Ion cyclotron heating on TEXTOR has now reached the Megajoule level. The heating scenario is normally mode conversion but occasionally minority heating in a D-(H) plasma. With appropriate wall conditioning by carbonization more than 1 MW of RF power has been injected for long pulse durations ( approximately 1 s). The ICRF heated plasma is characterized by a quasi-stationarity of all plasma parameters, little if no impurity increase and a loop voltage reduction resulting in the total power coupled to the plasma reaching six times the remaining ohmic power input. Evidence of the coupling of the RF power to the plasma is obtained from the increase of the thermal load on the limiters and central energy deposition is supported from analysis of the sawtooth heating rate.
The first ICRF heating experiment in the large helical device