Author: Arnaudon, L.
Paper Title Page
MOPC054 The LHC RF System - Experience with Beam Operation 202
 
  • P. Baudrenghien, M. E. Angoletta, T. Argyropoulos, L. Arnaudon, J. Bento, T. Bohl, O. Brunner, A.C. Butterworth, E. Ciapala, F. Dubouchet, J. Esteban Muller, D.C. Glenat, G. Hagmann, W. Höfle, D. Jacquet, M. Jaussi, S. Kouzue, D. Landre, J. Lollierou, P. Maesen, P. Martinez Yanez, T. Mastoridis, J.C. Molendijk, C. Nicou, J. Noirjean, G. Papotti, A.V. Pashnin, G. Pechaud, J. Pradier, J. Sanchez-Quesada, M. Schokker, E.N. Shaposhnikova, D. Stellfeld, J. Tückmantel, D. Valuch, U. Wehrle, F. Weierud
    CERN, Geneva, Switzerland
 
  The LHC RF sys­tem com­mis­sion­ing with beam and physics op­er­a­tion for 2010 and 2011 are pre­sent­ed. It be­came clear in early 2010 that RF noise was not a life­time lim­it­ing fac­tor: the cross­ing of the much feared 50 Hz line for the syn­chrotron fre­quen­cy did not af­fect the beam. The broad­band LHC RF noise is re­duced to a level that makes its con­tri­bu­tion to beam dif­fu­sion in physics well below that of Intra Beam Scat­ter­ing. Cap­ture loss­es are also under con­trol, at well below 0.5%. Lon­gi­tu­di­nal emit­tance blow-up, need­ed for ramp­ing of the nom­i­nal in­ten­si­ty sin­gle bunch, was rapid­ly com­mis­sioned. In 2011, 3.5 TeV/beam physics has been con­duct­ed with 1380 bunch­es at 50 ns spac­ing, cor­re­spond­ing to 55% of the nom­i­nal cur­rent. The in­ten­si­ty per bunch (1.3 ·1011 p) is sig­nif­i­cant­ly above the nom­i­nal 1.15 ·1011. By Au­gust 2011 the LHC has ac­cu­mu­lat­ed more than 2 fb-1 in­te­grat­ed lu­mi­nos­i­ty, well in ex­cess of the 1 fb-1 tar­get for 2011.  
 
TUOAA03 The Linac4 Project at CERN 900
 
  • M. Vretenar, L. Arnaudon, P. Baudrenghien, C. Bertone, Y. Body, J.C. Broere, O. Brunner, M.C.L. Buzio, C. Carli, F. Caspers, J.-P. Corso, J. Coupard, A. Dallocchio, N. Dos Santos, R. Garoby, F. Gerigk, L. Hammouti, K. Hanke, M.A. Jones, I. Kozsar, J.-B. Lallement, J. Lettry, A.M. Lombardi, L.A. Lopez Hernandez, C. Maglioni, S.J. Mathot, S. Maury, B. Mikulec, D. Nisbet, C. Noels, M.M. Paoluzzi, B. Puccio, U. Raich, S. Ramberger, C. Rossi, N. Schwerg, R. Scrivens, G. Vandoni, J. Vollaire, S. Weisz, Th. Zickler
    CERN, Geneva, Switzerland
 
  As the first step of a long-term pro­gramme aim­ing at an in­crease in the LHC lu­mi­nos­i­ty, CERN is build­ing a new 160 MeV H lin­ear ac­cel­er­a­tor, Linac4, to re­place the age­ing 50 MeV Linac2 as in­jec­tor to the Pro­ton-Syn­chrotron Boost­er (PSB). Linac4 is an 86-m long nor­mal-con­duct­ing linac made of an H source, a Radio Fre­quen­cy Quadrupole (RFQ), a chop­ping line and a se­quence of three ac­cel­er­at­ing struc­tures: a Drift-Tube Linac (DTL), a Cell-Cou­pled DTL (CCDTL) and a Pi-Mode Struc­ture (PIMS). The civil en­gi­neer­ing has been re­cent­ly com­plet­ed, and con­struc­tion of the main ac­cel­er­a­tor com­po­nents has start­ed with the sup­port of a net­work of in­ter­na­tion­al col­lab­o­ra­tions. The low-en­er­gy sec­tion up to 3 MeV in­clud­ing a 3-m long 352 MHz RFQ en­tire­ly built at CERN is in the final con­struc­tion phase and is being in­stalled on a ded­i­cat­ed test stand. The pre­sent sched­ule fore­sees beam com­mis­sion­ing of the ac­cel­er­a­tor in the new tun­nel in 2013/14; the mo­ment of con­nec­tion of the new linac to the CERN ac­cel­er­a­tor chain will de­pend on the LHC sched­ule for long shut-downs.  
slides icon Slides TUOAA03 [10.347 MB]