Simulation of the beam halo from the beam-beam interaction.

SLAC-PUB-6379 October 1993 W Simulation of the Beam Halo from the Beam-Beam Interaction T. Chen, J. Irwin and R. Siemannt Stanford Linear Accelerator Center, Stanford University, Stanford, CA94309 Abstract: A new technique for simulating the beam halo in circular e+ecolliders is introduced, tested, and applied. Amplitude space is divided into core and halo regions, and only halo particles are tracked saving a factor of a hundred or more in CPU time. The methods for determining the regions, selecting and tracking particles, and connecting the core and halo are described. Results agree with conventional simulations. The beam halo is strongly influenced by nonlinear beam-beam resonances indicating that resonance streaming and phase convection are the dominant mechanisms for particles reaching large amplitudes.