摘要
Beam-beam interactions cause dynamic behaviour of the charged particle beams in circular coUiders, which is directly related to their luminosity. The linear beam-beam force introduces an additional quadrupole that perturbs betatron motion of particles, including dynamic β, dynamic emittance and beam-beam tune-shifts; while the nonlinear force may excite resonances and cause tune-spread. With the weak-strong beam-beam mode, the linear and nonlinear effects are studied, dynamic βand dy- namic emittance as functions of tunes are analyzed, and formulas of beam-beam octupole caused tune-spread are derived, starting from beam-beam potential and equations of particle motions, and the measures to increase luminosity of BEPCII are discussed.
Beam-beam interactions cause dynamic behaviour of the charged particle beams in circular colliders,which is directly related to their luminosity.The linear beam-beam force introduces an additional quadrupole that perturbs betatron motion of particles,including dynamic dynamic emittance and beam-beam tune-shifts;while the nonlinear force may excite resonances and cause tune-spread.With the weak-strong beam-beam mode,the linear and nonlinear effects are studied,dynamic and dynamic emittance as functions of tunes are analyzed,and formulas of beam-beam octupole caused tune-spread are derived,starting from beam-beam potential and equations of particle motions,and the measures to increase luminosity of BEPCII are discussed.
