ICRF heating and profile control techniques in TFTR

In fast wave to ion Bernstein wave made conversion experiments in DT supers hot plasmas, localized efficient ion heating rather than electron heating w as observed, which was due to Doppler broadened tritium cyclotron resonance overlap into the mode conversion region. The ion temperature heat pulse as sociated with RF power modulation in this regime could provide a diagnostic tool for measuring the local ion thermal conductivity in various confineme nt regimes. In direct launch ion Bernstein wave heating experiments, core p ower coupling was limited by the excitation of parasitic edge modes. Howeve r, a sheared poloidal flow was observed that is consistent in both magnitud e and direction with theoretical models based on RF driven Reynolds stress. With the modest power coupled to the core (similar to 360 kW), the magnitu de of the shear in the observed flow was estimated to be a factor of 3-4 to o low to trigger transport barrier formation through localized shear suppre ssion of turbulence.