Review of the EU Activities in Preparation of ITER in the Field of EC Power Sources and NB System

The European effort for the EC power sources is centred on the development of a 170 GHZ, 2 MW, CW coaxial cavity gyrotron of Collector Potential Depressed (CPD) type. 2.2 MW in single mode were demonstrated in short pulse operation on a pre-prototype gyrotron at FZK. Test on the first industrial gyrotron prototype will start before end 2006 in a new full performance EC test facility in Lausanne (CH). The procurement of the ITER NB system presents several challenges and an extensive R&D programme has been launched. In EU the experimental investigations take mainly place at CEA, Cadarache, where the arc driven source and the concept of an accelerator based on a single gap are pursued and at IPP, Garching, were a RF driven ion source is being developed. For the arc driven source, ITER baseline, the achieved current density is, in long pulses, still lower than the one required for ITER and the Cs consumptions is about three orders of magnitude higher than the one anticipated for ITER. Promising progresses have been made towards a RF driven ion source. Current densities of 330 A/m2 in H and 250 A/m2 in D were achieved on a small scale source with good reproducibility and operation in D in ITER relevant parameters space was achieved over many pulses. The RF driven ion source can now be considered a valid alternative to the arc driven one. Finally, the limited performances of the existing test facilities do not allow a reliable extrapolation to the ITER scale. The establishment of a full scale test facility has therefore become a centre piece of the European NB development strategy.