THPM6Y —  Parallel Session   (07-Jul-16   16:20—16:40)
Chair: Y. He, IMP/CAS, Lanzhou, People's Republic of China
Paper Title Page
THPM6Y01
 Collective Beam Instability and Beam Halo Due to Space Charge  
 
  • C. Li, Zh.C. Liu, Q. Qin
    IHEP, Beijing, People's Republic of China
  • R.A. Jameson
    IAP, Frankfurt am Main, Germany
  
  The collective mode instability in high intensity ion beam induced by space charge has been studied for several decades. Beam halo also will be formed if beam is located in the collective mode unstable stop band. In this paper, firstly we clearly show that the beam surface is distorted by the space charge potential perturbation; the formed n-fold structure is in particular to the nth order unstable collective mode. Secondly, the formed n-fold structure will lead to beam halo with beam evolution. The halo mechanism could be depicted by resonance between single particle and oscillation collective mode. Finally, we proved that the halo particles are those whose actions were modified significantly by the nonlinear space charge and resonance.  
slides icon Slides THPM6Y01 [1.318 MB]