INSTALLATION AND COMMISIONNING OF THE EU TEST FACILITY FOR ITER GYROTRONS D.Fasel 1 , S.Alberti 1 , T.Bonicelli 2 , E.Droz 1 , T.Goodman 1 , M-A.Henderson 1 , JP.Hogge 1 , X.LLobet 1 , B.Marletaz 1 , Ph.Marmillod 1 , A.Perez 1 , L.Porte 1 , U.Siravo 1 , MQ.Tran 1 1 Centre de Recherches en Physique des Plasmas (CRPP) CH-1015 Lausanne / Switzerland 2 EFDA-CSU, Max Planck Institut, Boltzmannstr. 2, D-85748 Garching / Germany In the frame of the EU program on the ITER Electron Cyclotron Wave (ECW) system, the development of a 170 GHz, 2 MW CW coaxial gyrotron with depressed collector (C-GT170) has been launched during the 6 th Framework Program (2003-2006) in the European Technology Workplan. Such development relies on the availability of a Test Facility (TF) capable of providing both the energy sources and sinks required by this new electron tube (electrical energy, cooling capacity), and allowing the control and acquisition of a large range of signals used to understand and improve the gyrotron behaviour. The TF will be used, in a later stage, for the component test of the ITER ECW system. This paper will report on the design, installation and commissioning of the TF in Lausanne. Keywords: gyrotron, Test Facility (TF), HV power supplies (HVPS), SuperConducting Magnet (SCM), Radio Frequency Conditioning Unit (RFCU) 1. Introduction One of the additional heating principles proposed for ITER is based on electron cyclotron waves, making use of RF power sources, named gyrotrons. In this context, European Community decided to launch, through the European Technology Workplan, a gyrotron development aiming at a higher RF power unit. Refer to [1] and [2] for the details on the gyrotron design and parameters. Among several advantages, the use of higher RF power units (2MW compared to 1MW for the present ITER design) is to minimise the requirements in auxiliary systems (i.e. PS, SCM, transmission line, launcher etc.) and in the infrastructure to be installed with each RF source independently of the RF power delivered. Such development implies also to be able to test the gyrotron prototype at full range, in similar conditions to the ones imposed by ITER installation rules. Following a design study (refer to [3] for the details) a Test Facility (TF) has been designed and installed at CRPP premises, on the EPFL (Ecole Polytechnique Federale de Lausanne, Switzerland) site. This TF will offer the opportunity to have available a RF installation integrating all the ITER requirements, which will allow to operate the first gyrotron prototype tests in the second half of 2006. It could also be considered as a test bench for other gyrotrons to be installed on the ITER site. In parallel to this development, the design of the ITER ECH upper launchers has started (see [4] for details), both spare space and infrastructure have been integrated in the TF design to be able to test prototype parts of ITER launcher at high power and/or for long pulse operation. The following sections describe the main equipments forming this TF for the ITER Electron Cyclotron RF (ECRF) power sources. 2. Power supplies Figure 1 presents the electrical supply structure selected to power a gyrotron of the depressed collector type. Two HV power supplies are used to generate the acceleration voltage (or beam voltage): > the Main HV Power Supply (MHVPS) powering the gyrotron cathode and drawing the main electrical power to the gyrotron. > The Body PS (BPS), connected to the depressed part of the collector, is used to apply the decelerating potential to the electron beam after the electrons have transferred their kinetic energy to generate the microwave beam.