TRANSVERSE DIMENSION EFFECTS IN THE DIELECTRIC WAKE-FIELD ACCELERATOR

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 (TM01 and TM02) of the dielectric lined cavity for S≤0.65. Additionally, the wake-field amplitude of the fundamental mode (TM01) 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. © 1989 American Institute of Physics.