Damping of higher-order modes in a threefold symmetry accelerating structure

摘要

We investigate a waveguide-coupled damping structure with threefold symmetry using the 2-D and 3-D MAFIA codes. Within the frequency range considered, all higher order modes except the TM011 and TE111 modes are heavily damped. Possible ways to detrap these by using asymmetric waveguides offset with respect to the accelerating cavity in the direction of the beam are studied. External Qs and resonant frequencies are calculated using recently developed computer methods.