Progress report on two-bunch excitation of wakefield in dielectric structures

Wakefield accelerators have the potential to achieve accelerating fields in the GV/m range, offering a promising path to more compact and cost-effective acceleration compared to conventional methods. Structure-based wakefield accelerator (SWFA) technology provides a viable approach to implementing beam-driven wakefield acceleration. An experiment at the Argonne Wakefield Accelerator (AWA) will utilize dielectric-lined structures to explore multi-beam excitation of wakefields for wakefield-pulse shortening and mapping of the transverse wakefield topology. These structures were commercially sourced and require a thin metallic film deposited on their outer surface. The first part of this paper summarizes the preparation of these structures. In parallel, a two-bunch beam configuration is required to support the experimental investigation, where one bunch excites the wakefield and the second serves as a loading or probe bunch. The experimental generation and testing of this two-bunch scheme at AWA are presented in this work.