Modeling and simulation of transverse wakefields in PWFA

TL;DR

This paper develops a simplified model for transverse wakefields in plasma wakefield accelerators, benchmarks it against simulations, and uses it to optimize parameters for a high-energy accelerator with improved stability and efficiency.

Contribution

A simplified wakefield model parameterized by cavity aperture radius is introduced and validated against PIC simulations, aiding accelerator design optimization.

Findings

Transverse wakefields scale as 1/a^4, often exceeding conventional structures.

A parameter set with improved energy spread, stability, and luminosity was identified.

The model enables efficient parameter studies for high-energy plasma accelerators.

Abstract

A simplified model describing the PWFA (plasma wakefield acceleration) transverse instability in the form of a wake function parameterized only with an effective cavity aperture radius $a$ is benchmarked against PIC-simulations. This wake function implies a $1/a^4$ scaling of the transverse wakefields, which indicates transverse intra-beam wakefields typically several orders of magnitude higher than in conventional acceleration structures. Furthermore, the wakefield formalism is utilized to perform a parameter study for a \SI{1.5}{\tera\electronvolt} plasma wakefield accelerator, where the constraint on drive beam to main beam efficiency imposed by transverse wakefields is taken into account. Eventually, a parameter set with promising properties in terms of energy spread, stability and luminosity per power was found.