Twisted waveguides for particle accelerator applications

A novel microwave device for accelerating charged particles based on twisted waveguide is presented. Twisted guides support slow-wave TM modes whose phase velocity could reach the speed of light c. The axial electric field in these structures can travel synchronously with the particles to achieve nearly uniform acceleration in a traveling-wave topology. The advantages of using twisted guides over conventional RF accelerating cavities are discussed. We present two types of twisted accelerating structures, one analogous to the well-known disk-loaded accelerating structure, and the other analogous to the popular elliptical (or TESLA-type) accelerating geometry. The propagation characteristics of these two structures are considered, and prototypes are made to experimentally validate our theoretical results.