Energy spread minimization in a beam-driven plasma wakefield accelerator

TL;DR

This paper reports a novel experimental method in beam-driven plasma wakefield acceleration that achieves an ultra-low energy spread of about 0.1%, significantly improving beam quality for practical applications.

Contribution

It introduces an innovative approach to minimize energy spread in plasma accelerators, demonstrating a tenfold improvement over previous results.

Findings

Achieved an energy spread of approximately 0.1% in plasma acceleration.

Demonstrated the first experimental realization of ultra-low energy spread in this context.

Potential for enabling compact, high-quality plasma-based accelerators.

Abstract

Next-generation plasma-based accelerators can push electron bunches to gigaelectronvolt energies within centimetre distances. The plasma, excited by a driver pulse, generates large electric fields that can efficiently accelerate a trailing witness bunch making possible the realization of laboratory-scale applications ranging from high-energy colliders to ultra-bright light sources. So far several experiments have demonstrated a significant acceleration but the resulting beam quality, especially the energy spread, is still far from state of the art conventional accelerators. Here we show the results of a beam-driven plasma acceleration experiment where we used an electron bunch as a driver followed by an ultra-short witness. The experiment demonstrates, for the first time, an innovative method to achieve an ultra-low energy spread of the accelerated witness of about 0.1%. This is an order of magnitude smaller than what has been obtained so far. The result can lead to a major breakthrough toward the optimization of the plasma acceleration process and its implementation in forthcoming compact machines for user-oriented applications.