Technological aspects of the different schemes for accelerator and ion source of the ITER Neutral Beam Injector

Each Injector of the ITER Neutral Beam system will deliver a power up to 16.5MW and guarantee steady operation for one hour in H or in D. To fulfil these requirements, the Neutral Beam Injector (NBI) must provide a current up to 40A of negative ions accelerated up to 1MV. At present two different schemes for the ion source and the accelerator are under investigation. In the framework of the European tasks in preparation for the ITER construction, the design of the NBI system based on the alternative concepts for these components has been performed including the related Power Supply, 1 MV Transmission Line and Bushing. In this paper the activities performed by Consorzio RFX on this area are presented and the main achievements discussed. In particular the design of the components for the alternative concepts are compared with those of the reference NBI design and the main technological aspects outlined and discussed