Measurement and simulation of nonlinear beam-beam mode coupling in the Fermilab Tevatron

Abstract

The Tevatron beam dynamics has been studied from the "weak-strong" representation of the beam-beam effects for various octupole field settings. A single particle is tracked using TEAPOT in the presence of the other beam. The nonlinearities introduced by the beam-beam forces introduces two unwanted effects: (1) it excites nonlinear resonances; (2) it introduces dispersion of the tunes with amplitude. The strength of nonlinear three mode coupling satisfying the sum rules v/sub 3/=v/sub 1//spl plusmn/v/sub 2/ for various octupole settings are calculated. The higher order spectral analysis results are presented.