Author: Lallement, J.-B.
Paper Title Page
THPB011 Linac4 45 keV Proton Beam Measurements 867
  • G. Bellodi, V.A. Dimov, L.M. Hein, J.-B. Lallement, A.M. Lombardi, O. Midttun, R. Scrivens
    CERN, Geneva, Switzerland
  • P.A. Posocco
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  Linac4 is a 160 MeV normal-conducting H linear accelerator, which will replace the 50 MeV proton Linac (Linac2) as injector for the CERN proton complex. Commissioning of the low energy part - H source, a 45 keV Low Energy Beam Transport line (LEBT), a 3 MeV RFQ and a Medium Energy Beam Transport (MEBT) line - will start in fall 2012 on a dedicated test stand installation. In preparation to this, preliminary measurements were taken in the past few months using a 45 keV proton source and a temporary LEBT setup, with the aim of characterising the output beam by comparison with simulations. This also allowed a first verification of the diagnostics instrumentation and acquisition software tools. Measurements of beam profile, emittance and intensity were taken after the source, after the first and after the second LEBT solenoids respectively. Particle distributions were reconstructed from emittance scans and used as input to simulation studies of the beam transport through the line. Comparison of the results with the measurements allowed an experimental validation of the LEBT (in terms of misalignments and calibration points) and qualification of the beam at the source output.  
THPB038 Assembly and RF Tuning of the Linac4 RFQ at CERN 939
  • C. Rossi, A. Dallocchio, J. Hansen, J.-B. Lallement, A.M. Lombardi, S.J. Mathot, D. Pugnat, M.A. Timmins, G. Vandoni, M. Vretenar
    CERN, Geneva, Switzerland
  • M. Desmons, A. France, Y. Le Noa, J. Novo, O. Piquet
    CEA/DSM/IRFU, France
  The fabrication of Linac4 is progressing at CERN with the goal of making a 160 MeV H beam available to the LHC injection chain as from 2015. In the Linac4 the first stage of beam acceleration, after its extraction from the ion source, is provided by a Radiofrequency Quadrupole accelerator (RFQ), operating at the RF frequency of 352.2 MHz and which accelerates the ion beam to the energy of 3 MeV. The RFQ, made of three modules, one meter each, is of the four-vane kind, has been designed in the frame of a collaboration between CERN and CEA and has been completely machined and assembled at CERN. The paper describes the assembly of the RFQ structure and reports the results of RF low power measurements, in order to achieve the required accelerating field flatness within 1% of the nominal field profile.  
THPB010 Progress in the Construction of Linac4 at CERN 864
  • M. Vretenar, L. Arnaudon, P. Baudrenghien, G. Bellodi, C. Bertone, Y. Body, J.C. Broere, O. Brunner, M.C.L. Buzio, C. Carli, J.-P. Corso, J. Coupard, A. Dallocchio, N. Dos Santos, J.-F. Fuchs, A. Funken, R. Garoby, F. Gerigk, L. Hammouti, K. Hanke, J. Hansen, I. Kozsar, J.-B. Lallement, J. Lettry, A.M. Lombardi, L.A. Lopez Hernandez, C. Maglioni, S.J. Mathot, B. Mikulec, D. Nisbet, M.M. Paoluzzi, B. Puccio, U. Raich, S. Ramberger, F. Roncarolo, C. Rossi, N. Schwerg, R. Scrivens, G. Vandoni, J. Vollaire, R. Wegner, S. Weisz, Th. Zickler
    CERN, Geneva, Switzerland
  As first step of the LHC luminosity upgrade program CERN is building a new 160 MeV H¯ linear accelerator, Linac4, to replace the ageing 50 MeV Linac2 as injector to the PS Booster (PSB). Linac4 is an 86-m long normal-conducting linac made of a 3 MeV injector followed by 22 accelerating cavities of three different types. The general service infrastructure has been installed in the new tunnel and surface building and its commissioning is progressing; high power RF equipment is being installed in the hall and installations in the tunnel will start soon. Construction of the accelerator parts is in full swing involving industry, the CERN workshops and a network of international collaborations. The injector section including a newly designed and built H¯ source, a 3-m long RFQ and a chopping line is being commissioned in a dedicated test stand. Beam commissioning of the linac will take place in steps of increasing energy between 2013 and 2014. From end of 2014 Linac4 could deliver 50 MeV protons in case of Linac2 failure, while 160 MeV H¯ could be injected into the PSB from end of 2015; the exact start of the LHC shut-down required for connection will be coordinated with its experiments.