Investigation of longitudinal beam distributions due to potential-well distortion in the PLS storage ring

In this paper, we examine the effect of the wakefields generated by an interaction between the circulating electron beam and the rf cavities and components of vacuum chambers on the longitudinal beam distribution, with particular emphasis on the Pohang Light Source (PLS) storage ring. In order to obtain an equilibrium longitudinal beam distribution for a single beam, we utilized both a numerical solution of the Vlasov equation and a multi-particle tracking method. Results show that the impedance due to the beam-cavity interaction affects the longitudinal beam deformation less than the broadband impedance in the ring does. The results of the Vlasov method are shown to be in good agreement with those of the multi-particle tracking method