Prospects for Steady-State Scenarios on JET
In the 2006 experimental campaign, progress has been made to operate non-inductive scenarios at higher applied powers (27MW) and density (nl~4¥1019m-3 ), with ITER-relevant safety factor (q95~5) and plasma shaping, taking advantage of the new divertor capabilities. The extrapolation of the performance using transport modelling benchmarked on the experimental database indicates that the foreseen power upgrade (~45MW) will allow the development of non-inductive scenarios where the bootstrap current is maximised together with the fusion yield and not, as in present day experiments, at its expense. The tools for the long-term JET programme are the new ITER-like ICRH antenna (~15MW), an upgrade of the NB power (35MW/20s or 17.5MW/40s), a new ITER-like first wall, a new pellet injector for ELM control together with improved diagnostic and control capability. Operation with the new wall will set new constraints on non-inductive scenarios that are already addressed experimentally and in the modelling. The fusion performance and driven current that could be reached at high density and power have been estimated using either 0-Dimensional or 1-1/2D validated transport models. In the high power case (45MW), the calculations indicate the potential for the operational space of the non-inductive regime to be extended in terms of current (~2.5MA) and density (nl~5¥1019m-3 ), with high bN (bN>3.0) and a fraction of the bootstrap current within 60-70% at high toroidal field (~3.5T).