A comparison of the dielectric and plasma wakefield accelerators

A comparison of two advanced accelerator concepts, the plasma wakefield accelerator (PWA) and the dielectric wakefield accelerator (DWA), is presented. Emphasis focuses on the peak accelerating gradients and transformer ratios that can be achieved in these two devices. The effect of finite plasma size on the PWA is also analyzed. For the same cavity geometry and drive beam current, it is found that the dielectric wakefield accelerator can generate a peak field that is comparable to the field that can be generated in the plasma wakefield accelerator. Provided that ideal beam pulse shaping can be achieved, the transformer ratio for the PWA is ten times larger than that for the DWA. A change in this ideal pulse shape results in closer agreement for the transformer ratios. Given these encouraging preliminary results for the DWA it is concluded that the simplicity of employing a passive structure as an accelerating medium warrants further experimental testing of the dielectric wakefield accelerator