A fully plasma based electron injector for a linear collider or XFEL

TL;DR

This paper presents a plasma-based electron injector capable of producing high-energy, high-quality electron beams suitable for linear colliders or XFELs, demonstrated through advanced particle-in-cell simulations.

Contribution

It introduces a novel plasma acceleration method utilizing self-focusing and self-injection to generate ultra-high quality electron beams with high efficiency.

Findings

Electron beams of ~20 GeV energy achieved

Beams have energy spread less than 1%

High normalized brightness and efficiency

Abstract

We demonstrate through high-fidelity particle-in-cell simulations a simple approach for efficiently generating 20+ GeV electron beams with the necessary charge, energy spread, and emittance for use as the injector for an electron arm of a future linear collider or a next generation XFEL. The self-focusing of an unmatched, relatively low quality, drive beam results in self-injection by elongating the wakefield excited in the nonlinear blowout regime. Over pump depletion distances, the drive beam dynamics and self-loading from the injected beam leads to extremely high quality and high energy output beams. For plasma densities of $10^{18} \ \text{cm}^{-3}$, PIC simulation results indicate that self-injected beams with $0.52 \ \text{nC}$ of charge can be accelerated to $\sim 20$ GeV energies with projected energy spreads, $\lesssim 1\%$ within the beam core, slice normalized emittances as low as $110 \ \text{nm}$, a peak normalized brightness $\gtrsim 10^{19} \ \text{A}/\text{m}^2/\text{rad}^2$, and energy transfer efficiencies $\gtrsim 54\%$.