simulation code for space -charge driven resonant beam halo in high-intensity hadron synchrotrons

With the significant development of high-intensity hadron (proton and heavy ion) accelerator facilities, the space charge effect has become a major limiting factor for increasing beam intensity because it can drive particle resonance, forming beam halos and causing beam quality degradation or even beam loss. In studies on space charge, the particle-core model (PCM) has been widely adopted to describe halo particle formation. This code can be used to investigate the physical mechanism of the beam halo in high-intensity synchrotrons. In particular, a “1:1 parametric resonance” driven by the combined effects of space charge and dispersion is identified. A large dispersion is proven to have a damping effect on the 2:1 parametric resonance. The analysis based on the generalized PCM agrees with particle-in-cell simulations. A beam halo with large mismatch oscillations is also discussed.