An amplitude and frequency controlled oscillator (AFCO) for Alfvén-wave heating in the Lausanne TCA tokamak

The new RF system for the Lausanne TCA Tokamak experiment is described. The generator operates from 0.3 to 5 MHz and can transfer 1 MW to the plasma for 120 ms in the Alfven-wave heating (AWH) range. The frequency and the amplitude of the pulse are pre-programmed; an optional feedback control is proposed. The authors also discuss the method of estimating the RF energy transferred to the plasma. A short comment is made concerning some technical problems of AWH in large Tokamaks.