Particle-core study of halo dynamics in periodic-focusing channels

This paper reports on an approach to investigate the dynamics of halo parti cles in mismatched charged-particle beams propagating through periodic-focu sing channels using the particle-core model. The proposed method employs ca nonical transformations to minimize, in new phase-space variables, the flut ter due to the periodic focusing to allow making stroboscopic plots. Applyi ng this method, we find that in periodic-focusing systems, certain particle s initially not in the halo region can be brought into resonance with the c ore oscillation to become halo particles. PACS number(s): 41.85.-p, 29.17.w, 29.27.Bd.