The Dielectric Resonator Wakefield Accelerator

The Dielectric Resonator Wakefield Accelerating (DWR) structure concept is presented. The DWR is a symmetric, rectangular dielectric loaded unit consisting of a central channel bordered by two narrow side channels; four slabs of dielectric are used to form the channels. The device is configured as a resonator, having reflectors at each end, which may be tuned to reflect only the desired wakefield modes. One or more drive bunches can traverse the central channel and set up intense wakefields that will accelerate a pair of witness bunches located in the narrow side channels and achieve an elevated transformer ratio. Accordingly, there is no need for a separate “transformer” structure. The proposed device is to operate at 285 GHz, providing a gradient of 500 MV/m after injection of 40, 2.5nC high energy drive electron bunches. This resonator can accommodate elongated bunches and operates in a nearly-single wakefield mode in which the transverse force on electrons accelerated at the center of the witness channel is small in comparison with the longitudinal force.