Design, fabrication, and low-power rf measurement of an X-band dielectric-loaded accelerating structure

Abstract

This paper presents the design, fabrication, and low-power rf measurement of an externally powered X-band dielectric-loaded accelerating (DLA) structure with a dielectric constant ϵ_{r}=16.66 and a loss tangent tanδ=3.43×10^{−5}. A dielectric matching section for coupling the rf power from a circular waveguide to an X-band DLA structure consists of a compact dielectric disk with a width of 2.035 mm and a tilt angle of 60°, resulting in a broadband coupling at a low rf field which has the potential to survive in the high-power environment. Based on simulation studies, a prototype of the DLA structure was fabricated. Results from low-power rf measurements and the comparison with simulated values are presented. A significant discrepancy was found between measurements and simulations. The detailed analysis on the fabrication errors which may cause the discrepancy is also discussed.