Radio frequency quadrupole cavity structure for particle accelerators — Simulation and measurements

EM simulation of long RFQ with quadruple ridge (vane) waveguide structure with narrow vane gaps and vane end cutbacks is a complex and challenging task. Advances in 3-D EM simulation tools in recent years can lead to accurate analysis of such structures. Here, we present the simulation of long RFQs (over 2λ), validate our results with measurements, compare simulated results of eigenmode frequencies and field distribution to measured values, and finally extend our analysis to an alternative and very promising design noted as double dipole structure. Excellent agreement between measurement and simulation has been attained and design comparison between the long double dipole and the traditional RFQs has been developed.