Impedance spectrum for the PEP-II RF cavity

The impedance spectrum presented by the PEP-II RF cavity to the beam is calculated using a 3D MAFIA model which includes the damping waveguides and the input coupler. The simulation assumes that all the ports leading out of the cavity, including the beam pipes, are terminated in matched loads. The effect of the external loading on the longitudinal impedances will be examined. This study takes into account the input coupler damping which has not been considered in previous calculations.