MOA1PL —  Plenary Session 1   (18-Jun-18   08:40—10:30)
Chair: Y.H. Chin, KEK, Ibaraki, Japan
Paper Title Page
MOA1PL01 Challenges in Understanding Space Charge Dynamics -1
  • H. Bartosik
    CERN, Geneva, Switzerland
  Space charge effects in high intensity and high brightness synchrotrons can lead to undesired beam emittance growth, beam halo formation and particle loss. A series of dedicated machine experiments has been performed over the past decade in order to study these effects in the particular regime of long-term beam storage (105-106 turns) as required for certain applications. This paper gives an overview of the present understanding of the underlying beam dynamics mechanisms. In particular it focuses on the space charge induced periodic resonance crossing, which has been identified as the main mechanism causing beam degradation in this regime. The challenges in further progressing with the understanding, the modelling and the mitigation of these space charge effects and the resulting beam degradation are discussed. Furthermore, an outlook for possible future directions of studies is presented.  
slides icon Slides MOA1PL01 [22.877 MB]  
MOA1PL02 Beam Dynamics Challenges for the LHC and Injector Upgrades -1
  • G. Rumolo
    CERN, Geneva, Switzerland
  The High Luminosity upgrade of the Large Hadron Collider (HL-LHC) will rely on significantly higher bunch current and brightness to meet the future yearly integrated luminosity target. The implications are twofold. On one side, all the accelerators of the LHC injection chain will have to be upgraded to produce the desired beam parameters. For this purpose, the LHC Injectors Upgrade (LIU) program has been established to implement all the needed modifications for meeting the required beam specifications. These upgrades will lead to the lifting of the main intensity and brightness limitations in the injectors, linked to beam instabilities driven by impedance or electron cloud (e-cloud), and space charge. On the other side, the LHC will have to be able to swallow the new beam parameters. This will mainly require control of impedance driven instabilities and beam-beam effects, and e-cloud mitigation. In this paper, we will focus on proton beams by describing the identified performance limitations of the LHC and its injectors, as well as the actions envisioned to overcome them.  
slides icon Slides MOA1PL02 [13.138 MB]  
MOA1PL03 Linac4 Commissioning Status and Challenges to Nominal Operation -1
  • G. Bellodi
    CERN, Geneva, Switzerland
  Linac4 will be connected to the Proton Synchrotron Booster (PSB) during the next long LHC shutdown in 2019 and it will operationally replace Linac2 as provider of protons to the CERN complex as of 2021. Commissioning to the final beam energy of 160 MeV was achieved by the end of 2016. Linac4 is presently under-going a reliability and beam quality test run to meet the beam specifications and relative tolerances requested by the PSB. In this paper we will detail the main challenges left before achieving nominal operation and we will re-port on the commissioning steps still needed for final validation of machine readiness before start of operation.  
slides icon Slides MOA1PL03 [20.659 MB]