Author: Arduini, G.
Paper Title Page
MOP248 Brightness Evolution for LHC Beams during the 2012 Run 170
 
  • M. Kuhn
    Uni HH, Hamburg, Germany
  • G. Arduini, J.F. Comblin, A. Guerrero, V. Kain, B. Mikulec, F. Roncarolo, M. Sapinski, M. Schaumann, R. Steerenberg
    CERN, Geneva, Switzerland
 
  One of the reasons for the remarkable achievements of the LHC is the excellent performance of the LHC injector chain. The evolution of the brightness in the injectors and at LHC collision in 2011 and 2012 is discussed. During certain run periods, the brightness from the beam provided by the injectors was lower than usual. Some of the issues have been identified so far and will be reported. The latest results on emittance blow-up investigations through the 2012 LHC cycle will also be presented and compared to the 2011 data. Possible implications for LHC upgrade scenarios will be mentioned.  
 
TUO1A01 The High Intensity/High Brightness Upgrade Program at CERN: Status and Challenges 226
 
  • S.S. Gilardoni, G. Arduini, T. Argyropoulos, S. Aumon, H. Bartosik, E. Benedetto, N. Biancacci, T. Bohl, J. Borburgh, C. Carli, F. Caspers, H. Damerau, J.F. Esteban Müller, V. Forte, R. Garoby, M. Giovannozzi, B. Goddard, S. Hancock, K. Hanke, A. Huschauer, G. Iadarola, M. Meddahi, G. Métral, B. Mikulec, E. Métral, Y. Papaphilippou, S. Persichelli, G. Rumolo, B. Salvant, F. Schmidt, E.N. Shaposhnikova, R. Steerenberg, G. Sterbini, M. Taborelli, H. Timko, M. Vretenar, R. Wasef, C. Yin Vallgren, C. Zannini
    CERN, Geneva, Switzerland
  • G. Franchetti
    GSI, Darmstadt, Germany
  • M. Migliorati
    University of Rome "La Sapienza", Rome, Italy
  • A.Y. Molodozhentsev
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • M.T.F. Pivi
    SLAC, Menlo Park, California, USA
  • V.G. Vaccaro
    Naples University Federico II, Mathematical, Physical and Natural Sciences Faculty, Napoli, Italy
 
  The future beam brilliance and intensities required by the HL-LHC (High-Luminosity LHC) project and for possible new neutrino production beams triggered a deep revision of the LHC injector performances. The analysis, progressing in the framework of the LHC Injectors Upgrade (LIU) projects, outlined major limitations mainly related to collective effects - space charge in PSB and PS, electron cloud driven and TMCI instabilities in the SPS, longitudinal coupled bunch instabilities in the PS for example - but also to the existing hardware capability to cope with beam instabilities and losses. A summary of the observations and simulation studies carried out so far, as well as the future ones, will be presented. The solution proposed to overcome the different limitations and the plans for their implementation will be also briefly reviewed.  
slides icon Slides TUO1A01 [12.748 MB]  
 
WEO1A02 LHC Impedance Model: Experience with High Intensity Operation in the LHC 349
 
  • B. Salvant, O. Aberle, G. Arduini, R.W. Aßmann, V. Baglin, M.J. Barnes, P. Baudrenghien, A. Bertarelli, C. Bracco, R. Bruce, X. Buffat, F. Carra, F. Caspers, G. Cattenoz, S.D. Claudet, H.A. Day, J.F. Esteban Müller, M. Garlaschè, L. Gentini, B. Goddard, A. Grudiev, B. Henrist, W. Herr, S. Jakobsen, R.J. Jones, G. Lanza, L. Lari, T. Mastoridis, N. Mounet, E. Métral, A.A. Nosych, J.L. Nougaret, S. Persichelli, T. Pieloni, A.M. Piguiet, S. Redaelli, F. Roncarolo, G. Rumolo, B. Salvachua, M. Sapinski, E.N. Shaposhnikova, L.J. Tavian, M.A. Timmins, J.A. Uythoven, A. Vidal, R. Wasef, D. Wollmann
    CERN, Geneva, Switzerland
  • A.V. Burov
    Fermilab, Batavia, USA
  • S.M. White
    BNL, Upton, Long Island, New York, USA
 
  The CERN Large Hadron Collider (LHC) is now in luminosity production mode and has been pushing its performance in the past months by increasing the proton beam brightness, the collision energy and the machine availability. As a consequence, collective effects have started to become more and more visible and have effectively slowed down the performance increase of the machine. Among these collective effects, the interaction of brighter LHC bunches with the longitudinal and transverse impedance of the machine has been observed to generate beam induced heating and transverse instabilities since 2010. This contribution reviews the current LHC impedance model obtained from theory, simulations and bench measurements as well as a selection of measured effects with the LHC beam.  
slides icon Slides WEO1A02 [7.991 MB]  
 
WEO1B01 Low Gamma Transition Optics for the SPS: Simulation and Experimental Results for High Brightness Beams 381
 
  • H. Bartosik, G. Arduini, T. Argyropoulos, T. Bohl, K. Cornelis, J.F. Esteban Müller, K.S.B. Li, Y. Papaphilippou, G. Rumolo, B. Salvant, F. Schmidt, E.N. Shaposhnikova, H. Timko
    CERN, Geneva, Switzerland
  • A.Y. Molodozhentsev
    KEK, Ibaraki, Japan
 
  The single bunch transverse mode coupling instability (TMCI) at injection is presently one of the main intensity limitation for LHC beams in the SPS. A new optics for the SPS with lower transition energy yields an almost 3-fold increase of the slip factor at injection energy and thus a significantly higher TMCI threshold, as demonstrated both in simulations and in experimental studies. It is observed furthermore that the low gamma transition optics yields better longitudinal stability throughout the entire acceleration cycle. In addition, simulations predict a higher threshold for the electron cloud driven single bunch instability, which might become an important limitation for high intensity LHC beams with the nominal 25 ns bunch spacing. This contribution gives a summary of the experimental and simulation studies, addressing also space charge effects and the achievable brightness with high intensity single bunch beams.  
 
WEO1B05 PTC-Orbit Studies for the CERN LHC Injectors Upgrade Project 399
 
  • A.Y. Molodozhentsev, E. Forest
    KEK, Ibaraki, Japan
  • G. Arduini, H. Bartosik, E. Benedetto, C. Carli, M. Fitterer, V. Forte, S.S. Gilardoni, M. Martini, N. Mounet, E. Métral, F. Schmidt, R. Wasef
    CERN, Geneva, Switzerland
 
  The future improvement of the beam brilliance and intensities required in the frame of the LIU (LHC Injectors Upgrade) project to reach the demands of the HL-LHC (High-Luminosity LHC) project triggered a comprehensive study of the combined effects of the space charge and the machine resonances for the CERN synchrotrons, which are the injector chain for LHC. In frame of this report we will summarize new features of the PTC-ORBIT code which allow the beam dynamics modeling in the LHC injectors taking into account the time variation of the machine parameters during the injection process. The measurements, obtained during recent MD companies, and simulations for the low-energy high-intensity beams, will be discussed.  
slides icon Slides WEO1B05 [3.063 MB]