H-mode in JET with ion cyclotron resonance heating alone

H-mode discharges with ion cyclotron resonance heating (ICRH) alone have been achieved in JET, up to a power level of 12 MW. These H-modes, which have reached durations of up to 1.5 s, have all the characteristics of H-modes with neutral beam injection. In particular, the energy confinement is similar to that of neutral beam cases and typically corresponds to two times Goldston L-mode scaling. The ICR heated H-modes are characterized by long sawtooth free periods. The use of beryllium gettering is an important factor in these experiments.