"arnold Diffusion" and Diffusion Enhancement by the Beam-Beam Intraction

Results and analyses of computer simulations of the beam-beam interaction in the "Tevatron" p¿p collider are presented. Long-time simulations of this nonlinear two-dimensional (2-D) interaction are undertaken in a search for beam blow-up due to "Arnold Diffusion". No large blow-up is seen in simulation of 20 minutes Tevatron time (60 million turns). In separate investigations it is found that the non-linear interaction can enhance diffusion from external sources, if a low order non-linear resonance be within the "tune spread". A nodel to describe this enhancement is presented.