Coupling Network Simulation for the PEP-II RF Cavity*

Two different input coupling networks are being pro-posed for the PEP-II RF cavity: a loop type and an aper-ture type. Both designs are expected to provide a varying coupling factor ranging from three to ten and to handle up to 500 kW of transmitted power. For beam stability reasons, it is further desirable for the coupling network to couple out any HOM’s that are not adequately damped by the dedicated waveguides. This paper evaluates the coupling factors for the two types of input couplers using MAFIA, and estimates the additional damping they pro vide to the TMczi mode which has the highest residual impedance after the effect of the damping waveguides is included. Peak power densities at areas of high current concentration will also be presented. 1