PROFILE CONTROL FOR STEADY-STATE OPERATION

Large departures from standard L-mode confinement scaling laws are now being observed in most tokamaks which appear promising for relaxing t he plasma current constraint and therefore open the route to high-perf ormance steady-state operation with high bootstrap current fraction. P rospects of the weak or reversed magnetic shear scenarios for steady-s tate tokamak operation are presented in the light of recent experiment al progress to control pressure and current profiles with the combined use of various heating and current drive schemes. Implications of the present experiments on the modelling of future non-inductive operatio n in existing tokamaks and in ITER are addressed.