THE 1.8 MW - 433 MHz RF SYSTEM FOR THE ION BERNSTEIN WAVES EXPERIMENT ON FTU

A RF heating experiment at a frequency of 433 MHz, utilizing ion Bernstein waves, is under development on FTU. The frequency is near to the fourth harmonic of the proton cyclotronic resonance frequency at B = 7.8 Tesla. It is sufficiently high to allow the coupling with the plasma by means of rectangular waveguides, instead of loop antennas, with a sufficiently large coupling coefficient. The power will be generated by three klystron amplifiers, each capable of supplying 600 kW for 1s, driven by three solid-state low-power amplifiers. The RF power will be delivered to the waveguide grills by means of rigid coaxial transmission lines. The paper reports the main characteristics of the system.