Experimental Demonstration of Beam-Driven Wakefield Acceleration in Laser-Plasma Filament

TL;DR

This paper demonstrates experimentally that laser-generated plasma filaments can drive wakefield acceleration of electrons with high accelerating fields, offering a reliable, tunable, and potentially high-repetition-rate alternative to traditional plasma accelerators.

Contribution

It provides the first proof-of-principle experimental demonstration of beam-driven wakefield acceleration in laser-induced plasma filaments, validated by numerical simulations.

Findings

Accelerating field exceeds 250 MV/m in plasma filaments.

Laser plasma filaments are more reproducible and controllable than discharge plasmas.

Results align well with numerical simulations, confirming the physical mechanism.

Abstract

Self-guided femtosecond laser pulses propagating in low-pressure gas can generate plasma filaments, establishing a new framework for plasma wakefield acceleration. Unlike conventional schemes relying on mechanically confined or preformed plasma channels, this method exploits the intrinsic non-linear light-matter interaction, greatly reducing the energy required to generate plasma. This, in turn, allows to realise tunable stages, potentially operating above kHz repetition rate and with meter-scale interaction lengths and transverse sizes down to a few tens of micrometres. Moreover, the laser-plasma filament reproducibility is intrinsically higher than state-of-the-art discharge-plasmas, where the breakdown process is initiated in a stochastic and uncontrolled manner. As a result, laser-based plasma formation offers improved reliability and control over plasma parameters. Here we report a proof-of-principle experimental demonstration of beam-driven wakefield acceleration of electron bunches with an accelerating field exceeding 250 MV/m in a laser-generated plasma filament. The results are cross-checked with numerical simulation, showing an excellent agreement and providing a complete picture of the physical process. Beyond particle acceleration, the concept bridges laser filamentation physics, advanced plasma photonics and compact accelerator technologies, offering a promising route towards sustainable, high-repetition-rate plasma-based facilities.