Three-Dimensional Analysis of Wakefields Generated by Flat Electron Beams in Planar Dielectric-Loaded Structures

TL;DR

This paper provides a comprehensive 3D analysis of wakefields generated by flat electron beams in planar dielectric structures, offering analytical expressions, simulation validation, and integration into particle tracking software for accelerator design.

Contribution

It extends previous work by deriving closed-form solutions for mode frequencies and field amplitudes, and implements a semi-analytical algorithm into simulation tools.

Findings

Analytical expressions for mode frequencies and field amplitudes.

Validation of analytical results with FDTD PIC simulations.

Implementation of a semi-analytical model into particle tracking software.

Abstract

An electron bunch passing through dielectric-lined waveguide generates $\check{C}$erenkov radiation that can result in high-peak axial electric field suitable for acceleration of a subsequent bunch. Axial field beyond Gigavolt-per-meter are attainable in structures with sub-mm sizes depending on the achievement of suitable electron bunch parameters. A promising configuration consists of using planar dielectric structure driven by flat electron bunches. In this paper we present a three-dimensional analysis of wakefields produced by flat beams in planar dielectric structures thereby extending the work of Reference [A. Tremaine, J. Rosenzweig, and P. Schoessow, Phys. Rev. E 56, No. 6, 7204 (1997)] on the topic. We especially provide closed-form expressions for the normal frequencies and field amplitudes of the excited modes and benchmark these analytical results with finite-difference time-domain particle-in-cell numerical simulations. Finally, we implement a semi-analytical algorithm into a popular particle tracking program thereby enabling start-to-end high-fidelity modeling of linear accelerators based on dielectric-lined planar waveguides.