Transverse dimension effects in the dielectric wake-field accelerator

Abstract

The wake‐field amplitude and frequency of a dielectric wake‐field accelerator is calculated, taking into account the transverse dimensions of the wake‐field cavity, including the ratio of inner to outer radii of the dielectric liner S. It is assumed that the accelerator is driven by a linearly ramped current pulse with an infinitely sharp cutoff. The results indicate that the total wake‐field amplitude will have a significant contribution from the first two transverse magnetic modes (TM0 1 and TM0 2) of the dielectric lined cavity for S≤0.65. Additionally, the wake‐field amplitude of the fundamental mode (TM0 1) decreases as the ratio of inner to outer radii S increases. The theoretical results are shown to be in good agreement, when predicting the wake‐field frequencies, with recent results of an experimental test of the dielectric wake‐field accelerator concept.