A Metamaterial Wagon Wheel Structure for Wakefield Acceleration by Reversed Cherenkov Radiation

Xueying Lu, Manoel Conde, Chunguang Jing, Ivan Mastovsky, John Power, Jiahang Shao, Michael Shapiro, Richard Temkin, Eric Wisniewski, Schaa, Volker RW (Ed.), Satogata, Todd (Ed.)
We present the design and experimental operation on an X-band metamaterial (MTM) wagon wheel structure for wakefield acceleration. The structure was designed and fabricated at MIT, and tested at the Argonne Wakefield Accelerator (AWA) laboratory at Argonne National Lab. The MTM wagon wheel structure is an all-metal periodic structure at 11.4 GHz. The fundamental TM mode has a negative group velocity, so when an electron beam travels through, energy is extracted from the beam by reversed
more » ... by reversed Cherenkov radiation, which was verified in the experiment. Single bunches up to 45 nC were sent through the structure with a beam aperture of 6 mm and generated microwave power up to 25 MW in a 2 ns pulse, in agreement with both the analytical wakefield theory and the numerical CST simulations. Two bunches with a total charge of 85 nC generated 80 MW of microwave power. The structure is scalable to a power extractor of over 1 GW by increasing the structure length from 8 cm to 22 cm.
doi:10.18429/jacow-ipac2018-thpml014 fatcat:zzbimywp5baxdou7s43xcxj6v4