Preliminary ICRF studies on JET

As a first step in the JET ICRF programme, two antenna generator units have been installed at JET and operated up to the design specifications of 3 MW coupled in the Torus for 1 second. After a brief description of th esystem, the experimental results of wave coupling to the plasma and matching the plasma loaded antenna are discussed. The first heating results are presented concentrating on the analysis of a case where the total power to te plasma increases by a ratio 2.5. The main results are: a peak power deposition profile generating large internal temperature relaxation (giant sawteeth) , a comparison of results using antennae with different wavelength radiation patternsand the low level ofimpurity effect.