A theoretical and experimental investigation of anisotropic-dielectric-loaded linear electron accelerators

The general properties of linear accelerator waveguides loaded with spaced discs of ceramic dielectric are investigated theoretically and these waveguides are shown to have a higher shunt impedance than all-metal waveguides. Theoretical and experimental methods of waveguide design follow, a combination of which is used to design an experimental linear electron accelerator. Early experience with the accelerator shows considerable excess attenuation, which is probably associated with a high secondary-emission coefficient of the carbonaceous deposits formed; this is later eliminated by using mercury instead of oil-diffusion pumps. Provided that suitable precautions, such as the use of a mercury pump, are taken it is concluded that the way lies open for further development of dielectric-loaded accelerators, with considerable potential advantages.