Design of the conditioning system for the MITICA bias plate

The ITER Neutral Beam Test Facility (PRIMA) is plan ned to be built at Consorzio RFX (Padova, Italy). PRIMA includes two experimental devices: an ITER-si ze ion source with low voltage extraction called SPIDER and the prototype of the ITER Heating Neutra l Beam Injector (HNB) called MITICA. The purpose of MITICA is to demonstrate that all th e operational parameters of the ITER HNB accelerato r can be experimentally achieved with reasonable marg in, thus establishing a large step forward in the performances of neutral beam injectors in compariso n with the present experimental devices. The design of the MITICA accelerator, here describe d in detail, has been developed in order to satisfy with reasonable margin all the operational requirements of the ITER HNB. An integrated approach, taking int o consideration at the same time physics and engineer ing aspects, has been adopted throughout the design process. The aim of this report is to finalize the design of the MITICA bias plate, by choosing the most suitab le dimensions of the cooling channels, in order to obt ain a fair distribution of water among the cooling systems of the plasma grid, of the extractor support system and of the bias plate.