Optmized stability of a modulated driver in a plasma wakefield accelerator

TL;DR

This paper investigates the stability of a modulated beam in plasma wakefield accelerators, aiming to optimize bunch positioning to enhance stability and minimize particle loss, supported by semi-analytical analysis and 3D simulations.

Contribution

It introduces a semi-analytical method to determine optimal bunch positions for stability in modulated plasma wakefield drivers, validated by 3D PIC simulations.

Findings

Optimal bunch positioning enhances stability.

Beam front expansion causes backward shift and potential particle loss.

Proper configuration maintains accelerating field and reduces driver deterioration.

Abstract

We analyze the transverse stability for a configuration of multiple gaussian bunches subject to the self-generated plasma wakefield. Through a semi-analytical approach we first study the equilibrium configuration for the modulated beam and then we investigate the evolution of the equilibrium configuration due to the emittance-driven expansion of the beam front that results in a rigid backward shift. The rear-directed shift brings the modulated beam out of the equilibrium, with the possibility for some of the bunch particles to be lost with a consequent deterioration of the driver. We look therefore for the proper position of the single bunches that maximize the stability without severely affecting the accelerating field behind the driver. We then compare the results with 3D PIC simulations.