Simulation of coupled bunch instability

The beam dynamics of coupled bunch instability is studied using simulation method in this paper. The code SCBI (Simulation of Coupled-Bunch Instabilit ies) is developed. This code can be used to study the multi-bunch instabili ties including the effects of long range and mediate range wake field due t o RF HOMs, resistive wall and other cavity shape element along the ring. Th e simulation results using SCBI are compared with those of ZAP when bunches are symmetrically distributed, showing a good agreement with each other. T he code SCBI has been used to study the multi-bunch instability in BEPCII.