• A. Pepato, R. Dima, F. Scantamburlo
  INFN- Sez. di Padova, Padova
• M. Comunian, E. Fagotti, F. Grespan, A. Palmieri, A. Pisent, C. Roncolato
  INFN/LNL, Legnaro (PD)
• D. Dattola, P. Mereu
  INFN-Torino, Torino

In the framework of the IFMIF/EVEDA project, the RFQ is a 9.8 m long cavity, with very challenging mechanicals specification. In the base line design, the accelerator tank is composed of 18 modules that are flanged together. The construction procedure of each module foresees the horizontal brazing of the four electrodes and then the vertical brazing of the flanges. A RFQ prototype, composed of 2 modules, aimed at testing all the mechanical construction procedure is under construction. In this article, the progress of the prototype construction and the progresses in the design and engineering phase, as well the description of all the fabrication phases is reported.

• A. Palmieri, F. Grespan
  INFN/LNL, Legnaro (PD)
• G. Cotto
  Torino University, ., Torino
• D. Dattola, P. Mereu
  INFN-Torino, Torino

In order to validate the tuning and stabilization procedures established for the IFMIF RFQ, a campaign of low power tests on an aluminum real-scale RFQ built on purpose has been carried out. Such campaign consisted of the determination of mode spectra, the measurements of the electric field distribution with bead pulling technique, and the implementation of the tuning procedure. The main outcomes and results obtained are reported in the article.

• A. Palmieri, F. Grespan, A. Pisent
  INFN/LNL, Legnaro (PD)

An important issue for high intensity RFQs (tenth of mA beam current and more) is the necessity of keeping the beam losses as low as possible, in order to allow reliable and safe maintenance of the machine. Typically, beam dynamics outcomes driven by these constraints result both in a RFQ length that is considerably higher than the wavelength and in an intra-vane voltage admitted variation with respect to the design value that must not exceed a few percent. Therefore an analytical tool is needed in order to foresee the effect of geometric perturbations on the voltage profile, in order to give an indication on the permitted ranges of geometrical errors in the RFQ construction. In this article a five conductors transmission line equivalent circuit for the four-vane RFQ is presented and the effects of geometrical perturbations on the voltage profile are analyzed in some particular cases. The case study is the IFMIF RFQ (125 mA deuteron current, 9.8 m length, 175 MHz frequency), whose features are particularly suitable for this kind of analysis.

• A. Mosnier, P.-Y. Beauvais, R. Gobin, J.-F. Gournay, P. Joyer, J. Marroncle, P.A.P. Nghiem, F. Orsini
  CEA, Gif-sur-Yvette
• B. Brañas, A. Ibarra, P. Méndez, I. Podadera Aliseda, J. Sanz, F. Toral
  CIEMAT, Madrid
• M. Comunian, A. Facco, A. Palmieri, A. Pepato, A. Pisent
  INFN/LNL, Legnaro (PD)
• P. Garin, Ch. Vermare
  IFMIF/EVEDA, Rokkasho
• R. Heidinger
  Fusion for Energy, Garching
• H. Kimura, T. Kojima, T. Kubo, S. Maebara, S. O'hira, Y. Okumura, K. Shinto, H. Takahashi, K. Yonemoto
  JAEA, Aomori

The objectives of the IFMIF/EVEDA project are to produce the detailed design of the entire IFMIF facility, as well as to build and test a number of prototypes, including a high-intensity CW deuteron accelerator (125 mA @ 9 MeV). Most of the accelerator components (Injector, RFQ, Superconducting RF-Linac, Transport Line and Beam Dump, RF Systems, Local control systems, beam instrumentation) are designed and provided by European institutions (CEA/Saclay, CIEMAT, INFN/LNL, SCK-CEN), while the RFQ couplers, the supervision of the control system and the building including utilities constructed at Rokkasho BA site are provided by JAEA. The coordination between Europe and Japan is ensured by an international project team, located in Rokkasho, where the accelerator will be installed and commissioned. The design and R&D activities are presented, as well as the schedule of the prototype accelerator.