EUCLID BEAMLABS LLC — Department of Energy SBIR Phase I: 26h

Description

In the last two decades, the theoretical and experimental investigations of dielectric accelerating structures for application to wakefield acceleration have predominantly used a dielectric-lined waveguide, due to its simple geometry (i.e. low fabrication cost). However, in comparison with the prevailing metallic disk-loaded accelerators, the dielectric-lined waveguide suffers from a lower Q-factor and lower shunt impedance. Taking the opportunity of DoE SBIR Program, we plan to develop a new dielectric-disk loaded accelerator (DDLA). The preliminary simulation shows that, even with 5e-4 of loss tangent dielectric material (eps=50), we can achieve ~200Mohm/m shunt impedance at 26GHz traveling wave operation (the beam aperture keep the same in the comparison), which is 4 times higher than those of the conventional dielectric loaded accelerator. Under Phase 1 of the project, we will focus on the structure and rf coupling design. Through fabrication of numbers of testing cells we will determine the optimum fabrication procedures for a single-cell DDLA structure, including study of metallization, brazing or other fabrication techniques, frequency tuning, etc. In order to validate the dielectric-based short-pulse wakefield Two Beam Accelerator concept on a relatively large scale without a significant budget increase, the High Energy Physics Division of Argonne National Laboratory plans to demonstrate a ~500-MeV module in the current Argonne Wakefield Accelerator facility within the next 5 years. A new high shunt impedance dielectric wakefield accelerator is the key element for this experiment. The knowledge and experiences gained in the project will benefit the accelerator community in general.