Dynamic aperture measurement at the VEPP-4M storage ring

Dynamic aperture has been studied experimentally at the VEPP-4M electron-positron collider. A transverse bunch motion was excited by fast kickers. The beam intensity and the amplitude of the coherent oscillations were measured turn-by-turn by the BPM. In this paper the technique of determining the dynamic/physical aperture is described. Several methods of increasing the dynamic aperture are discussed. The results of computer simulation and simple model analytic prediction explaining the experimental data are presented.