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Aumon, S.

Paper Title Page
TH6PFP034 Study of Beam Losses at Injection in the CERN Proton Synchrotron 3775
 
  • S. Aumon, S.S. Gilardoni, O. Hans, F.C. Peters
    CERN, Geneva
 
 

The maximum intensity the CERN PS has to deliver is continuously increasing. In particular, during the next years, one of the most intense beam ever produced in the PS, with up to 3000·1010 proton per pulse, should be delivered on a regular basis for the CNGS physics program. It is now known that the existing radiation shielding of the PS in some places is too weak and constitutes a major limitation due to large beam losses in specific locations of the machine. This is the case for the injection region: losses appear on the injection septum when the beam is injected in the ring and during the first turn, due also to an optical mismatch between the injection line and the PS. This paper presents the experimental studies and the simulations which have been made to understand the loss pattern in the injection region. Possible solutions to reduce the beam losses will be described, including the computation of a new injection optics.

 
FR5RFP050 Beam Instabilities Studies at Transition Crossing in the CERN Proton Synchrotron 4649
 
  • S. Aumon, W. Bartmann, S.S. Gilardoni, E. Métral, G. Rumolo, R.R. Steerenberg
    CERN, Geneva
  • B. Salvant
    EPFL, Lausanne
 
 

The CERN PS crosses transition energy at about 6 GeV by using a second order gamma jump performed with special quadrupoles. However, for high-intensity beams, and in particular the single bunch beam for the neutron Time-of-Flight facility, a controlled longitudinal emittance blow-up is still needed to prevent a fast single-bunch vertical instability from developing near transition. A series of studies have been done in the PS in 2008 to measure the beam behaviour near transition energy for different settings of the gamma transition jump. The purpose of this paper is to compare those measurements with simulations results from the HEADTAIL code, which should allow to understand better the different mechanisms involved and maybe improve the transition crossing.