and q-Profile Optimisation for Hybrid and Advanced Scenarios
The ITER-Like Wall (ILW) in JET is composed of Be main wall and W divertor. As reported in, it has changed the wall conditioning and recycling behaviour, modified the plasma impurity content, and impacted on the plasma initiation, leading to lower radiation and higher electron density (ne) at the end of the burn-through phase. This motivated experiments to assess the impact of the ILW on the plasma current (IP) diffusion during the IP rise, presented here. Also described is the work started to recover the q-profiles required for improved stability and confinement, i.e. with a broad region of weak magnetic shear in the plasma core with q0 1 for hybrid plasmas and 1 <qmin 2 for advanced scenarios.