Generation of 565 MW of X-Band Power for Structure-Based Wakefield Acceleration Using a Metamaterial-Based Power Extractor

This work presents the generation of 565 MW of power at 11.7 GHz with a metallic metamaterial-based power extractor for structure-based wakefield acceleration (SWFA). To our knowledge, this is the highest power level reported in an SWFA experiment. Metamaterial use in a power extractor design allows the structure to overcome some of the limitations faced by other SWFA techniques. Two previous experiments, Stage I in 2018 and Stage II in 2019, have successfully demonstrated the functionality of this approach by generating high power pulses using the 65 MeV electron beam at the Argonne Wakefield Accelerator (AWA) facility. Here, we cover the design and results of the Stage III experiment. The Stage III structure includes significant improvements to increase output power, including an all-copper structure, fully-symmetric output coupler design, and breakdown risk-reduction treatment.