High Power RF Generation at W-band Based on Wakefield Excited by Electron Bunch Train

We present the planned experiment on high power RF generation at W-band, based on the coherent wakefield from the metallic periodic structure of 91 GHz, excited by intense charged bunch train at the Argonne Wakefield Accelerator (AWA) facility. The output RF peak power is expected to be similar to 100 MW and the electrical field gradient can reach up to 400 MV/m, with RF pulse duration adjustable from few ns to 30 ns when excited by the bunch train of 75 MeV, with 5 similar to 10 nC charge in a single bunch and up to 32 sub bunches in total. We report the design and bench test result of the W-band structure, introduce the basic theoretical background of RF generation excited by bunch train and numerical simulation results from CST wakefield solver, which agree well with the analysis. We also design the RF measurement setup, with an 8th harmonic mixer to measure the frequency and a small witness beam to measure the wakefield in the structure. All prepared work goes well and we will perform this experiment in the near future.