Optical control of the topology of laser-plasma accelerators

TL;DR

This paper introduces a novel twisted plasma accelerator that uses a helical laser beam to generate relativistic electron vortex beams with controlled angular momentum, improving energy gain and trapping efficiency.

Contribution

It presents a new method for controlling plasma wakefields using helical laser beams, enabling the generation of electron vortex beams with quantized angular momentum.

Findings

Twisted plasma wakefields can be excited by helical laser beams.

The method enhances energy gain and trapping efficiency.

Electron vortex beams with helical current profiles are generated.

Abstract

We propose a twisted plasma accelerator capable of generating relativistic electron vortex beams with helical current profiles. The angular momentum of these vortex bunches is quantized, dominates their transverse motion, and results in spiraling particle trajectories around the twisted wakefield. We focus on a laser wakefield acceleration scenario, driven by a laser beam with a helical spatiotemporal intensity profile, also known as a light spring. We find that these light springs can rotate as they excite the twisted plasma wakefield, providing a new mechanism to control the twisted wakefield phase velocity and enhance energy gain and trapping efficiency beyond planar wakefields.