Theory of wakefields excited by an off-axis drive bunch in a plasma-dielectric waveguide

TL;DR

This paper develops a linear theoretical model for wakefield excitation caused by an off-axis electron bunch in a plasma-dielectric waveguide, analyzing the spatial distribution of resulting wakefields.

Contribution

It introduces a new linear theory for wakefield excitation in plasma-dielectric structures with off-axis drive bunches, including numerical analysis of wakefield distributions.

Findings

Wakefields depend on off-axis injection parameters.

Spatial distribution of wakefields was characterized.

Implications for beam stability and acceleration efficiency.

Abstract

A linear theory of a wakefield excitation in a plasma-dielectric accelerating structure by a drive electron bunch in the case of an off-axis bunch injection has been constructed. The structure under investigation is a round dielectric-loaded metal waveguide with a channel for the charged particles, filled with homogeneous cold plasma. Derived theory was used to investigate numerically the spatial distribution of the bunch-excited wakefield components, which act on both the drive and witness bunches.