• M. Eshraqi, M. Brandin, I. Bustinduy, C.J. Carlile, H. Hahn, M. Lindroos, C. Oyon, S. Peggs, A. Ponton, K. Rathsman
  ESS, Lund
• R. Calaga, T. Satogata
  BNL, Upton, Long Island, New York
• A. Jansson
  Fermilab, Batavia

A three year design update for the European Spallation Source (ESS) linac is just starting and a full review of this work will be presented. The acceleration in the medium energy part of the LINAC using the spoke cavities have been optimized and the rest of the machine has been redesigned to incorporate this optimization. The ESS LINAC will deliver an average power of 5~MW to the target in the nominal design and the possibility to upgrade to 7.5~MW has been included in all the design steps.

Acknowledgments to all the people in the ESS LINAC Reference Group.

• I. Bustinduy, D. Fernandez-Cañoto, D. de Cos
  ESS Bilbao, Bilbao
• J. Alonso, M. Eguiraun, R. Enparantza, M. Larrañaga
  Fundación TEKNIKER, Eibar (Gipuzkoa)
• F.J. Bermejo
  Bilbao, Faculty of Science and Technology, Bilbao
• V. Etxebarria, J. Jugo, J. Portilla
  University of the Basque Country, Faculty of Science and Technology, Bilbao
• D.C. Faircloth, S.R. Lawrie, A.P. Letchford
  STFC/RAL/ISIS, Chilton, Didcot, Oxon
• J. Feuchtwanger
  ESS-Bilbao, Zamudio
• S. Jolly
  Imperial College of Science and Technology, Department of Physics, London
• J. Lucas
  Elytt Energy, Madrid

The rationale behind the Bilbao Accelerator Ion Source Test Stand (ITUR) project is to perform a comparison between different kinds of hydrogen ion sources using the same beam diagnostics setup. In particular, a direct comparison will be made in terms of the emittance characteristics of Penning-type sources such as those currently being used in ISIS (UK) and those of microwave type such as CEA-Saclay and INFN. The aim here pursued is to build an Ion Source Test Stand where virtually any type of source can be tested and, thus, compared to the results of other sources under the same gauge. It would then be possible to establish a common ground for effectively comparing different ion sources. The work here presented reports on the first simulations for the H-/H⁺ extraction system, as well the devices that conform the diagnostic vessel: Faraday Cup, Pepperpot and Retarding Potential Analyzer (RPA), among others.

• I. Bustinduy, N. Garmendia, H. Hassanzadegan, D. de Cos
  ESS Bilbao, Bilbao
• F.J. Bermejo
  Bilbao, Faculty of Science and Technology, Bilbao
• V. Etxebarria, J. Portilla
  University of the Basque Country, Faculty of Science and Technology, Bilbao
• J. Feuchtwanger
  ESS-Bilbao, Zamudio
• S. Jolly, J.K. Pozimski, P. Savage
  Imperial College of Science and Technology, Department of Physics, London
• A.P. Letchford
  STFC/RAL/ISIS, Chilton, Didcot, Oxon

The main objective of the Bilbao Front End Test Stand (ETORFETS) is to set up a facility to demonstrate experimentally the design ideas for the future ESS LINAC that are being proposed in discussion forums by the technical scientific community. ETORFETS is focused on the first stage of the linear accelerator, namely, that of the Radio-Frequency Quadrupole (RFQ) and its pre and post beam transport systems. The RFQ bunches, focuses transverse and longitudinally, and accelerates charged particles in the low-energy range (up to ~ 3 MeV), thus becoming one of the main components of the accelerating structure. The first RFQ simulations, performed in Superfish and GPT software packages, will be presented in this work.